Aces High Bulletin Board
General Forums => Aircraft and Vehicles => Topic started by: Straiga on May 07, 2004, 04:00:34 AM
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Any of the 109s in AH and a many others, I just cant figure it how its flys.
I set the autopliot and look at the trim settings and its at cruise speed. Elevators trim looks good, the rudder is neutral and airleron trim is set way to the right, showing the left airleron down and right aileron up but the ball is centered showing the airplane cordinated flying straight and level.
Shouldnt the rudder be trim to the right also to be cordinated for the roll moment and then showing the ball centered, or was there a change in physics in the AH world that I should know about. When you use aileron, you get a roll moment but you also get a yaw moment with out rudder. Now one wing speeds up because of a decrease in lift and drag (right wing) and one wing slows down because the increase in lift and drag (left wing). Because of the roll the ball (yaws) moves to the inside of the turn with out rudder and with aileron still deflected rudder cant be neutrally trim ( 0 rudder deflection) to be cordinated (Ball Centered) you would have to use right rudder. There is no way but in the AH world. Can anybody explain this to me.
CYA
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hmm, well im no expert. but doesnt the engine produce both roll and yaw?
so the ailrons counter both roll and yaw, plane goes straight.
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Afaik the real 109 had the rudder set on groud for cruise speed.
And had IRL no if I'm not mistaken other trim than elevator trim.
So if AH model a rudder already set for cruise even having aileron and elevator trim there should be no need to trim rudder.
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Hi Straiga,
Since propeller aircraft like the Me 109 are often designed asymmetrically to ameliorate propeller effects, a single flight condition is not sufficient to judge the model. Try changing the power setting and observing what trim changes are required to established straight flight at the new power setting. That'll be probably a good baseline for comparing it to real-world behavior.
Regards,
Henning (HoHun)
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i thought 109 had fixed wing trim
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Originally posted by HoHun
Hi Straiga,
Since propeller aircraft like the Me 109 are often designed asymmetrically to ameliorate propeller effects, a single flight condition is not sufficient to judge the model.
Regards,
Henning (HoHun)
Indeed the Bf 109s had assymetric vertical tail, that created lift sideways to counteract torque forces.
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Originally posted by VO101_Isegrim
Indeed the Bf 109s had assymetric vertical tail, that created lift sideways to counteract torque forces.
But it still did stop LW pilots having one leg 'fatter' than the other from pushing on the rudder peddle to counter what trim adjustment would have been able to do.
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Originally posted by MiloMorai
But it still did stop LW pilots having one leg 'fatter' than the other from pushing on the rudder peddle to counter what trim adjustment would have been able to do.
Why would it be neccesary, ie. there were fixed trim tabs on the rudder, set to give neutral trim in cruising conditions, basically no footload was neccesary during transits, but only in combat, where the speed and change changes were so rapid that trimming couldn`t be used anyway, at least not with an advantage, applying rudder was far more easier to do. Not to mention rudder forces were very light on the Bf 109s. I never heard any 109 pilot complaining about the lack of rudder trim. If it would be problem, they would change it in a week.
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That is correct, set for one particular cruising speed. If the speed was 15kph higher or lower than the set speed, the application of rudder was required. One direction for above the set cruise speed and the other direction for below the set cruise speed. Since LW pilots spent more time at speeds above the set cruise speed one leg would be more muscular than the other. (one does not cruise at economical cruise in a combat zone)
Imagine holding hard rudder for 5-10-15min while diving away from Allied fighters at twice the set cruising speed..:eek:
One does not make complaints about what is second nature to themselves. 109 pilots naturally applied the correct rudder correction required and over time, the muscles in that leg would increase through useage.
LW pilots testing Allied a/c, commented on how nice it was to have a cockpit trimmable rudder.
But I forget, the 109 was the perfect a/c.:p
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Imagine holding hard rudder for 5-10-15min while diving away from Allied fighters at twice the set cruising speed..
How could that be possible, Milo? 15 min dive towards the ground? That would be... uhm.. 20 km/h dive speed (hypothesizing vertical dive from 5000m)? :lol
Ie. 'combat' cruise speed was ~400mph for the Bf 109s, so you say it could maintain 800 mph in dive? Nice feature...
BTW, I do to that in my car, ie. I have to apply constant force on gas pedal in my car. I wunder how many car owners suffer the same, because they use the gas pedal constantly, and the clutch only occasionally... For hours! Horrible, unbearable experience, really. :)
LW pilots testing Allied a/c, commented on how nice it was to have a cockpit trimmable rudder.
Perhaps you could share us a quote?
(Oh jesus)
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Originally posted by VO101_Isegrim
Imagine holding hard rudder for 5-10-15min while diving away from Allied fighters at twice the set cruising speed..
How could that be possible, Milo? 15 min dive towards the ground? That would be... uhm.. 20 km/h dive speed (hypothesizing vertical dive from 5000m)? :lol
:D:D All dives are vertical????? Show some intelligence for a change.
Ie. 'combat' cruise speed was ~400mph for the Bf 109s, so you say it could maintain 800 mph in dive? Nice feature...
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Rudder trim was set for economical cruise speed.:) Now which model of 109 is that for. That ~400mph is faster than the top speed of some models.:)
BTW, I do to that in my car, ie. I have to apply constant force on gas pedal in my car. I wunder how many car owners suffer the same, because they use the gas pedal constantly, and the clutch only occasionally... For hours! Horrible, unbearable experience, really. :)
[/b]
The force applied to the gas peddle is nowhere comparable to the force required on the rudder bar/peddle. Dumb example.:rolleyes: If you flew real a/c, you would know this..
LW pilots testing Allied a/c, commented on how nice it was to have a cockpit trimmable rudder.
Perhaps you could share us a quote?
Why, you would not believe it anyways as you do with anything that shows the 109 or anything German was not perfection.:)
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Simply rudder trim was not seen as requirement for lightweight, short ranged interceptors in Germany. Rightly so. Rudder trim was to be installed at and above 5 tons weight.
It appears in the Milo Morai vs. Ubi Forum Moderators, the latter triumphed. :aok
Rightly so! :rofl
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The 109's rudder trim tab was adjustable on the ground. They could set it according to their mission profile. The maximum operational endurance (with droptank) was 1 hour 20 minutes, most of that time was spent climbing and cruising.
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gee Barbi, the Fw190 was not a light weight a/c nor as short ranged as the 109 and it did not have any cockpit adjustable rudder trim.:rofl Even the light He112 had rudder trim.
The Russians showed more smarts than the Nazis by putting rudder trim on their light shortrange La a/c.:)
Care to look at some light a/c, that have cockpit trimming on all 3 axis control surfaces.
Now would you like to try coming up with another lame excuse?:)
The UBI Moderators are a joke and a farce, especially Tully. If Tully had a brain, he would be dangerous. I gave up on them a few months ago with their continued bias and preferential treatment towards certain posters who still are posting 'insulting, derogatory' posts.(see the P-51 thread in ORR for examples) There are enough ppl around to keep you in check with your Nazi Germany is uber BS propaganda and even more ppl that know what you post is mostly bs.
I noticed you made no comment on the doc Neil Sterling linked to that had production of 150pn fuel for which you claimed that ~only 6500t was produced.
"this 150octane is an possible-option, only ~6500t/year 150octane were produced. it was used to hunt v1's not to fight german fighters."
Yet British only production was
http://hometown.aol.co.uk/JStirlingBomber/150y.jpg
369,385t in a year (55.7% of total production) is a VERY long way from your ~6500t. Typical Barbi bs. :rofl :rofl
You did not make one of your usual insulting derogatory post to Neil S about the use of 150pn fuel used by operational Tempests. Why is that? Could it be because you said Tempests never used 150pn fuel. Barbi continues with his bs lies.:)
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Milo Morai I don't know what is your problem but maybe changing medication could help :)
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Staga can I try yours?:D:D:D:D
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Im sure that LW pilot or any other pilot in the heat of battle sat in the cockpit trimming the airplane to make it fly straight. In the pitch attitude if it was trim in and around combat manuvering speed that would be good enough. Rudder trim was about the same way when rolling left or right giving equal leg work out. But aileron deflection during straight level flight shoundnt be there.
Airplanes are rigged to fly in equalibrium, just for talk lets say a plane is at fast cruise, the ailerons should be neutral because remember the plane is rigged to do so, and rudder can keep the wings level. Elevator trim to nose down from a center postion, because at fast speed the main wing creates a lot of lift and from preventing the airplane from climbing you need to trim nose downor just hold forward pressure on the stick, now you right hand will get a work out. Rudder trim should be to the right the P-51 on take off alone needs trim set to 7 degrees to the right thats alot. Yes planes do have fixed trim tabs can you can adjust on the ground todays airplane still have them.
Now we have a plane in equalibrium its not increasing or decreasing speeds, its not climbing or desending, and its not rolling. Its in equalibrium. If we increase power the plane will accelerate in crease thrust over drag, you get a roll moment from increase torgue a little can take care of that because of the way the plane is rigged to fly, and you need more down pitch trim because of an increase speed (more lift). Ailerons are neutral still.
Now the airplane can not increase any more speed so drag equals thrust again, rudder is decreased because torgue has decreased, and elevator trim set for new airspeed change, and the airplane is equalibrium again.
My concern is when an airspeed change takes place in the AH planes you have to keep trimming aileron to keep wings level. If you have a plane in equalibrium and pitch the nose over with out power change why does the airplane roll due to increase of airspeed. Im sorry this is wrong. Every airplane I have ever flown for a living, I dont have to trim aileron or have to fight a rolling moment in the plane to keep wings level. because the airplane is rigged to fly that way. I can pitch the nose over increase alot of airspeed and for some reason the wings stay level, what no roll momet. When a combat pilot has to constantly change aileron trim so he doesnt have to fight the airplane from trying to roll on him all the time he will lose the fight. If the plane had a roll tendancy aileron trim should be neutral anyway and the force for aileron responce can be handeled with little aileron stick force. Not all airplanes have aileron trim, because the airplane is very stable in the roll moment and trim is not nesassary.
Aileron trim or aileron force is very little used in every day flying, except for unbalanced fuel loads between one wing to another, or one bombs still on one wing and you have to fly with it for awhile, or s lost engine on a mutli-eng airplane, but you have to use rudder for increase yaw moment in all these applications too.
The way AH uses aileron trim is incorrect. Cant we get a plane that you can dive on some one without the plane trying to go were you dont want it to go. Frankly the 262, p-38, me-163 in AH fly like any of the single engine prop airplanes I have flown in the real life and all AH planes should to. Airplane are so easy to fly in all three axises, that trim is not nessassary except for elevator trim and may be a little rudder too.
Later Guys
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Originally posted by MiloMorai
Staga can I try yours?:D:D:D:D
I don't think Aspirin helps much in your case :)
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Originally posted by Staga
I don't think Aspirin helps much in your case :)
Maybe he should try rat poison? That would fix him. :D
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lol
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The lack of rudder trim on the 109 WAS a problem. Many Luft pilots did have the "fat" leg from pushing the rudder in constantly.
Here is Col. Kit Carson's comments:
"The absense of a rudder trim control in the cockpit was a bad feature at speeds above cruise or in dives. Above 300 mph the pilot needed a very heavy foot on the port rudder pedal for trimmed flight with no sideslip which is absolutely essential for gunnery. The pilot's left leg quickly tired while keeping this load on, and this affected his ability to put on more left rudder for a turn at 300 mph or above. Consequently, at high speeds the 109 could turn far more readily to the right than to the left."
"Anyone who believes that he can satisfactorily demonstrate which WWII fighter was the "best" out of the whole bag that appeared from 1940 to 1945 is incredibly naive. There are so many performance variables and kinds of missions, that arguing them to all to a bedrock conclusion that would convince everyone is virtually impossible. There were a few generally acknowledged leaders, however, fighters which became household words the world over: the Spitfire, Mustang, Thunderbolt, Focke Wulf 190 all proved themselves in the crucible of war. The Me-262 was the first operational jet fighter and a dazzling achievement, years ahead of anything we had. But another household work, the highly propagandized Me-109G, was obsolete when it was built and was aerodynamically the most inefficient fighter of its time. It was a hopeless collection of lumps, bumps, stiff controls, and placed its pilot in a cramped, squarish cockpit with poor visibility."
Col "Kit" Carson was a P51 pilot in WWII And an aeronautical engineer.
Here is his comments on the FW-190:
"FW-190A
A superb airplane, every inch a fighter. It could do a half roll at cruising speed in one second. Taking this in conjunction with the airplane's high top speed and rate of climb one expected its pilots to exploit its high speed qualities to the fullest without staying in there to "mix it up" in a low speed, flaps down full throttle, gut wrenching dog fight.
They did. The 190 pilots had a good airplane and some good advice. Nearly all of my encounters with the 190 were at high speeds. On at least two occasions when I met them, in my Mustang started porposing, which means I was into compressibility, probably around 550 mph. I don't know what my air speed indicator was reading, I wasn't watching it.
On another occasion, I jumped one directly over the city of Paris and fired all my ammo, but he was only smoking heavily after a long chase over the town. Assuming I was getting 10 percent hits, that airplane must have had 200 holes in it. It was a rugged machine."
It took the 109G6 4 seconds to do a 45 degree roll at 440 IAS.....
Crumpp
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Crumpp,
You got it right.
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Hi Crumpp,
>Col "Kit" Carson was a P51 pilot in WWII And an aeronautical engineer.
And he was biased to the point of no return.
Here's some nonsense from his article:
"The Spitfire was an aerodynamically clean airplane to start with, having a total drag coefficient of .021 at cruise. The Me-109 had a coefficient of .036; drag coefficiency and of the horsepower required to haul 'em around. Like golf scores, the lower the better, and no fudging.
Drag coefficient is the score for one hole, but total drag is the score for the entire course. Messerschmitt accepted a higher drag coefficient in favour of a smaller frontal area. That he was successful is evident from the observation that the Me 109 always achieved similar top speeds on similar engine power as the Spitfire.
If the Messerschmitt would have needed much greater power for the same top speed, it would have blown the Spitfire away at low speeds because the drag coefficient doesn't have much of an impact there. As you know, that didn't happen.
Quite obviously, Carson points to a secondary parameter (with great gesture) to make the Me 109 look bad. Either he's incompetent, or he's out to manipulate the reader.
Whether it's the one or the other, he's not a good source.
Regards,
Henning (HoHun)
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Originally posted by VO101_Isegrim
Maybe he should try rat poison? That would fix him. :D
I doubt that since it has no effect on you, being your favorite medicine.:)
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Crumpp, though we have had our differences in the past, that is ancient history. You have much more intelligence than the Nazi Germany luver, Barbi.
Thanks for the support, but I must warn you that Barbi(Isegrim) will be all over you for quoting the Nobody** Carson, as he has done to many others in the past. ** luftluver's word ;)
If you really get him wound up tell him that the LW was a spent force even as early, as say, 1944. This P-51 thread should prepare you. http://ubbxforums.ubi.com/6/ubb.x?a=tpc&s=400102&f=63110913&m=953109383
This one is good as well http://ubbxforums.ubi.com/6/ubb.x?q=Y&a=tpc&s=400102&f=23110283&m=77910535&p=1
Unfortunately the thread was locked and several pages of his posts were deleted and could not answer this statement by his bud Huckles "When measure the engine, don't forget to add the supercharger weight. A Merlin engine without its supercharger is a useless piece of scrap metal. Now compare the weights of superchargers. See the difference?
Also compare them in size with superchargers attached.". What the German luvers fail to add is the extra weight associated with the 'boost juices' to give the high HP numbers of the DBs.:rolleyes: It should be noted that the sc weight was include in the weight of the Merlin. This is the sort of intelligence??? one has to contend with.
Just so you know were his nick Barbi comes from, it is from one of his nicks Barbarossa Isegrim.
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How about taking your personal problems to some other board and leave AH's "Aircraft and Vehicles" for, you guessed it, Aircraft and Vehicle discussion?
Oh and quoting Carson makes people look stupid :aok
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Staga, if you did not notice, it was Barbi that did the originating. Kindly direct you comments that way.:)
Oh, and the links provided were a/c discussions with cordial posts, except for those posts made by your hero.:)
Now tell me, what is wrong with warning Crummp what he is in for?
Have a nice evening.:aok
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I absolutely do not understand your fantasy that German planes were the end all in performance.
Carson's conclusion's are valid. They are HIS impressions and are based on his experience. He is certainly much more qualified than ANYONE in this forum to comment on the flight characteristics of the 109.
In fact I can find absolutely nothing that contradicts Willy Radinger, Woflgang Otto, Jochen Prien, Peter Rodeike, Eric Brown, Alfred Price, OR ANY authority or pilot of the 109.
Lack of rudder trim WAS a fault in the 109 design and it did cause problems for the pilots. Any claim otherwise is sheer wishful thinking. It certainly was not some grand teutonic scheme to make the plane more efficient nor was it an "unnecessary" luxury.
If it was so great why does ADOLF GALLAND call it an obsolete design in 1943??
Reason Number 4, under the "Most Important Mistakes of the Luftwaffe as seen from the German Fighter Force" in the book "The Luftwaffe Force: A view from the Cockpit"
For this reason (production and development politics) the Me.109 was not taken out of series production for years, althought was absolutely necessary on the basis of performance figures from 1943 on. Similarly the beginning of the new series of FW 190 and of the Tank 152 was so delayed as to be almost ineffective.
Crumpp
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Carson's conclusion's are valid. They are HIS impressions and are based on his experience.
What experience? He never flew a 109. He is also full crap.
If don't know this then thats your failing not anyone elses.
You see once you look at his "impression" in detail and compare that with known facts his opinion doesnt hold water.
Every 6 months someone ignorant of the 109 posts Carson as some sort of established authority. He is so wrong that as HoHun you have no choice except to believe he is purposely distorting the facts, the obvious conclusion is he hates the 109.
Thread on this forum and 100 others have went through and ripped his "impression" part.
Carson is just plain wrong...
Oh and quoting Carson makes people look stupid
That's a fact....
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The Carson 109 article is incredibly flawed.
I remember reading the whole thing before and it really seems like has no practical experience about flying the Bf109.
In fact it particularly strikes me that he even seems to confuse various models of the Bf109 and mish mas all their features as if it made no difference - thats not a sign of expertese.
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Hi Crumpp,
>Carson's conclusion's are valid.
Did the Me 109 fly rings around the Spitfire at low speed? If Carson were right, it would have done that.
>If it was so great why does ADOLF GALLAND call it an obsolete design in 1943??
You can find that in his "Die Ersten und die Letzten": Galland wasn't satisfied with performance parity, but he strived for technological superiority to counter the numerical superiority of the Allies.
Regards,
Henning (HoHun)
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I put a question out.
If there was no problem with the, so-called, light rudder of the 109, why was the Flettner tab introduced?
The Flettner tab was used to ease the force applied to the rudder. Flettner tabs were even applied to the ailerons of 10% of the late model 109Ks. (as per Butch2k)
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Let me follow your logic:
Carson's views are not valid HOWEVER Gallands "First and the Last" is a valid source???
HoHun, you completely blew your crediability with that logic. I would say your are advancing an agenda.
Crumpp
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Originally posted by Crumpp
Let me follow your logic:
Carson's views are not valid HOWEVER Gallands "First and the Last" is a valid source???
HoHun, you completely blew your crediability with that logic. I would say your are advancing an agenda.
Crumpp
Do you understand the word "parity?"
Do you understand the word "superiority?"
And no Carson is not a valid expert source here.... HE NEVER FLEW A 109. NEVER! His analysis is based on a bunch of second hand information and he has no clue about which model 109s hes talking about, freely lumping in all sorts of 109 types as if they were all the same. He is not an expert on the 109.
But galland flew 109s for a nuber of years...
Crummp I ask what is your agneda when you try to say that carson is equally an expert on the 109 as was galland?
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Read this:
Why Carson was wrong (some call him an idiot) (http://mitglied.lycos.de/luftwaffe1/Carson/Carson.html)
Ecke
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1)
Carson's article is fantasy, put together from various other sources, showing technical cluelessness and he never flew a 109.
Carson's article is not a source, it is a joke. Sorry.
2)
The only time any of the Me 109 war pilots I've personally spoken with commented anything negative about the lack of rudder trim was when they had to fly of the those "bad" airframes. Those that were badly built or damaged and didn't fly well, those planes might require constant pedal pressume to fly straight.
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Hi Crumpp,
>Let me follow your logic:
>Carson's views are not valid HOWEVER Gallands "First and the Last" is a valid source???
Carson's views display an inherent contradiction.
Galland's views don't display such a contradiction. However, they provide an answer to your question on why he'd have liked to have the Me 109 replaced.
(And even if Galland's views were self-contradicting, that would be more a problem of his credibility than of mine :-)
With regard to the contradiction in Carson's views, it's pretty obvious if you have some aerodynamics knowledge. I admit that it might not be as self-evident as I had hoped it would be, so if you're interested, I can try to give a more detailed explanation than provided above.
Regards,
Henning (HoHun)
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That Carson guy doesnt worths 1/10th the typing that was spent correcting his crap. This is so, just plain and simple.
Really the funniest part is when he rants about 'how to make a 400mph+ airplane', claims 'Willy' never did that, and then mentions the G-10 which even according to his date did quite a bit more than just 400mph... I guess Carson would be shocked to know the F-4 already achieved that, and incorporated many of the improvements he speaks of. But he doesn`t even know that...
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With regard to the contradiction in Carson's views, it's pretty obvious if you have some aerodynamics knowledge. I admit that it might not be as self-evident as I had hoped it would be, so if you're interested, I can try to give a more detailed explanation than provided above.
I know I would like to hear some of those explanations!
I'm aeronautically impaired, and have always wondered just exactly what Carson was so wrong about.
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The Bf109K4 is faster than a P51D Mustang....
The next model, the Bf109K-14 with a new 2spped 2 stage supercharged engine and four blade prop would likely be in the same speed class as the P51H... Plus remember it would have flettner tabs to help high speed roll rate. And it could mount new weapons like the Mk103M or a new 900rpm firing Mk108 (50%more firepower than our 30mm). I'd say its was doing awesome for a 1934 design... :)
In other words Carson really did not know much about the Bf109 when he wrote that article. And you cant blame him, there was much misundertanding and little real research and knowledge about LW planes back in the 1970s.. But thats not an excuse now, and thus his article is not very valid.
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Well, this was all about rudder trim in the beginning. Barbi wants a source, I'll give one, and it's not Carson.
"In October 1940 I flew a captured Me 109E; to my surprize and relief I found the aileron control of the German every bit as bad - if not worse - at high speeds as that of the Spitfire I and II with fabric-covered ailerons. They were good at low and medium speed, but at 400 mph and above they were almost immovable. I thought the Me 109E performed well, particularly on the climb at altitude, and it had good stalling characteristics under G except that the leading edge slats kept snapping in and out. But it had no rudder trimmer - which gave it a heavy footload at high speed - while the cockpit, the canopy and the rearward vision were much worse than in the Spitfire. Had I flown the Me 109 earlier I would have treated the aeroplane with less respect in combat"
(Jeffrey Quill)
However, from memory mind you, I think that later models of the 109 had this fixed.
The Spitty on the other hand could be trimmed to fly hands off at almost any speed.....
Note the comments about the ailerons and the visibility...
(flame cookie away, :D )
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Still waiting for an explaination as to why the Flettner tab was added to the rudder.
While that is being explained, can anyone explain why the Flettner tabs were also installed on the ailerons.
Must be some truth to the high control forces required by the pilot for manuevering at high speeds in the 109.
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Kit Carson's article is based on Eric Browns "Enemy flight detachment" reports. Lets go to the source.
From Eric Browns "Wings of the Luftwaffe". The plane actually being flown is a Bf-109G6/U2 with the underwing gondolas. The test flight had a "steady diet" of 109's throughout the war begining with a 109E3 and ended flying a 109G14/AS. Postwar even more types were flown and evaluated.
"A see-saw battle for supremacy developed until 1942 when the Spitfire Mk IX widened the performance gap and the Bf-109 dropped off the chart to be replaced by the FW-190A"
"......if not a great fighter from the pilots viewpoint the Bf-109G was of vital importance to the Luftwaffe on every front the service was committed and a warplane worthy of respect"
"Another shortcoming was the lack of any rudder trimming device. This meant it was neccessary to apply moderate right rudder during the climb and considerable left rudder during a dive. "
"At its rather disappointing low level cruising speed of 240 mph the Gustav was certainly a delightful to fly, but the situation changed as speed increased; in a dive at 400 mph the controls felt as if they siezed!"
"However, if kept in its element, above 25,000 feet, the 109G performed efficiently as both a dogfighter and a bomber interceptor"
Eric Brown was hardly advancing an agenda other than figuring out the best tactic to shoot down Luftwaffe planes. The man lived in Germany almost half his life. His liking and respect for all things German oozes through his evaluations. Are they the end all word on Luftwaffe Iron?? Of course not, the RAF didn't have access to Daimler mechanics or factory trained techs to maintain the planes. So with that being said lets check out an official RLM document from the folks who did have the techs to maintain the planes.
Hauptman Gollob's and Test pilot Heinrich Beauvais comments from the earlier mentioned 109 vs 190 test. The aircraft being flown are a Bf-109F-4 and an FW-190A2.
The test is reprinted in "Focke-Wulf FW 190A: An illustrated History of the Luftwaffe's Legendary Aircraft" by Deitmar Hermann, Ulrich Leverenz, and Eberhart Weber.
"The FW 190's control Forces were rated as low. Even at 700 km/h the aircraft can be flown with acceptable control forces, unlike the Bf-109F4. Manuverabiliity is good and noticabley superior to the Bf-109F4, especially in reversals at higher speeds. The FW-190's rolling ability represents a significant advance which will have positive effects in aerial combat. It has yet to be determined whether the FW-190 turns tighter than the Bf-109."
According to Beauvis there was tendency to disbelieve the turning radius of the 190 amoung the engineers. He states that although turn radius was not actually measured during the test, based on turn times, the 109F was clearly superior to the 190A2. He also states that Hauptmann's Gollobs attitude was typified by his choice of callsigns. "Adler" for himself, and "Otto" for Beauvais!
Kit Carson is not wrong in his generalizations on the 109G. It is simply third hand information for the most part. However they still hold true especially when you factor in the altitude variable.
Crumpp
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Milo,
You know very well Flettner tabs weren’t "common".
Angus,
Did you read what you quoted? Tell me how you think it relates to what Isegrim said. Go back and read what was written.
Even so,
which gave it a heavy footload at high speed
you can't get any more ambiguous then that.
Crump,
Carson doesn't know wft he’s talking about. He has been beaten to death for years on many forums. Maybe HoHun will have more patience and go through and debunk the obvious for you but I doubt any one else will waste anymore time reading your opinions on the validity of Carson. It is just nonsense.
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Batz, every 109K-4, the G-10s and the G-14ASs had a Flettner tab on the rudder. That is, at a minimum, 8000 a/c. There is even documentation that the G-6AS (686 produced) had a rudder Flettner tab.
How can you say they were not common when that is around 25% of 109 production?
Milo,
You know very well Flettner tabs weren’t "common".
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Batz, please be more specific. What line from Isengrim? The 400 mph control heaviness & the 109's speed?
Honestly :confused:
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Actually didnt read your post, well I read it but wasn't "reading it". I thought you were baiting him into another "flettner tabs for ailerons" like the ubi threads.
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Now that Ubi thread brought many a chuckle, rolling eyes and slow head shakes with the incredulous posts by the 'luvers'.:)
Anyways, there had to be a reason why the Flettners were installed.
Just to put to rest my tag as a German 'hater', used by some people, the only a/c I 'fly' are those of Kurt Tank. Only real pilots 'fly' his a/c.;);):aok
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I think the idea that the LW had fat leg is an urban legend.
As Mark Hanna say (109J):
The speed's picked up to the '109 cruise of about 235-240 mph and now the tail is right in the middle and no rudder input is necessary.
from http://www.bf109.com/flying.html
But it's true above cruise speed (109E) :
Absence of rudder trimmer is a bad feature, although at low speeds the practical consequences are not so alarming as the curves might suggest, since the rudder is fairly light on the climb. At high speeds, however, the pilot is seriously inconvenienced, as above 300 mph about 2 1/2 degrees of port (left) rudder are needed for flight with no sideslip and a very heavy foot load is needed to keep this on. In consequence the pilot's left foot becomes tired, and this affects his ability to put on left rudder in order to assist a turn to port (left). Hence at high speeds the Bf 109E turns far more readily to the right than to the left.
From RAE trial on the same page.
Concerning the flettner tab,if I remember correctly the rudder is setup on ground ,perhaps the flettner tab are easier to tune than the previous system ?
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check this Milo : http://109lair.hobbyvista.com/techref/structures/tails/talltail.htm
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Rudder Flettner tabs appeared on Bf 109G-6s as early as 1943 with the tall tail units. The reason is obvious, to lighten forces at the higher and higher speeds these fighters began to operate at. Ie. Eric Browns mention flight with G-6/U2 with gunpods, which also had a tall tail unit with Flettner, describes the control forces as "the rudder being light, the ailerons moderately light, and the elevator extremely heavy".
Another German doc on 109G-1 manouverbility, I guess this means w/o the Rudder Flettner, notes that the "Rudder effectiveness at very high speeds is 'very good' ".
As for aileron Flettners, we know these were used, ie. for some odd reasons most German drawings of 109K show them ;) , there are also example of G-6s being so equipped. The most convincing example of them being mounted are the pictures taken in the WNF (Austria) Bf 109 paint, where they are being mounted on G-6s in a larger scale. It was a general tendency to compensate for increasing speed of the fighter, along with the appearance of Frise type ailerons of the Bf 109F, which also help to reduce ailron forces (and BTW, detailed data on ailerons of Spit I and 109E show the 109 having WAY lighter ailerons at 400mph, IIRC this was posted in the roll rate thread)
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Originally posted by VO101_Isegrim
Rudder Flettner tabs appeared on Bf 109G-6s as early as 1943 with the tall tail units. The reason is obvious, to lighten forces at the higher and higher speeds these fighters began to operate at.
Not according to Prien/Rodieke; it was from early 1944 than many G-6s were so equiped. If it was from early 1943, then that would mean right from the start of production, since the first production G-6s went to the Med in Feb 1943.
Barbi, 'rudder effectivness' has nothing to do with the force exerted by the pilot on the rudder pedal to keep the a/c flying straight. As straffo quoted for the E, a heavy foot was required at speeds above 300mph. This would have gotten worse with the more powerful engines in later 109s, at least until the Flettner tab, but even then.....
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Will have a look at the roll rate thread.
However, JQ did not seem to agree with it, and he happened to be criticizing the Spitfire's aileron control, NOT being particularly pleased with it.
Seems to me that the 109, just like the Spitfire was restlessly being improved and modified.
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Hi Kweassa,
>I'm aeronautically impaired, and have always wondered just exactly what Carson was so wrong about.
Carson's approach is to declare the Me 109 aerodynamically inferior to the Supermarine Spitfire because of the latter's lower zero-lift drag coefficient.
However, as both types historically were quite similar in their top speed, that would have required the Me 109 to compensate the higher drag with higher power.
Assuming that the Me 109 had just 10% more drag than the Spitfire, the Meesserschmitt would have needed 33% more power just to achieve the same top speed as the Spitfire (at the same altitude).
For an example, let's say both aircraft's top speed at sea level is 480 km/h.
Now what happens in manoevring combat at 240 km/h? Due to the cubic relationship mentioned above, at 1/2 of the top speed, our planes need only 1/8 of the top-speed power to overcome parasitical drag. Let's assume a Spitfire with 1000 HP and a Me 109 with 1330 HP - the Spitfire would have 875 HP excess power at 300 km/h, while the Me 109 would have 1164 HP excess power available.
This is an advantage of 289 HP which - assuming a 10% weight advantage for the Me 109 because they always were lighter than Spitfires - would translate into a climb rate advantage of about 1550 fpm.
Wow! :-) That's more like the difference between the Me 109 and the P-40 - the Spitfire compared much more favourably!
Lesson learned: Given the choice between a draggy but powerful fighter and a sleek but weak fighter, we'll always go for the drag monster :-) Obviously, the drag monster will rule at low speeds where the significance of drag greatly decreases.
I hope that explains why the Me 109 would have been greatly superior to the Spitfire in a close encounter if Carson's claim about its high drag were correct. ("Like golf scores, the lower the better, and no fudging.") As you know, the Spitfire did very well in close encounters!
The truth is, the Me 109 generally had about as much power available as the Spitfire (it changed with altitude, so it's hard to nail down), and reached about the same top speeds, too.
For the Me 109E vs. Spitfire I comparison, which I have analysed in some detail, it actually looks as if at the same power, the Me 109E should have been a bit faster than the Spitfire I. The excess power advantage accordingly resided with the Spitfire, at least at those altitudes were the Merlin could exploit the 100 octane fuel.
(Reality of course is more complex than I could describe in this space, with induced drag, exhaust thrust, propeller efficiency and everything else ... but still, as a rule of thumb - pick the drag monster :-)
Regards,
Henning (HoHun)
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Hi Crumpp,
>Eric Brown was hardly advancing an agenda other than figuring out the best tactic to shoot down Luftwaffe planes.
Eric Brown certainly did a much better job analyising the Me 109 than Carson :-) With regard to performance, I suspect the captured Me 109G wasn't quite up to par, but there is a lot of confusing data around for the Gustav series.
>Kit Carson is not wrong in his generalizations on the 109G.
Well, I hope my above analysis was a help in showing why in his central claim about the Me 109, he indeed is wrong :-)
Regards,
Henning (HoHun)
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Comparing the Spit I and 109E actually shows how little the difference was between them, and on 87 oct fuel the power was practically the same. Other factors, such as propeller design would also count.
Did the 109 have that much more drag? The Spit would however have more lift induced drag (more total lift) or what?
A Spit I with a fixed pitch or 2 pitch airscrew would be about as fast as a 109E on the 87 oct fuel, but climb less, but the Spit with a CS Screw would be slower, however climb better. Really so little difference, that just little changes will swap the cup.
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Which captured 109G? The test flight at Farnborough had multiple 109G's to choose from. In Eric Browns words "a steady diet of Me-109's". Amoung the Gustav's available were a 109G-2 and a 109G14/U4. Got pics of both in RAF colors.
Carson got his data from Farnborough. I don't see where his conclusions are wrong. Eric Brown uses the word "considerable" to describe the rudder forces in a dive on a 109, others use "seriously inconvenienced", Carson choose "a very heavy foot" and lastly the Luftwaffe used "unacceptable".
It's funny how everyone just skipped over the RLM report by Hauptmann Gollob. Gollob, who made it known he favoured the 109 before the test even started, comments on the control forces as unacceptable for the 109F4 at speeds above 700 pm/h.
Again, what is so wrong with Carson's conclusions? He wrote an article in which he generalized the aircraft's handling NOT it's production history for a PILOTS magazine. He attempted to explain WHY the 109 was obsolete by 1943 for his readers. He got the reason wrong but nonetheless the fact remains, the 109 WAS obsolete by 1943. Messerschimtt knew it, the Allies knew it, and the Luftwaffe knew it. Only one's who do not seem to know it are some folks in this forum.
Crumpp
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Originally posted by Crumpp
... the fact remains, the 109 WAS obsolete by 1943. ...
Crumpp
History has proven the design philosophy behind the 109. Maximizing Specific E with Low drag and High Power to Weight ratio is the signature for modern fighters.
Leading edge slats have also stood the test of time.
US caught on post Korea.
If the 109 was obsolete, it would not of served as a successful front line fighter the entire war vs. the allied 'non-obsolete' aircraft.
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Originally posted by Virage
If the 109 was obsolete, it would not of served as a successful front line fighter the entire war vs. the allied 'non-obsolete' aircraft.
Messerschmitt tried to design replacement a/c > the 209 and 309. Now why was that? This to me says the 109 was getting long in the tooth. The DB engine in the 190/152 would have been a better a/c.
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The 109 was no more obsolete in 1945 than the Spitfire. Both were constantly redesigned, and neither were the same planes as those that battled it out in 1940. To say that the 109 was obsolete is a fallacy.
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Again,
Only folks in this forum are holding on to the wishful fantasy the 109 was not obsolete by 1943. Even the Luftwaffe knew the truth.
Crumpp
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Originally posted by Crumpp
Which captured 109G? The test flight at Farnborough had multiple 109G's to choose from. In Eric Browns words "a steady diet of Me-109's". Amoung the Gustav's available were a 109G-2 and a 109G14/U4. Got pics of both in RAF colors.
Brown flew a 'wilde sau' Bf 109G-6 with gunpods in mid 1944, it`s clear, he also list the Wrknummer, whihc was 412 xxx IIRC (2 lazy too look it up exactly) etc. The G-2/trop you mentioned just become unairworthy just before the test were flown IIRC, not to mention it was already in rather poor condition when the British captured in late 1942.
Never heard of a G-14/U4 being flight tested by the British, it would be most interesting to see that report, if it`s not a mistake. A crashlanded G-14, most likely a converted G-6/U2 again, was examined by the Brits, but AFAIK it was not airworthy.
In fact, all the evaluations, opions are seem to root in just 3 Bf109s inspected by the British: a belly landed Bf 109E with a bent fuselage, a damaged Bf 109G-2/trop with air filter, and EB`s Bf 109G-6/U2 gunboat with 20mm gondolas.
[Carson got his data from Farnborough. I don't see where his conclusions are wrong.
Just about everywhere. Starting with the fact applying experience gained on a captured, damaged, unknown 1939 version to later, fundamentally different versions like ignoring such 'tiny' differences that the range of the 109 tripled in the meantime etc.
OK, here`s my carsonian statement. The P-51 was hopelessly outlcassed by 1944, because it had extremely poor high-altitude performance. Of course, I based my statement on the P-51A, like Carson.
Eric Brown uses the word "considerable" to describe the rudder forces in a dive on a 109, others use "seriously inconvenienced", Carson choose "a very heavy foot" and lastly the Luftwaffe used "unacceptable".
Brown says the rudder was light, period.
"The rudder is effective and if medium feel up to 300. It becomes heavier above this speed but regardless the lack of rudder trim is not a problem for the type of operations we carry out with the aeroplane. "
-Mark Hanna
Here`s another one for G-2/trop:
"The rudder force to centralise the slip ball is low, but constant rudder inputs are required during manoeuvres to minimise sideslip. If the slip ball is not kept central, the lateral force on the pilot is not uncomfortable and no handling problems occur, but it looks very untidy in a display."
-Dave Southwood.
As for Carson, he doesn`t know ***** about it, he never even seen one closeup, I bet. As for the LW saying it`s unacceptable - where?
He got the reason wrong but nonetheless the fact remains, the 109 WAS obsolete by 1943. Messerschimtt knew it, the Allies knew it, and the Luftwaffe knew it. Only one's who do not seem to know it are some folks in this forum.[
It`s not a fact, it`s a joke, and the guy who you are describing is yourself.
But if you wish, I can start posting Bf 109K performance curves vs. ANYTHING that saw combat over Europe in WW2. :D
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The 109 was about as obsolete in 1945 as other piston engine fighters......
But seriously, as a 30's design, the 109 and Spitty were really doing incredibly in 1945.
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Originally posted by Crumpp
Only folks in this forum are holding on to the wishful fantasy the 109 was not obsolete by 1943. Even the Luftwaffe knew the truth.
Crumpp [/B]
Why was it obsolate ?
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Originally posted by Angus
The 109 was about as obsolete in 1945 as other piston engine fighters......
But seriously, as a 30's design, the 109 and Spitty were really doing incredibly in 1945.
Agreed.
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How would any plane in production for a few years not be obsolete to one on paper?
It did the job, that's the bottom line.
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Originally posted by Crumpp
Again,
Only folks in this forum are holding on to the wishful fantasy the 109 was not obsolete by 1943. Even the Luftwaffe knew the truth.
Crumpp
It's a stupid post the 109 was obsolete like the 51 38 47 spit typhoon and a lot of piston fighter just because it was the start of the jet ...
In fact I wonder what is your creteria for obsolescence ?
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Hi Angus,
>Did the 109 have that much more drag? The Spit would however have more lift induced drag (more total lift) or what?
Yes, the larger wing of the Spitfire was the reason the Me 109 had slightly less drag. With regard to streamlining of fuselage, tail, radiator airflow etc., I don't think there was anything to choose between the Me 109E and the Spitfire I.
Regards,
Henning (HoHun)
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Spot on then.
The 109 would always have a higher top speed for the equal hp, for at high speeds it generates plently of lift.
The Spitty will then have an easier run and acceleration at the lower speed bands, - lower wingloading will lead to lower a of a at lower speeds, hence lower drag in that sense.
Similar they are, until they start banking and pitching, where the different wingshapes start playing a different role....
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Hi Crumpp,
>Carson got his data from Farnborough. I don't see where his conclusions are wrong.
Well, his conclusion with regard to rudder trim was:
"Consequently, at high speeds the 109 could turn far more readily to the right than to the left."
It wasn't because of this conclusion that joined the discussion :-)
You also quoted Carson with:
"But another household work, the highly propagandized Me-109G, was obsolete when it was built and was aerodynamically the most inefficient fighter of its time."
Carson's conclusion is based entirely on the Spitfire comparison which doesn't stand the test of mathematics - which is what I pointed out above.
>He attempted to explain WHY the 109 was obsolete by 1943 for his readers. He got the reason wrong but nonetheless the fact remains, the 109 WAS obsolete by 1943.
Get the reason wrong, and your conclusion is invalid. That's what happened to Carson.
(And by the way, the Me 109G came out mid-1942.)
Regards,
Henning (HoHun)
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Hi Crumpp,
>Only folks in this forum are holding on to the wishful fantasy the 109 was not obsolete by 1943. Even the Luftwaffe knew the truth.
I guess our difference mostly stems from the ambiguity of the term "obsolete".
You could well fix the date when the Me 109 became obsolete as the 15th May 1943 when Adolph Galland flew the Me 262 for the first time and immediately recommended it for series production.
The Me 262 was a leap forward - a new, ground-breaking technology incorporated into an airframe that yielding performance that in every aspect was far superior to that of the Me 109, and with superior armament, too.
However, how the Me 109 fared in combat was unaffected by the prototypes that were tested at Messerschmitt and Focke-Wulf. What determined the outcome of the air war was (besides numbers) the relative performance of the Me 109 and its opponents, such as the P-38, P-47 and P-51.
Handling qualities played a role as well, and in fact I consider the P-51 superior to all three of the other aircraft due to its viceless handling in combat. However, apart from controllability issues at high speeds - not unusual if you look at the P-38, P-47 or Spitfire -, the Me 109 handled quite well, too, and its performance certainly was up to par.
If you look at the Aces High data for the P-51D and Me 109G-10, you'd see that the Mustang is completely outclassed performance-wise below 24000 ft. Above that, the Me 109G-10 concedes the top speed advantage, but still retains a considerable climb rate advantage.
So while one might call the Me 109 "obsolete" in 1945 with some justification, it certainly stayed "competitive" in actual air combat. I'd say that only by looking at both sides of the coin, one can get an accurate picture :-)
Regards,
Henning (HoHun)
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"(And by the way, the Me 109G came out mid-1942.) "
Aye, this is the most intriguing part, I wunder, compared to what fighter of mid-1942 the high alt 109G-1 and the normal 109G-2 and F-4 would prove obsolate... ?
(Hint: They represented the very zenith of 109 performance relative to others.)
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Isegrim
The 109G-2 (werk-Nr 10639) was captured in Sicily and shipped to Liverpool on 26 December 1943 and was subsequently flown as RN228.
Brown says the Rudder Forces were "light" at cruising speeds. In a Dive they were in his words "considerable". The Luftwaffe said "unacceptable".
Eric Brown doesn't say exactly how many 109's the RAF flew. He just says a "steady diet". Sounds like more than 3. Your info on the "unflyable" 109G2 is wrong and your info on the number of 109's flown by the Enemy Aircraft Flight is probably in error also. It's all listed in the Hard Cover Second Edition Printing (1987) of Eric Brown's "Wings of the Luftwaffe". You can also see several good examples of of other captured Bf-109G-6's that the RAF flew in "Messerschmitt Bf109F-K, Development, Testing, and Production" by Willey Radinger and Woflgang Otto on page 99. All have different Werk-Nr and RAF registration numbers than the examples pictured in Brown's book. That's photographic proof of at least 3 109G-6's, 109G-2, and a 109G-14 without even digging hard.
In reference to the 109's great range being tripled.
Please explain how the 109's had such great range? Every source I have says roughly an hour flying time for a G-10 at cruising speed and about 45 minutes above cruising speed. In fact, the 109B-1 had a pitiful range of 460 Km. The 109G-10 had a range of 640 Km. I think you meant that in ten years of development they increased the 109's range by a THIRD not three times.
So show me without the use of a drop tank, how the 109's range tripled? Cause just about every plane with a drop tank has it's range doubled or tripled. That's the point of drop tanks, right? Let's use the same slide rule.
Definition of Obsolete IMO.
I define a fighter being obsolete when equal pilots cannot achieve a victory. By 1944 only the experten had a chance to survive going one on one with your average trained allied pilot. If you do not have a technological parity then one of you is flying an obsolete plane for the fight. The 109 was that plane after 1943.
Put in the mix in a Target rich enviroment and sure some are gonna score. Especially when the fight occurs in the 109G's "best performance" zone above 25,000 feet.
Hohun,
the discussion was on the rudder forces of the 109 NOT on it's drag coefficient. In the end it is your conclusions that matter NOT how you arrived at them. Just look at the Theory of Relativity or Antenna Theory. Quite a few holes in them, yet we still got the Atom Bomb and can talk on our cell phones. In that light Carson's conclusion's are valid.
When you refer to "prototype" testing at Messerschmitt and Focke-Wulf are you refering to Beauvais and Gollob's test flight? In that test the planes flown were an FW-190A2 (no Umrustsatz or Rustsatz kits, just the Air Superiority fighter version) and a Bf-109F4 (no Umrustsatz or Rustsatz, just the Air Superiority fighter version). both Aircraft were configured with full internal fuel and full combat ammo loads.
Crumpp
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Originally posted by Crumpp
I define a fighter being obsolete when equal pilots cannot achieve a victory. By 1944 only the experten had a chance to survive going one on one with your average trained allied pilot.
The 109 and Spitfire are equal or superior in combat to any US fighter at any specific time in WWII. The US fighters were great strategic fighters, but sacrificed some performance to achieve range. The 109 and Spitfire were "fighter fighters" to quote Yeager (IIRC). Your comparison is ridiculous considering in 1944 the LW was hopelessly outnumbered and ordered to avoid allied fighters to get to the bombers. The fact that the Experten managed not only to survive, but to claim an astonishing number of victories in 109s under those circumstances is a testament to the 109s performance.
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Numbers are one vs one and it's explained in the text so break out your dictionary and read it. Since English is your second language your excused.
Sorry, Gsholz as much as you admire your former conquerers, the 109 was obsolete by 1943, at least according to Generalleutenant Galland and Generaleutenant Schmid.
Crumpp
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How do you justify your claim that 1 on 1 the 109 couldn't survive against an allied fighter, both with equally skilled pilots and equal advantage?
And btw. your ignorance is showing. The 109's "best performance" zone was not above 25k.
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(http://www.onpoi.net/ah/pics/users/245_1084412068_109g10-p51dspeed.jpg)
(http://www.onpoi.net/ah/pics/users/245_1084412131_109g10-p51dclimb.jpg)
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It's not my ignorance, it is Eric Brown's quote. I am leaning toward believing him over you.
No one is claiming the 109G10 didn't have a good climb rate and good speed. Read the rest of the thread and you will figure it out.
To be an effective fighter you need more than just that. If the control forces above 440 kph are "unacceptable" as Gollob worded it then it does you no good to fly in a straight line really fast up high.
If your plane does not turn well you have to fight in the vertical. If you do not maneuver well as high speeds then your fighter is not very effective in a vertical attack were high speed passes and zoom climbs are the order of the day.
Seemed pretty common sense to me, so I spelled it out for you Gscholtz.
Crumpp
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Put in the mix in a Target rich enviroment and sure some are gonna score. Especially when the fight occurs in the 109G's "best performance" zone above 25,000 feet.
You dont know wth you are talking about.
You are just as ignorant in this thread as you were in the BoB thread.
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BTW
Pretty graphs, but what is the source? AH? WB? Your paintshop pro files?
Crumpp
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Originally posted by Crumpp
BTW
Pretty graphs, but what is the source? AH? WB? Your paintshop pro files?
Crumpp
They are all lies!!!! Only Carson knows the truth!!!
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Erich Hartmann's first kill was in Nov '42. His second kill was 3 month's later.
Obsolete plane?
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Just like the Bob thread,
Your resorting to name calling when you run out of facts Batz!
Get a life.
Crumpp
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Hi Crumpp,
>Definition of Obsolete IMO.
>I define a fighter being obsolete when equal pilots cannot achieve a victory. By 1944 only the experten had a chance to survive going one on one with your average trained allied pilot.
Try to prove that :-)
According to objective parameters, the Me 109 was still highly competitive:
Me 109G-10 performance:
http://www.hitechcreations.com/ahhelp/models/109g10.html
P-51D performance:
http://www.hitechcreations.com/ahhelp/models/p51d.html
As you can see, below 25000 ft the Me 109G-10 is considerably superior to the P-51D. Above 25000 ft, the Me 109G-10 holds the climb advantage and the P-51D the speed advantage.
>the discussion was on the rudder forces of the 109 NOT on it's drag coefficient.
You quoted Carson's overall verdict on the Me 109, so it was you who expanded the discussion.
>In the end it is your conclusions that matter NOT how you arrived at them.
LOL! So if I rolled the dice to determine which aircraft was superior, my conclusion would be valid, too, because only the results count? ;-)
>When you refer to "prototype" testing at Messerschmitt and Focke-Wulf are you refering to Beauvais and Gollob's test flight?
No, I'm referring to Me 262 and Fw 190/DB603 testing. The Fw 190A was excellent, but it wasn't as good as the Me 109F in some areas of performance, for example climb rate.
Regards,
Henning (HoHun)
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Hi Crumpp,
>To be an effective fighter you need more than just that. If the control forces above 440 kph are "unacceptable" as Gollob worded it then it does you no good to fly in a straight line really fast up high.
Well, since you quoted "700" above, I guess that was km/h and "440" is in fact mph.
Let me point out that you seem to be neglecting the difference between true and indicated airspeed.
Control forces depended on indicated airspeed, so if 700 km/h are quoted, you're actually talking about for example 903 km/h @ 5 km altitude, and even more if you go higher.
The Me 109 was far from being restricting to "flying in a straight line really fast up high" because really fast up high translated into low indicated airspeeds, and the Me 109's manoevrability at low indicated airspeeds was rather good. At 30000 ft, 440 mph TAS are only 270 mph IAS.
Of course, the Me 109G-10's good power-to-weight ratio greatly helped its manoevrability at high altitude, too.
Regards,
Henning (HoHun)
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Well, Crumpp is basically referring to really high speeds, where the 109 was definatley "heavier" than the U.S. Fighters in particular, so I get his point there.
The 109 in combat had two things in its favour, which helped its pilots to rack up so impressive kill numbers
Firstly: Situation. Plenty of targets, and due to that, the engagements were often only executed under favourable conditions. Hit and getaway, - typically diving away after a pass, or if things went bad.
However, on the western front in 1943/44, it could not count on that any more.
Secondly: Speed. The 109 was always about as fast as the fastest planes the enemy could mount. It enjoyed speed superiority over enemy fighters for long times in many theaters. That is a pure and undisputable fact.
So, up-to-date with everything, perhaps not. But definately not that obsolete.....
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I know the differenece between IAS and TAS. I fly a real plane on occasion.
I did mean MPH not kph. The RLM test said 700 kph.
Nice data, but we are talking about the real plane not some games version. All the sources I have including flight graphs from the RLM of the 109G with DB-605D AND GM-1 put the max top speed between 685-695 Km/h. That's quite a bit slower than the P51D.
Since I fly only LW A/C it's nice to know that AH HAS in fact thrown us a bone.
Crumpp
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IMHO the AH 109 is just pretty ok
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Originally posted by Virage
Erich Hartmann's first kill was in Nov '42. His second kill was 3 month's later.
Obsolete plane?
Would you say the I-153 bi-plane was obsolete?
Wunder of wunders, it was still being used into 1943and still having some success.:eek:
Would you say the He112 was obsolete?
Again, wunder of wunders, in March 1943, a Spanish He112 damaged a 14thFG P-38.:eek:
It would seem they are not obsolete because they were still having success in the air, using your definition.
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Some of you are pretty dense. No where in my definition of Obsolete MiloMoran does it say anything about the plane not having some success. In fact I point out in a target rich enviroment such as the Luftwaffe struggled on in 1944 it would not be amazing for an expert pilot to rack up kills.
Let me reword it for you without the "big words" you didn't look up so It's easier to understand:
If the pilots are equal and the performance of their equipment is not, then the equipment is obsolete.
It's a tough concept to wrap your mind around, especially when there are many different parameters in measuring plane performance that can be critical in a fight.
Especially if they followed Hartmanns techniques and avoided DOGFIGHTING and stuck to See, decide, attack, coffe break, style he perfected. Hartmann felt that mixing it up was stupid and strived to "ambush" his victims. It's well documented. Do a little research and you will see it.
Crumpp
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Originally posted by Crumpp
Nice data, but we are talking about the real plane not some games version. All the sources I have including flight graphs from the RLM of the 109G with DB-605D AND GM-1 put the max top speed between 685-695 Km/h. That's quite a bit slower than the P51D.
Crumpp
UHm, thats a pretty good example of your heavily lacking knowladge on the subject you desperately want to force through.
Things like:
a, Bf 109G-10 never used GM 1
b, G-10 max. performance was 695 km/h 6000 to 7500m. K-4 did 715 km/h at the same altitudes. The P-54D could manage 698. Quite a bit slower...? Of course max. speed is rather irrevleant, the fact that late Bf 109s enjoyed MARKED RoC advantage (4500-4900 fpm vs. 3400 of the P-51D), and even more marked, nearly double to level acceleration advantage weighted a lot more in air combat.
As for your maximum range comments, I guess the the increase from 460 miles range of the Bf 109E to 1200 miles on the Bf 109G with six hours of endurance does counts as triple range.. Later 109Gs and esp the 109K had even better range. There were even longer ranged recce 109Gs, but those are not listed here, even though 1800-2000 miles range for them seems reasonable for them with their two droptanks.
As for your range specs, they refer to range at the highest cruising speed, not economical flying for which other a/c specs are listed for.
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Somewhere on my HD I have a very good tale of Hartmann outfighting a P51 1 vs 1.
Rall also warmed up some US planes in dogfights...
Crumpp, you seem to be overly aware of the fact that some of us here don't have English as a 1st language, however I will have to debate you on the word "obsolete" in the term you defined it.
"If the pilots are equal and the performance of their equipment is not, then the equipment is obsolete. "
You should rather use "inferior", or "less suited to the task" IMHO. And then you hit another fact. Performance.
In 1945 the 109 was being used as a quick interceptor, thus modified for the role. In the design of an aircraft, one has to bear in mind that there is no free lunch (as J.Quill put it), - developing an aircraft into one direction will never be without sacrifice. Some US planes have some way to go in terms of say, low speed maneuverability, or performance at some altitude bands, and the 109 was not perfect either. But at what it was applied for late in WW2, it did pretty good. Fast-climbing relatively nimble interceptor, and as such, even in 1945, it was excellent. Find anything that can outsport the 109K in getting it and its armament to 20K in 4.5 minutes. Well, nothing, except perhaps the current Spitfire. Find anything with as easy and simple maintenance as the 109 in WW2, - well, I guess nothing (but this is not very much discussed)
Anyway, the 109 was in my definition not obsolete at the end of WW2. It wasn't the king any more, but not obsolete.
The Hurricane was obsolete. the F4F was. The P-40 was, and so was the I-16. But IMHO the 109 was NOT.
P.S. I don't think I can be described as a 109 fan, - ask Barbi :D
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Ahh, about the range thingie.
The 109 always had short legs, on internal.
Haggling about range with DT's is just silly, - once in combat they would have to be dropped.
The only true single engined long ranged fighter of WW2 was the P51, only comparable with PR planes and late-late Spitties.
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Originally posted by Crumpp
Some of you are pretty dense. No where in my definition of Obsolete MiloMoran does it say anything about the plane not having some success. In fact I point out in a target rich enviroment such as the Luftwaffe struggled on in 1944 it would not be amazing for an expert pilot to rack up kills.
Let me reword it for you without the "big words" you didn't look up so It's easier to understand:
If the pilots are equal and the performance of their equipment is not, then the equipment is obsolete.
It's a tough concept to wrap your mind around, especially when there are many different parameters in measuring plane performance that can be critical in a fight.
Especially if they followed Hartmanns techniques and avoided DOGFIGHTING and stuck to See, decide, attack, coffe break, style he perfected. Hartmann felt that mixing it up was stupid and strived to "ambush" his victims. It's well documented. Do a little research and you will see it.
Crumpp
:rofl :rofl :rofl
Well I see, as other are saying, that the Crumpite has reading problems and is an prettythanghat. Where in my post do you see your name. I was quoting Virage. At least some of have some matter between the ears which you are lacking. So sweet little Crumpite, would like to see an apoligy for your uncalled for words.
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OIII
come on guys....cool it a little
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Originally posted by Angus
Ahh, about the range thingie.
The 109 always had short legs, on internal.
Haggling about range with DT's is just silly, - once in combat they would have to be dropped.
The only true single engined long ranged fighter of WW2 was the P51, only comparable with PR planes and late-late Spitties.
Recalling from memory of the G-2/trop papers Neil kindly provided, IIRC on internal 400 liter tank the range was something like 700 miles or so. High altitude versions would develop higher speeds at higher altitudes with similiar or less fuel consumped, so I guess there could be even a marked increase in range with them in 1944. 109K also introduced a DP rear tank, which could be used as a extra fuel tank for 25% more internal capacity, if needed (MW50 could not be carried though).
IMHO, thats more than enough for any purpose this plane was used, including escorting the German medium bombers over Russia etc. It was enough to fight rather deep in enemy territory and then return, after the DT was droppen when engaging the enemy, or cruise over Germany for hours to build up a formation, plan the attack until the enemy bombers arrived. Not the longest ranged, but good enough to fullfill any task the LW would face.
As for late Spitties, the range remained very much like 450-460 miles on internal, and roughly 1000 miles w the 90 gallon droptank. Increasing internal fuel only managed to satisfy the growings thirst of Merlins and Griffons. The PR Spits were really long range, with much increased internal capacity and loaded to the maximum w. extra droptanks, but they were kind of special, unarmed breed, not fighters. The Spitty remained very much the same thing as it was developed for, at least the versions during the war, a short ranged defender of the air over the British Isles and their direct vicinity, much more a 'pure' interceptor than the Bf 109 which had to fill muliple tasks on 3 rather different fronts.
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Originally posted by Angus
OIII
come on guys....cool it a little
Angus, I be kewl.:) Crumpite just gave me a good chuckle to go with my morning coffee and it is a beautiful day out there.:aok Think I will not work today and go for couple hundred mile, or so, mc ride.
Barbi, during the last year of the war, Germany was a battle zone. Any a/c cruising along at a speed to conserve fuel would be a sitting duck. Just like the Spit did with the 190, a high speed would be used to give some safety. This uses more fuel.
The Spit had to fly in different fronts. ETO, MTO, CBI, SWP, and at sea from carriers. Rather diverse theatres.
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Spit 24: roughly 1400 miles
Spit XVIII: the same, however not a popular model
Spit IX mods, both English and US: To Berlin and back at rather high speed under 1000 ft, and over the Atlantic over Greenland and Iceland.
I recall some more data, just can't find it in a hurry :(
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Hm... well, I'm pretty sure that the germans would have been a lot happier with a type which could have carried at least three cannons and fuel for 2h (at practical power setting for climb and fight at say 30k) without sacrificing performance, maneuverability and tactical freedom (as in the case of the Bf 109 with wing cannons and extra fuel).
But this has been discused here several times, no consensus so far....
gripen
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MiloMorai,
Sorry bout that. I skimmed through your post and misunderstood it. Please accept my apology.
As to the DB-605D with GM-1. It's clearly marked on an RLM test flight graph. I'll post it if I can when I get to the house.
Crumpp
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Crumpp, believe what you will. It doesn't matter one bit.
>>>
Guys, please don't turn this into another 109 vs. Spit thread. Both were great fighters in their own way.
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Originally posted by HoHun
Me 109G-10 performance:
http://www.hitechcreations.com/ahhelp/models/109g10.html
P-51D performance:
http://www.hitechcreations.com/ahhelp/models/p51d.html
As you can see, below 25000 ft the Me 109G-10 is considerably superior to the P-51D. Above 25000 ft, the Me 109G-10 holds the climb advantage and the P-51D the speed advantage.
The charts I posted earlier are HTC's too, I just superimposed them on one another for easy comparison (I have done this on most planes vs. my favourite planes as a reference in fights). As you can see the 109G10 holds the speed advantage at any altitude except at SL where the P-51D is slightly faster. Above 25k the 109's speed advantage is marginal however.
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P51B/C is faster than the D.
A 109 G10 would not be the typical opponent, rather the 109G6.
I'd take the Mustang.
None the less, the 109 in tha co-P51 situation is absolutely not obsolete.....
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"Our" G6 is a 1943 model. A 1944 model G6 would have better performance, and would match up pretty well to a Mustang. The P-51B/C is indeed faster than the D, however only very high up close to 30k and beyond. At low-med altitude the B/C is slower than the D. The D is also the better climber at all altitudes, so the B/C would be even more at a disadvantage in the vertical against a 109.
However this is all relative ... it all comes down to the pilot and luck.
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Originally posted by Crumpp
MiloMorai,
Sorry bout that. I skimmed through your post and misunderstood it. Please accept my apology.
Crumpp
All's well that ends well, so NP. accepted :)
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All these comparatives about top speeds and who is faster than who are worthless. Acceleration/E retention can dictate a dogfight, top speed cant. And before getting into a "who turns better than who" battle, take into cosideration that hurricanes outturn easily any gustav, but any gustav will eat alive any hurricane. IMO, turning, as top speed are both secondary factors. Based on acceleration and climbing, 109 was certainly a killer for any 1 vs 1 encounter at most alts, I wouldnt consider that an outclassed fighter.
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Ok I need a little help in posting the image. Could somebody give me a quick tutorial on this bulletin board. What do I have to do? Save the image as a web page and hyperlink it? WTF??
All the DB605D's in the RLM test data I have are fitted with GM-1. Only the DB605L uses MW50 in these documents.
It does state in "Messerschmitt Bf 109 F, G, and K Series : An Illustrated Study" by Jochen Prien and Peter Rodeike that the 109G10's were fitted in every instance with a DB605DM.
It also says the 109G10 was an attempt to bring older varients of the 109 up to 109K standards and that many retained much of their original equipment. Most of us already know that. It was a "bastard aircraft" and impossible to standardize. The 109G-6 was outfitted with GM-1 is some cases and I have to wonder if they just didn't hook up the GM-1 system to the DB-605D and send the plane out of the factory door?
Crumpp
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Go here and upload the picture (create a user first). Then link the picture to your post using the IMG button.
http://www.onpoi.net/ah/index.php
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Some of you guys are still confusing the Game modeling with the actual performance. NONE of the reference material I have list's the 109G10's top speed as high as AH has it modeled.
Someone please show me where the 109G10 (the real one) was that fast.
Crumpp
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Isegrim will be here any minute. ;) ... but I bet HiTech has those.
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Lots of performance graphs in this PDF file Crummp.
http://mitglied.lycos.de/luftwaffe1/aircraft/lw/109_projekt.pdf
DB605 data (scans not the best) here
http://mitglied.lycos.de/luftwaffe1/aircraft/lw/DB605_varianten.pdf
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Here is the Graph,
(http://DB605Dgraph)
Crumpp
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Nevermind,
Milo posted the graph...refer to his link.
Crumpp
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IIRC The AH G10 has the performance of C3 fuel and 1.98 ata.
in March 1945 only two units of the Luftflotte 6 both equipped with G-10 were using C3, one being IV/JG 4 the other being II/JG 11, and no K-4 units at all.
1.98ata was cleared in Feb 45.
In fact the default paint scheme of the AH G10 is that of Hptm. Franz Wienhusen IV./JG 4.
Crumpp no one has to prove anything to you and HT isn’t going to show you his data. It really doesn’t matter whether you ever see it or not. It’s clear from your reliance on Carson that you wouldn't really understand what you were reading any way.
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For your information Crumpp, the AH 109G10 has the DB605DC engine with MW50. It has been said that we have the best possible version of the "bastard" G10 ... almost a K4.
Here is the engine specs of the DB605DC ... it's a 2000PS engine with MW50 (I have the complete PDF of all DB605s if you're interested Edit: NM, Milo posted the complete pdf.).
http://www.onpoi.net/ah/pics/users/245_1084492281_pages_from_db605_varianten-2.zip
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If the 109 was a competative fighter Why did HT feel the need to model a varient that saw such little use?
Why don't we have a much more common model late war 109?
Crumpp
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All the 109s in AH are competitive, I only fly the G-6 and kill far more late war monster then ever could kill me...
So whats your point? I think the G6 is the best 109 in AH....
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*lol* I mostly flew the 1941 F4 model in AH with a 5 to 1 k/d. I'm considering picking up a G2 in AH2.
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Niether the 109G-2 nor the F4 were late war 109's. No one is claiming the early-mid war 109's were obsolete. Again why do we have such an uncommon late war varient IF the more common ones were competative?
Crumpp
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Because HT and Pyro were trying to avoid using the same planes as WB had in the early days of AH. Instead of giving the Bf109K-4 as the "final version" of 109s, they've decided to use the G-10 with the DB605DCM instead.
The decision to use an "uncommon" 109 has nothing common with your implications: it was just because the developers wanted to do something else than the usual K-4, so naturally they picked the last Gustav of them all, which was pretty close to the K-4 in performance.
..
And just exactly in what ways is the late war 109s "obsolete"?
You seem to be arguing the same things over and over again, except I've yet to see any specific comparisons in speed, agility, climb, acceleration or anything other attribute that might be considered viable determining whether a plane is obsolete or not.
Just what exactly are the grounds that you're implying it was "obsolete"?
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What difference does it make what variant of 109 HT models? Unless you are claiming HT modelled the "best" G-10 for AH because its the only one that would be competitive. If that's the case both GS and I are telling (and which you can varify) all the 109s in AH are very competitive.
Also, why wouldn't HT model the E-4 with a DB601N? or a g14 instead of the g6? or g1 with gm1 instead of the g2?
So again what's your point?
Maybe he thought he could add a G10 that could sub as a K-4 that way creating a "unique" planeset for AH while filling gaps in the planeset? It could be any 1 of 1000 reasons, so who cares?
We have plenty of "uncommon" variants of all sorts in AH...
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Read the thread Kweassa I'm not rehashing it.
The 109 was obsolete according to the Luftwaffe by 1943. They didn't have anything to replace it so they had to soldier on til something better came about.
That is a fact.
Crumpp
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The G-10 in AH is basically a K-4. The reason the G-10 was chosen over the K-4 is because the K-4 had standardized the armament to the MK 108 while the G-10 allows you the choice between that and the MG 151/20.
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All there is some measly comment on how "the controls stiffen at certain speeds, and how that must obviously mean the 109 was obsolete" - yet even up to the last days of war planes having serious problems at high speeds was the norm, and planes that didn't have much trouble were still rather few. Heck even the P-47 and P-51 had troubles with high speeds.
Besides that single point you refuse to acknowledge speed, maneuverability, climb, acceleration, and a various many factors without any reason, evidently.
Crumpp, you don't have anything to rehash, because you never gave us anything conclusive, or that makes sense, up to date.
So I URGE[/i] you to pick out just exactly what kind of attributes a fighter must have, and which of them the 109 was exactly "obsolete" in. It's a long thread. If you are really so confident than it shouldn't be too hard to briefly summarize your point.
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Another point to check about obsolescence is the industrial tooling and cost.
The industrial process for the 109 was known and mastered (plus the 109 was pretty ahead in term on industrial process even in the early war version) it was from a industrial POV pretty well designed and didn't cost a lot to be produced compared to some other German planes.
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Hi Crumpp,
>I know the differenece between IAS and TAS. I fly a real plane on occasion.
Well, you seem to miss its tactical significance, though. At high altitude, the indicated air speeds at which the Me 109 was control force limited simply couldn't be achieved. The limitation was the Mach number, and that's an aspect were the Me 109 was fairly good. It could go to Mach 0.79, far beyond what the P-38 or the P-47 could achieve, though the Spitfire was still better.
>Nice data, but we are talking about the real plane not some games version. All the sources I have including flight graphs from the RLM of the 109G with DB-605D AND GM-1 put the max top speed between 685-695 Km/h.
Those graphs are mostly early 1944 Messerschmitt calculations, not RLM flight test data. Many of them are for MIL, not for WEP. I'm quite confident the Aces High team has done some quality research, though :-)
Regards,
Henning (HoHun)
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Hi Crumpp,
>If the pilots are equal and the performance of their equipment is not, then the equipment is obsolete.
By that definition, the Me 109 indeed was NOT obsolete since its performance compared quite well to the P-51's.
The Me 109 held the climb advantage, and any version with MW50 injection also held the speed advantage at low and medium altitudes.
If the P-51D high-altitude speed was superior as you claimed, which I'm quite ready to assume for the sake of the comparison, this still left the Me 109 with the climb and acceleration advantage up high.
Due to its better power loading, it just had the better specific excess power so it could gain an energy advantage on the Mustang quite easily.
In a "target-rich environment" - which is just a great euphemism for being heavily outnumbered - the Me 109's climb rate advantage was quite useful because it meant that it could get above the enemy formations in a rather short time, and of course it helps your competitiveness if you bring extra altitude into the fight :-)
In short, the Me 109 was only inferior in performance in some regards to the P-51, and superior in others. By your own definition, that means it just as much or as little obsolete as the P-51 itself.
Regards,
Henning (HoHun)
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Hi Crumpp,
>The 109 was obsolete according to the Luftwaffe by 1943.
Which definition did the Luftwaffe use as basis for their 1943 statement?
As I pointed out, Galland demanded a superior fighter, not merely an equal one, in 1943.
The new fighters the German aircraft manufacturers were preparing would have been superior, if they had been ready in time. (Mostly, they delayed because the required engines were well behind schedule.)
Regards,
Henning (HoHun)
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Hi Crumpp,
>Again why do we have such an uncommon late war varient IF the more common ones were competative?
Well, this almost sounds as if you're ready to concede that the Me 109G-10 is competitive :-)
In that case, your entire case would crumbble because it proves the competitiveness of the airframe.
Remember: "Me 109" is just the designation for the airframe.
If all you need to do is to mount a powerful late-war engine to an existing airframe to make it competitive again, it wasn't the airframe that was obsolete, it was the engine.
Not that I'd agree that the DB605 was obsolete, but it certainly would be a more intelligent hypothesis to begin with than Carson's old "Me 109 obsolete" myth :-)
Regards,
Henning (HoHun)
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Hi Kweassa,
>So I URGE[/i] you to pick out just exactly what kind of attributes a fighter must have, and which of them the 109 was exactly "obsolete" in. It's a long thread. If you are really so confident than it shouldn't be too hard to briefly summarize your point.
Very good point :-)
In fact, it might be a good idea to devise a fighter A vs. fighter B comparison matrix based on rational, factual parameters that gives us a relative score saying something like "fighter A was 18.2% better than fighter B".
Not that I really believe it would accurately reflect history, but the learning effect from devising such a matrix would be great, and we could use it to break dead-locked threads by saying "At least, the Rational Fighter Comparison says ..." :-) If then someone still disagreed with the result, he could point out exactly where he thought the matrix gave the wrong score ...
Regards,
Henning (HoHun)
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From HoHun:
"Well, you seem to miss its tactical significance, though. At high altitude, the indicated air speeds at which the Me 109 was control force limited simply couldn't be achieved. The limitation was the Mach number, and that's an aspect were the Me 109 was fairly good. It could go to Mach 0.79, far beyond what the P-38 or the P-47 could achieve, though the Spitfire was still better. "
In a screaming dive the 109 would be able to pull away from most allied planes, - for a while.
In the dive, the 109 was sluggish, - the P47 could still roll. Levelling out of the dive, the P47 would still be really close to the 109.
Since a typical engagement of say 109 vs bombers covered with escorts would be a diving pass, the P47 or the P51 as an escort was a nightmare to the 109.
Not that it made the 109 obsolete......
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Originally posted by Batz
All the 109s in AH are competitive, I only fly the G-6 and kill far more late war monster then ever could kill me...
So whats your point? I think the G6 is the best 109 in AH....
Originally posted by GScholz
*lol* I mostly flew the 1941 F4 model in AH with a 5 to 1 k/d. I'm considering picking up a G2 in AH2.
Originally posted by Crumpp
Niether the 109G-2 nor the F4 were late war 109's. No one is claiming the early-mid war 109's were obsolete.
This must be the greatest argument ever posted in this forum *lol*. I suppose the Germans should have just stopped with the F4 and G2 since they were not obsolete ... I mean, how dumb were they ... developing those obsolete 109s when they already had competitive ones?! *LOL!*
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What a moronic (it means really stupid GSholtz) statement. Guess you have never owned a watch and noticed the hands move in a clockwise fashion.
Time marches on......Things change. With your logic the BundesLuftwaffe should still be flying 109's!!!!!
Crumpp
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No, you didn't get the irony I guess. Batz stated he was very successful in the 109G6 against late-war planes, and most of my kills in the 109F4 are late-war rides. My k/d in the 109G10 is better than in the F4, but I just enjoy fighting in it more.
AH is only a game, but it is created by a company that takes great pride in accuracy. When 109F4s, G2s and G6s are successful against late war rides like P-51s, P-38Ls, La-7s etc. it says something about the performance of the plane. The 109G10 has the ability to dominate every fight. Same with the 190D9 and Ta-152 ... there were just too few of them with too few trained pilots to fly them.
Unless you are arguing that the performance of the late war 109s were WORSE than the F4 and G2, then logic demands that the 109 was indeed a competitive fighter in 1944 and 1945.
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Well, errr...I also killed a Spit XIV with a Spit I, as well as other 5 planes and landed 14 perks after a 20 minute flight, but.....
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Yes?
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I've shot down Shane in my F4 (he in his La-7). It was an "arranged" fight in the MA.
... felt rather good about that actually. ;)
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Yawn
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Hey Crumpp,
>Yawn
Get the sleep out of your eyes and answer the following posts, please :-)
HoHun 05-14-2004 08:21 AM
HoHun 05-14-2004 08:38 AM
HoHun 05-14-2004 08:45 AM
HoHun 05-14-2004 08:55 AM
Regards,
Henning (HoHun)
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Originally posted by Crumpp
Some of you guys are still confusing the Game modeling with the actual performance. NONE of the reference material I have list's the 109G10's top speed as high as AH has it modeled.
Crumpp
.. and what reference material would that be ?
Have to agree with Kweassa, until you really tell us why exactly was the Bf 109 'obsolate' by 1943, I don`t think there would be much need to argue.
As for the rest:
"It does state in "Messerschmitt Bf 109 F, G, and K Series : An Illustrated Study" by Jochen Prien and Peter Rodeike that the 109G10's were fitted in every instance with a DB605DM. "
ad1, It does not, DM was fitted to the early G-10s, there`s factual evidence of 605DCO etc. being fitted to G-10s that were examined.
As well as there`s no sign of any indication of GM-1 ever being used on Bf 109s with large compressors, the increased altitude performance of the engine made it unneccesary; it would be dead weight under 10 000m or so, practically 99.9% of the combat time.
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That's about a stupid statement Isegrim. Go look at the performance charts posted above. It clearly states DB605 with GM-1.
The book you and I are quoting is by some of the most respected 109 authorities around. They will tell you that 109G10's are not standardized.
Say something else Isegrim, Please!
:aok
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As far as the late war 109's being obsolete. I have already covered that. With their control forces and manuverability problems at high speed the effectiveness of the plane for your average trained pilot placed in an ineffective status.
You ever read "Flight Journal's Magazines" WWII fighter edition? Gunther Rall advises the pilot NOT to fly the plane unless he has a factory trained mechanic check out the brakes. Here is a guy who just gonna take a hop around the airfield in it. 1/3 of the 109's manufactured were lost in landing and takeoff accidents! The plane had some horrible characteristics.
I'm not talking about the planes usefulness in AH nor about mid war and earlier varients. We have a rare very late war varient of the 109G10 that is a 109K for all practical purposes. The 109 did maintain some advantages throughout is lifecycle in WWII. It did pioneer some avaition firsts and deserves to be listed amount the great fighters of the world. However you had to be a really really good pilot to take advantage of them by 1944 and to most pilots the planes bad characteristics outweighed it's good ones.
It became sort of like a Sniper rifle. A very useful weapon. In the right hands a Sniper Rifle can engage targets faster and at longer ranges than a Machine Gun AND still remain hidden from enemy observation. However the average rifleman cannot engage targets at 400 meters and beyond with it. Give him a Machine Gun with some tracer ammo and he will hit the target after a few burst's.
Is a Sniper rifle obsolete? No, not in the specialized catagory it is used in. Would it be obsolete as a primary weapon for your infantry soldier? Of Course. Your army would be back to WWI carrying bolt action rifles.
The 109 as the primary weapon for the single engine dayfighter pilots was obsolete after 1943 just as the Luftwaffe says.
Crumpp
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That's about a stupid statement Isegrim. Go look at the performance charts posted above. It clearly states DB605 with GM-1.
Hohun already answered. To sum it up that's a "what-if" chart, drawn from calculations of how a 109 with a DB605 would perform IF, it was ever equipped with a GM-1.
You ever read "Flight Journal's Magazines" WWII fighter edition? Gunther Rall advises the pilot NOT to fly the plane unless he has a factory trained mechanic check out the brakes. Here is a guy who just gonna take a hop around the airfield in it. 1/3 of the 109's manufactured were lost in landing and takeoff accidents! The plane had some horrible characteristics.
You're saying 33% of some 35,000 aircraft produced, some 11 thousand 109s were lost in take-off and landing accidents alone? That's really funny, cause the last time I checked, it was more like 5% - which was more or less the typical number for any plane of that time.
We have a rare very late war varient of the 109G10 that is a 109K for all practical purposes.
Both the Bf109G-10 and the Bf109K-4 is a 1944 plane. Nor were they "rare". By your definition of "very late war" the P-51B and the P-51D also falls under the category, and should not be used in comparison.
The 109 did maintain some advantages throughout is lifecycle in WWII. It did pioneer some avaition firsts and deserves to be listed amount the great fighters of the world. However you had to be a really really good pilot to take advantage of them by 1944 and to most pilots the planes bad characteristics outweighed it's good ones.
Like, which characteristics? And what's your standards for this alleged "measurement of weight"?
Is a Sniper rifle obsolete? No, not in the specialized catagory it is used in. Would it be obsolete as a primary weapon for your infantry soldier? Of Course. Your army would be back to WWI carrying bolt action rifles.
By doing this, you are effectively denouncing the worth of every attribute a certain plane holds, and crunching them into a singular comparison which standards are totally out of context and order. It's elaborate, but meaningless.
The 109 as the primary weapon for the single engine dayfighter pilots was obsolete after 1943 just as the Luftwaffe says.
Just like the P-38 and P-47 was totally obsolete as an important fighter of the war in the latter days, right?
Or how about this?
According to your agenda of a "general purpose fighter" being the most important thing of them all, and all other "special purposes(as in your 'sniper rifle' comparison)" are to be considered "obsolete", then clearly the P-51D is also a pretty obsolete plane.
As a standard "fighter", for air-superiority purposes, the Spitfire Mk.14 is clearly a superior fighter - combining some best of characteristics of both the 109 and the P-51D. Fast, sleek, lightweight, good armament, good climb, good maneuverability, fair handling at high speeds, good performance at high altitudes. good visibility.. you name it.
So by 1944, the USAAF started using a clearly obsolete plane as a pure "fighter", an Air-to-Air superiority aircraft, but still had no choice as the P-51D was the only thing that flew that long, right? Just like the LW had no choice but to use a clearly obsolete fighter as a point-defense interceptor?
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Originally posted by Crumpp
As far as the late war 109's being obsolete. I have already covered that. With their control forces and manuverability problems at high speed the effectiveness of the plane for your average trained pilot placed in an ineffective status.
The Bf 109 did not have any seriously restrictive problems despite you suggest that and fail to back up. Neither because the reasons HoHun has pointed out, neither because its high speed controls werent worser than the avarage, in fact they were better than many.
1/3 of the 109's manufactured were lost in landing and takeoff accidents! The plane had some horrible characteristics.
Thats a BS number. 33%? Why isn`t it reflected in any LW loss report, why the type`s combat/non-combat losses differe very little from the FW 190?
Ask any Bf 109 pilot and they will tell you it was one of the most benign, pilot friendly planes once in the air. Takeoff and landing has to be treated with respect, true, nothing sort of surprising with such a high power s-e fighter of the time.
[I'm not talking about the planes usefulness in AH nor about mid war and earlier varients. We have a rare very late war varient of the 109G10 that is a 109K for all practical purposes.
2600 G-10s were produced.
~1800 or so, equivalent performer G-14/AS and G-6/AS were produced.
1700 K-4s were produced.
That`s a LOT, not rare...
LW records show 60% of the Bf 109s being G-14/AS, G-10, or K-4 type by end of Jan 1945. Rare...?
314, or 25% of them alone were K-4s. Neither very-very late, they saw service first in October 1944, 200 already, few months after P-51D.
However you had to be a really really good pilot to take advantage of them by 1944 and to most pilots the planes bad characteristics outweighed it's good ones.
Yeah like 90% automated eninge controls, good armor protection, very benign stall charactericstics and handling, great manouveribility in dogfight, unsurprassed climb rates, excellent dive and zoom charachteristics, short take off run, and probably the best acceleration of any WW2 fighter, good sighting view, simple controls, simple maintaince, repair, and production, powerful cannon armament etc.
Bad characteristics? Tendency to ground loop if not handled correctly, higher than avarage elevator forces - equivalent of that of the P-51 BTW.. That`s all.
The 109 as the primary weapon for the single engine dayfighter pilots was obsolete after 1943 just as the Luftwaffe says
Yeah-yeah, we heard that so many times, 'the LW says'. Where, my friend? Nah, ONLY Crumpp says.
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Originally posted by Crumpp
That's about a stupid statement Isegrim. Go look at the performance charts posted above. It clearly states DB605 with GM-1.
:aok
From K-4 (DB 605D) manual :
(http://www.x-plane.org/users/isegrim/109/K-4%20WEP%20time.jpg)
No mention of GM-1...
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314, or 25% of them alone were K-4s. Neither very-very late, they saw service first in October 1944, 200 already, few months after P-51D.
The 51-D was with the 4th FG 8th AF in Feb '44. That is 8 months before the G-10 and K-4 appeared. At that time (Oct '44) there was 12 FGs equiped with the 51-D. (~720 a/c) The USAAF had a total of 3341 51-Ds in Oct '44.
In Jan '45 there was 14 8th FGs with the 51-D(~840 a/c) At that time the LW could only muster 1462 servicable se fighters. The USAAF had 5002 fighter a/c at that time vs Germany.
That`s a LOT, not rare...
If that is so, why did so many Allied pilots complete their ToD without seeing any LW a/c?
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My God,
there are some desperate folks in this forum.
The loss rate of the 109 in landing accidents is documented. If you happen to own "JG53 Pik As" Series by Jochen Prien or "JG26 War Diaries" you can follow the 109's accidnet rate as the pilot training deteriorates in the Luftwaffe. Their is no way to confirm the 11,000 quoted by Flight Journal nor is their anyway to confirm the 5,000 other sources quote. The Fact remains the 109 is known for it's high landing accident rate by those who flew it.
Willy Messerschmitt designed the 109 landing gear with the intention of remove the drag cause by thick wing chords needed for wide track landing gear. The retracting mechanism for the 109's main landing gear was located in the fuselage giving the 109 a narrower wing profile at the fuselage. Tradeoff for this is a narrowtrack landing gear which decrease's the planes stability on landing making things more difficult for the pilot. The landing gear was splayed in an attempt to add stability. Angling the Gear means to maintain landing gear strength you have to have thicker material which is more wieght.
The 109 was known for weak landing gear, weak brakes, and an affinity for groundlooping. All these characteristics add up to increased landing and takeoff accidents. I would have thought so many "109" experts would have known this. I see what we have in reality is a bunch of "my plane is perfect and how dare you say it isn't".
http://www.xs4all.nl/~tozu/me109/foreign/109-Yugoslavia.htm
Here is an example.
Crumpp
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Further, as of 12.44
JGs and their theoretical establishment strength
JG1 - I, II, III, IV > 196 a/c
JG2 - I, II, III, IV > 196 a/c
JG3 - I, II, III, IV > 196 a/c
JG4 - I, II, III, IV > 196 a/c
JG5 - I, II, III, IV > 196 a/c
JG6 - I, II, III > 144 a/c
JG11 - I, II, III, IV > 196 a/c
JG26 - I, II, III > 144 a/c
JG27 - I, II, III, IV > 196 a/c
JG51 - I, II, III, IV > 196 a/c
JG52 - I, II, III, IV > 196 a/c
JG53 - I, II, III, IV > 196 a/c
JG54 - I, II, III, IV > 196 a/c
JG76 - I, II > 96 a/c
JG77 - I, II, III > 144 a/c
JG300 - I, II, III, IV > 196 a/c
JG301 - I, II, III, IV > 196 a/c
JG302 - I, II, III, IV > 196 a/c
Total: 3272 a/c
calculated as:
Stab = 4 a/c
Staffel = 12 a/c
Gruppe = 3 Staffel
Now I know that someone will come along and say the LW had x number of se fighters in the JGs. The question I ask them is, why then were the JGs only at 44.7% of their establishment strength if there was this x number of se a/c?
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This is getting truly ridiculous.
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Crumpp you haven't got a clue, Non combat 109 losses were no higher then any other lw fighter... Around 5% or so...
You get more ridiculous with each post..
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My God, there are some desperate folks in this forum.
More like disbelief than desperation - as you continue your "obsolete cursade", despite countless opinions that beg to differ, without any substantial evidence to back it up.
...
The loss rate of the 109 in landing accidents is documented. If you happen to own "JG53 Pik As" Series by Jochen Prien or "JG26 War Diaries" you can follow the 109's accident rate as the pilot training deteriorates in the Luftwaffe.
And is that a result of trainees lacking practical training being prematurely sent into a field of battle to return home after a stressful fight, or is it a result of a design flaw?
Landing accidents and inherent dangers of such action is common in virtually all aircraft and yet, such unfriendly characteristics alone is never a basis for claiming something to be obsolete - as practically no plane is ever "user-friendly" enough. From what you are implying it seems your standards of "user-friendliness" would be more suited modern-day planes with tricycle landing gears and electronic aviation, rather than a WW2 era tail-dragger.
Again, according to your standards, the inherent problems infesting some late-war US airframes also never really went away. The "Ensign Eliminator", as the F4U called was the most notorious Navy aircraft of them all. Not to mention the tendency to violently enter a spin during stall situations, which made this plane also very "user-unfriendly".
So, if we situate a simular comparison between a Fw190D and a F4U-4, with simular characteristics in performance specs and yet, hugely sensitive and unfriendly stall characteristics, inferior high speed handling, and potential dangers of landing accidents - is that alone enough for some of us to say "The F4U-4 was an obsolete design by 1945"?
...
Their is no way to confirm the 11,000 quoted by Flight Journal nor is their anyway to confirm the 5,000 other sources quote. The Fact remains the 109 is known for it's high landing accident rate by those who flew it.
Why should it be so? Okay let's actually try counting the actual reasons: It's a light-weight, relatively fragile airframe compared to bulky US planes. The problem of line of sight, is an inherent problem in all tail-draggers. The plane has a power-engine with a large amount of torque. Narrow landing carriages are always tricky.
Okay, which plane should we compare? How about the Spitfire? Simular performance specs, also a light built-plane with even narrower landing carriages than a Bf109?
...
Willy Messerschmitt designed the 109 landing gear with the intention of remove the drag cause by thick wing chords needed for wide track landing gear. The retracting mechanism for the 109's main landing gear was located in the fuselage giving the 109 a narrower wing profile at the fuselage. Tradeoff for this is a narrowtrack landing gear which decrease's the planes stability on landing making things more difficult for the pilot. The landing gear was splayed in an attempt to add stability. Angling the Gear means to maintain landing gear strength you have to have thicker material which is more weight.
Again, simular thing with basically anything with landing gears narrower than something like a P-47. The Spitfire steadily increased the width of the landing gears throughout development, but it never was wide as any other plane. So that should probably suggest the same sort of troubles as the 109 - except obviously no one seems to be wanting to drag this to the surface, or much better, no-one in their sane mind claims the Spitfire was "obsolete" due to its character quirks.
...
The 109 was known for weak landing gear, weak brakes, and an affinity for groundlooping. All these characteristics add up to increased landing and takeoff accidents.
How about this one? From a guy flew 109s decades after the Luftwaffe of the Third Reich went out of business?
"In summary, the Bf109G is a demanding aircraft to fly. The workload is high maintaining directional control on take-off and landing, although in flight the stalling and pitch characteristics are god. I would advise anyone planning to fly a '109 to get lots of experience and confidence in other large piston-engined taildraggers first.
However, if its peculiarities are understood and the take-off and landing limits are strictly adhered to the '109 can be operated perfectly safely. I treat the '109 with greater respect than anything else that I fly, but the challenge of trying to fly it well gives me greater satisfaction and enjoyment than probably any other aircraft. But I am never satisfied- I now have an ambition to fly an Emil; the Bf109E."
- Dave Southwood
Initially every aircraft has about equal amount of characteristics flaws. How about the Mustang's flawed design to shed its wings upon high speed maneuvering? The gun-jammin at high Gs? The Typhoon's notorious fame for losing its tail? The difficulties of the Corsair in vicious stalls and dangerous landings?
Name any WW2 plane you think is "not obsolete", and I'll bet we can find a design flaw, or a characteristic quirk that manifests as a potential problem. P-38? P-51? P-47? You name it, we'll deliver.
But unlike you, we have no intention of branding a certain plane "obsolete" due to its problems. Because clearly we know how to draw a line in "relative inferiority" and "absolute obseleteness".
So far what have you come up with?
1) Problems in control stiffness
2) Characteristic quirks during landings and take-offs
Come on, name any plane which you consider "not obsolete" by your own standards. Let's see if it doesn't have any "character flaw" of its own.
...
I would have thought so many "109" experts would have known this. I see what we have in reality is a bunch of "my plane is perfect and how dare you say it isn't".
You got it all wrong dude. It's "your plane sucks" vs "why is that?", which evidently the former doesn't seem to come with anything substantial.
Besides, this is an interesting question I'll bet - the landing/take-off difficulties was inherent in all 109s regardless of the timeline. How in the world is that going to help you prove that during a certain point the 109 started to become obsolete, when that 'problem' existed throughout the entire history of the airframe?
And that quirks, you seem to suggest, is such a problem that despite this plane(okay, granted the Bf109G-10 and K-4 shall not be used as a comparison. So, how about a G-6/AM or a G-6/AS? G-14?) gains superiority in number of performance attributes, it's still obsolete?
No, this is not about defending 'my plane'. It's about smacking a biased opinion that has no basis.
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Come to think of it, this is an interesting one.
Let's try a P-51D vs F4U-1 comparison. Despite all the performance advantages the F4U-1 holds, the P-51D is still more easier to fly - the F4U airframe with bad stall characteristics, huge torque, ground-looping tendencies.
So, according to your agenda, you reall do belive that the F4U-1 is an obsolete aircraft by 1944, don't you?
If you do not, then you have some serious double-standard problems.
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Crumpp really trusts his unit historian. I'm sure he's been told they found out the 109 was obsolete while on an OSS mission in Norway.
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Kweassa,
The P-51D had far worse stall characteristics.
The F4U stall was only bad for a carrier A/C. The P-40 and P-51 were both worse by comparison.
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Originally posted by MiloMorai
In Jan '45 there was 14 8th FGs with the 51-D(~840 a/c) At that time the LW could only muster 1462 servicable se fighters. The USAAF had 5002 fighter a/c at that time vs Germany.
It`s one of those really funny Mindless Moron comparisons, full USAAF strenght including servicable and non-sericable planes of both 1st line and both 2nd line units vs. only the servicable, only the 1st line units of the LW.
Comparing like with the like, on hand vs. on hand s-e engined fighters in 1st line (combat) units only, then we have 5002 USAAF fighter vs. 2493 LW s-e fighters: 1435 Bf 109s and 1058 other fighter types, mainly FW 190s. As per 'The last year of the LW' by Price, these units even then held an impressive 70-80% servicibility rate even in 1945 on avarage.
Further 527 and 359 were in 2nd line fighter units, not counting just planes standing in aircraft depots waiting to be issued.
Now I know that someone will come along and say the LW had x number of se fighters in the JGs. The question I ask them is, why then were the JGs only at 44.7% of their establishment strength if there was this x number of se a/c?
These are your numbers, not the actual facts. Furthermore, you don`t even underastand the definition of established strenght, on hand strenght, and combat-ready(=servicable) stregnht, for you are comparing servicable fighters with your claimed and obviously faulty est. strenght, and then claim they were at 44% strenght, whereas the figure that would give it is established strenght vs. on hand figures.
If that is so, why did so many Allied pilots complete their ToD without seeing any LW a/c?
If your claim is true, then many Allied pilots must have avoided the combat area far, far away.
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Kweassa,
The P-51D had far worse stall characteristics.
The F4U stall was only bad for a carrier A/C. The P-40 and P-51 were both worse by comparison.
That's even better! :D
Reverse the whole thing:
The P-51D is faster, good all around vision, incredibly long range and the "supreme" aircraft after 1944. But gee too bad - bad stall characteristics, potentially dangerous quirks and flaws compared to the rigid and rugged, straight-forward F4U-1..
Man, the P-51D is an obsolete craft compared to the F4U-1 !!
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You are always good for a chuckle Barbie.:)
If your claim is true, then many Allied pilots must have avoided the combat area far, far away.
[/b]
No Barbie, LW a/c were as scarce as teeth in a chicken's mouth.:rofl
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If you're saying that many US fighter pilots never saw a German plane over Europe then you're beyond all reason.
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What's the matter Barbie, can't admit you lied?
BarbNeither very-very late, they saw service first in October 1944, 200 already, few months after P-51D.
MMThe 51-D was with the 4th FG 8th AF in Feb '44. That is 8 months before the G-10 and K-4 appeared.
2493 is only 76% of the JGs full strength establishment of a/c. So why were they not at full establishment strength if Germany had so many se fighters? Could they not be brought up to full strength with those thousands off se fighters you claim were coming of the assembly lines?:eek: Also, 70% of the LW was facing the Western Allies so that has 1745 se fighters 'onhand' in the West.:)
75% servicability is only 1308 se fighters. Just remember that a 'u/s' a/c is just scrap metal.
Now take your own advice, and compare fighters in the West(ETO, MTO) only.:) Nice try at deseption, but not this time. But if you don't, the USAAF had 15,190 1st line fighters 'onhand' in Jan 1945.:) The RAF had well over 150 fighters squadrons to add in.:)
Well naturally I am using 'servicable' se fighters since the JGs, according to you, had thousands of se fighters that could replace those not servicable.:eek: Seems that was an impossibility . The USSAF had not problem replacing any a/c that went 'u/s' from the a/c parks holding thousands of ready replacment a/c.
......
Allied pilots saw many LW a/c, but not in the air. :) Just what was left of them > you know, thousands of wrecks.:rofl :aok
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You are beyond all reason.
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Its funny to read the BS topic.
Our Bf10G2/6 pilots did very well with obsolite POS planes during the ww2.
If you know squirks of yours AND opponet planes, then... Make it count. Rest is BS.
Get over it
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Hi Crumpp,
>As far as the late war 109's being obsolete. I have already covered that. With their control forces and manuverability problems at high speed the effectiveness of the plane for your average trained pilot placed in an ineffective status.
Nonsense. The high-speed manoeuvrability of the Me 109 did not get any worse during WW2, so if it was obsolete for that reason at the end of the war, it must have been obsolete for the same reason at the beginning of the war.
Not to mention that the P-47, the P-38 and the Spitfire all had high-speed controllability problems of their own, some of them worse than the Me 109's. Were they obsolete, too?
>Gunther Rall advises the pilot NOT to fly the plane unless he has a factory trained mechanic check out the brakes.
For flying an irreplaceable historic WW2 artifact worth millions of dollars, that sounds like a good idea. I'm sure the Luftwaffe pilots had their trained machanics check out the brakes during WW2, too.
>1/3 of the 109's manufactured were lost in landing and takeoff accidents!
If you're serious about that number, what's your source?
>The 109 did maintain some advantages throughout is lifecycle in WWII.
Against the P-51D, it held speed, climb, specific excess power and sustained turn advantages at most altitudes :-)
>However you had to be a really really good pilot to take advantage of them by 1944 and to most pilots the planes bad characteristics outweighed it's good ones.
Please be specific. Which bad characteristics? No sniper rifle comparisons please.
Regards,
Henning (HoHun)
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Hi Crumpp,
>The loss rate of the 109 in landing accidents is documented. If you happen to own "JG53 Pik As" Series by Jochen Prien or "JG26 War Diaries" you can follow the 109's accidnet rate as the pilot training deteriorates in the Luftwaffe. [...] The Fact remains the 109 is known for it's high landing accident rate by those who flew it.
Actually, I did an analysis of JG26 loss rates, and found that there was no change in the frequency of landing accidents when JG26 switched over to the Focke-Wulf Fw 190. Accordingly, using the very same source you suggested, we have to consider all claims about the excessive accident rate of the Me 109 a myth.
Regards,
Henning (HoHun)
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Hohun,
It does seem the Flight Journal figure I quoted comes from an "unknown" Flight Journal Source. However it still remains a fact due to the inherent design tradeoff's of the 109 that it did have a higher accident rate. I think it was called a "Pilot's Monument" in German when a pilot nosed over a 109.
As far as your "analysis" of the JG26 data, I will go so far as to call you a liar on that one.
Crumpp
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Calling someone a liar is easy but if you should also prove that somehow; otherwise people are thinking you're just a sore loser and not worth of converstion.
Put your money where your mouth is or quit calling people liars without any proofs.
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The geometry of the 109's l/g gave it a toe-in. So if a wing went even slightly high this toe-in would be exagerated and more so for the higher the wing went. If the pilot was not quick enough to catch this un-level wing set, the toe-in would cause the a/c to turn to the side with the wing high. The higher the wing, the quicker the turn.
.........
Staga, where were you when Barbi was doing his name calling?:eek: One would think you have a bias.;)
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Buy the book, spend the hundred bucks for the set and look it up yourself. Not going to spend the time and effort. Got a family to be with and I've already spent too much time digging through material and posting quotes and facts from it.
Straga
Has nothing to do with being a "sore loser" and everything to do with some folks absolutely denying the truth to the bitter end in spite of the facts. Makes me want to fly Allied planes!!
Let me summarize this discussion.
I quote Carson's conclusions about the stick forces of the 109 and the rudder forces being a problem. Everyone says "Ohh Carsons's an idiot and your one too for quoting him because he got the drag co-efficients wrong on the 109! Well, that maybe true but we weren't talking about the drag coefficients.
So I quote at least 3 other sources pointing to the 109's shortcomings and stick forces. 1 is Eric Browns Enemy Test Flight, 1 is General Adolf Galland, and the other is Hauptmann Gollob's official RLM test flight between a 109F4 and a 190A2.
Folks jump on the bandwagon and claim it's either a myth that has been blown out of proportion and Environmental factors will negate it. Why would this be blown out of proportion? Is it a plot to keep the 109 down? From taking it's rightful place in "Old Fighters" Home?? Maybe Hitech will see it and pork it for them??!!?? :rolleyes:
Galland opinion went much farther than Gollob's. Gollob only called the stick forces and maneuverability of a 109F4 at high speeds "unacceptable". Galland states the 109 was obsolete by 1943. You quote the leader of the Luftwaffe Single engine Dayfighters making a broad generalization about a plane. One that holds true give the realities the LW was under in the late war period and you find 3-4 zealots piling out of the woodwork making cases for variants that quite simply came too little too late to make an impact or are not even in the time period Galland is referring too. Then they want to point to the game and talk about how successful it is in AH. Again, it's not Europe in 1944!!
Then Folks want to know my definition of Obsolete. So I tell them. It may or may not be Gallands, the man is not alive to ask anymore. So then we get a dozen posts on how MY opinion is just plain wrong. Hey, I got the money and I bought the books and I read them. I don't make a living researching the 109. So when Willey Radinger says the 109 was long in the tooth in 1944 and had a rough time with the late war allied fighters, I believe him. Much more so than I do someone like GSchloltz, Isegrim, Hohun who is simply advancing an in game agenda.
NO WONDER the community came up with the name "LUFTWHINER". It fits!
:aok
Crumpp
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Hi Crumpp,
>However it still remains a fact due to the inherent design tradeoff's of the 109 that it did have a higher accident rate.
Fact by what source?
>I think it was called a "Pilot's Monument" in German when a pilot nosed over a 109.
"Fliegerdenkmal" applied to any nosed-over aircraft and was not specific to the Me 109.
>As far as your "analysis" of the JG26 data, I will go so far as to call you a liar on that one.
Well, then I'm sure then I have your absolute cooperation in verifying the data to prove that you're not a name-calling troll :-)
First, do you agree with the following total casualty numbers (casualty = "no" was not counted towards casualties)?
Note that only 3.2% of the casualties listed were attributed to "landing", with another 4.3% "crashed" without specification.
Cause Casualties
Spitfire 327
P-47 177
P-51 91
engine 79
crashed 54
B-17 44
landing 40
Hurricane 36
flak 31
combat 29
fighter 27
Tempest 27
collision 25
own flak 21
Mustang 18
Typhoon 17
takeoff 17
no fuel 15
P-38 14
missing 12
light flak 11
Spitfire XIV 10
ship flak 8
Blenheim 6
weather 6
grd collision 6
Morane 406 5
unknown 5
B-24 4
hit water 4
P-47 or P-38 4
Spitfire or P-47 4
vehicle 3
B-26 3
Spit XIV 3
Curtiss H75 3
hit ground 3
wing failed 3
captured 2
drowned 2
engine fire 2
bomb 2
hit sea 2
P-39 2
RAF ftr 2
rammed B-24 2
takeoff collision 2
strafed 2
crashed oof 1
Finn I-153 1
accident 1
engine/combat 1
air attack 1
Whirlwind 1
Defiant 1
defect 1
air collision 1
Bloch 152 1
B-17+P-47 1
bomber 1
Bf 109 1
Bf 110 1
cockpit fire 1
Bf 110? 1
Boston 1
bomber gunner 1
wing failed cbt 1
shot after f/l oof 1
none 1
own bomb 1
own naval flak 1
P-38 - coll 1
P-38 or P-47 1
hit hill 1
RR explosion 1
machine gun 1
Spitfire+ldg 1
Spitfire-coll 1
Spitfire? 1
Stirling/Spit 1
takeoff taxi 1
train strafed 1
RAF bomber 1
hit lines 1
flak+Tempest 1
flak+Typhoon 1
fuel leak 1
Fw 190 1
FW 190D 1
heavy flak 1
Morane+flak 1
hit church 1
Maquis 1
truck accident 1
hit tree after combat 1
a/f flak 1
Yak-3 1
lost control 1
flak+FAF Ftr 1
hit cable 1
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Hi Crumpp,
>Has nothing to do with being a "sore loser" and everything to do with some folks absolutely denying the truth to the bitter end in spite of the facts.
What facts? :-) You must be joking - all you quoted is opinions.
>"Ohh Carsons's an idiot and your one too for quoting him because he got the drag co-efficients wrong on the 109! Well, that maybe true but we weren't talking about the drag coefficients.
We were talking about technical obsolescence, and Carson based his verdict on a flawed analysis. If the analysis is flawed, so is the conclusion.
>One that holds true give the realities the LW was under in the late war period and you find 3-4 zealots piling out of the woodwork making cases for variants that quite simply came too little too late to make an impact or are not even in the time period Galland is referring too.
"Obsolete" is an absolute term if you're arguing that the Me 109 as a type was obsolete.
If only one Me 109 could be built at the end of the war that wasn't obsolete, the Me 109 can't have been obsolete as a type. The later the non-obsolete variant built, the more convincing the case. (More than 1000 Me 109G-10 and K-4 aircraft were built, by the way.)
>Then Folks want to know my definition of Obsolete. So I tell them.
Your definition?
"If the pilots are equal and the performance of their equipment is not, then the equipment is obsolete."
Your "facts"?
"It's a tough concept to wrap your mind around, especially when there are many different parameters in measuring plane performance that can be critical in a fight."
Of all those "many different parameters", you pick high speed handling and ease of handling on landing.
"Interesting" choice :-)
You seem to neglect that in the Me 109G-10 comparison against the P-51D, it was the Me 109 that held speed, climb, specific excess power and sustained turn advantages at most altitudes.
If you want to stay with your definition, you really should define "critical plane performance parameters in a fight" - that's what Kweassa asked you to do some dozens of posts back.
If you don't do that, you'll leave the impression that you're evading the topic.
Regards,
Henning (HoHun)
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and now... for something completly differnt.
who the hell cares about the 109, spits are way batter, and far batter looking
G,D&R :lol
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I quote Carson's conclusions about the stick forces of the 109 and the rudder forces being a problem. Everyone says "Ohh Carsons's an idiot and your one too for quoting him because he got the drag co-efficients wrong on the 109! Well, that maybe true but we weren't talking about the drag coefficients.
We were talking about Carson's credibility as a worthy source. Obviously, his knowledge was wrong, and you keep sticking to the argument that no matter what he got wrong, his overall conclusion is right. So who's being the more unreasonable person here?
So I quote at least 3 other sources pointing to the 109's shortcomings and stick forces. 1 is Eric Browns Enemy Test Flight, 1 is General Adolf Galland, and the other is Hauptmann Gollob's official RLM test flight between a 109F4 and a 190A2.
And in turn, the other people came up with other arguments that shortcomings and stickforce problems are not unique to the 109 - which I believe, should establish a reasonable doubt which is more than enough for anybody who could reason. The comparisons which you take so seriously, is not sufficient to brand a certain plane-type as "obsolete".
Come to think of it, you never did any comparisons at all so far.
1. You ignored the relative performance aspects which the 109 holds superior.
2. You ignored the relative deficiencies which the 109 didn't have but the "not-obsolete" planes did have.
3. All you took for as a fact is the few characteristic flaws of the 109 and refused to acknowledge such flaws were common in all planes.
4. And to top that all, in such a clearly biased attitude in actual comparison, you go so far as to call the other people "Luftwhiners" and claim it is a vain attempt for us to defend an "obsolete" plane, which you yourself never proved it being so.
So, again, who's being more unreasonable here?
Folks jump on the bandwagon and claim it's either a myth that has been blown out of proportion and Environmental factors will negate it. Why would this be blown out of proportion? Is it a plot to keep the 109 down? From taking it's rightful place in "Old Fighters" Home?? Maybe Hitech will see it and pork it for them??!!??
Your babbling now. People have come up with counter points to the problems you pick in which you have laid the basis to judge the 109 as obsolete by 1943, and you've so far not commented about them. Neither did you answer some valid questions.
Galland opinion went much farther than Gollob's. Gollob only called the stick forces and maneuverability of a 109F4 at high speeds "unacceptable". Galland states the 109 was obsolete by 1943. You quote the leader of the Luftwaffe Single engine Dayfighters making a broad generalization about a plane.
And people've already pointed out how you took out a line from a comment and warped and twisted the point. By your attitude, we could easily establish that Galland hated the Bf109E and wanted Spitfires instead, in 1940, when he had to address Goering. Which Galland himself, had to explain that people have warped his opinion to a point which he never intended. Basically, you're doing the same thing.
One that holds true give the realities the LW was under in the late war period and you find 3-4 zealots piling out of the woodwork making cases for variants that quite simply came too little too late to make an impact or are not even in the time period Galland is referring too.
The "variants", did not come too little too late. More than thousand of each types were produced by end of 1944, with still more than 5 months left for the war to end.
Also, even if we take the G-10 and the K-4 out of comparison, as you say it should be, the Gustavs between 1943 and 1944 still hold much same essential advantages against a contemporary US fighter. Which this fact, again, you fall deaf ears upon and do not address in your posts.
Then they want to point to the game and talk about how successful it is in AH. Again, it's not Europe in 1944!!
What happens in a game is not an exact reference of reality, but to a certain extent it does show how the actual fight might occur - since AH claims to use FM as realistic as the data they could gather.
An AH Bf109G-6 or a G-10, is competent enough to fight against a contemporary P-47 or a P-51. Give or take differences between reality and a game, still it reflects some important facts - such as the fact that the advantages in certain performance attributes often favors the 109 more than its competitor.
Ofcourse, like always, you refuse to acknowledge this fact and just cast it away with the argument "it don't count, because this is a game".
Then Folks want to know my definition of Obsolete. So I tell them. It may or may not be Gallands, the man is not alive to ask anymore. So then we get a dozen posts on how MY opinion is just plain wrong.
No, you got dozen posts in just exactly why you are wrong, which you've ignored time again. You're not listening.
Hey, I got the money and I bought the books and I read them. I don't make a living researching the 109.
So howcome you think you're opinion is absolutely more correct than some other people who obviously have a vast more knowledge about the 109?
So when Willey Radinger says the 109 was long in the tooth in 1944 and had a rough time with the late war allied fighters, I believe him. Much more so than I do someone like GSchloltz, Isegrim, Hohun who is simply advancing an in game agenda.
Oh I'd believe him too. But there's a big difference between "rough time" and "obsoleteness".
* You've never proved anything is obsolete.
* Your quoting things which others have never said.
* Your ignoring the points others have come up.
NO WONDER the community came up with the name "LUFTWHINER". It fits!
So howcome we're the guys suggesting you come up with actual performance comparison, and pick out just in which area the 109 is so inferior that the entire type is announced "obsolete" by 1943, and you're the guy who falls deaf ears on it?
Or how about my fun little comparison between the Corsair and the Mustang? No opinions about that either? Despite by your own definition it is more than enough to announce one of that type is "obsolete"?
Really, the "Luftwhiner" branding, in this thread at least, is nothing but a typical "Commie" outburst, friend. Too bad you haven't got Cohn and McCarthy beside you to just crush all opposition and bend reality to what you think as it should be.
You still have a lot of questions to answer. Call us Luftwhiners or whatever you want, but it still don't change the fact your arguing things without any basis.
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Actually the community didn't come up with the term I did :D
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Kweassa,
It's both Gollob's and Gallands words are directly quoted. My opinion never figured into it nor have I twisted anything.
The Stick Forces are modeled in AH. Just dive a 109, get it over 700 Km/H and try and recover it without trim forces. Carson's conclusions about the stick forces of a 109 were correct.
Moving on:
In analyzing the data from JG26.......
1. Someone must have alot of time on their hands to sit through 19 pages of causalty listing in alphbetical order for the 701 known causalties. To quote Don's site:
"The casualty data, on the other hand, can be considered to be accurate. The records of the Wehrmacht's World War II casualties are maintained with great care by the Deutsche Dienststelle, the German personnel bureau in Berlin. According to the official records, Jagdgeschwader 26 lost 701 pilots in combat (killed, missing, or taken prisoner.) The graph shows these combat losses in order to provide a direct comparision with the victory claims, but the Geschwader suffered many other losses which should be recognized. 121 pilots were killed in aircraft accidents—wing or engine failure, bad weather, lack of fuel, takeoff and landing mishaps, air collisions, and the catch-all "loss of control". Five pilots died in other types of accidents. And approximately sixty ground personnel died during the war, from a variety of causes.
Records of injuries are less comprehensive, but it is known that more than 300 JG 26 pilots were wounded in combat (some several times), and more than 100 were injured in flying accidents. Some of these men were put back on flying status within days, but many never returned to combat. Details may be viewed in the full casualty listings."
17 percent of the pilot killed were from flying accidents. Add in an equal number of injuries in accidents.....
Well 1/3 of your force out of the action from just landing and takeoff accidents might be a bit excessive even if almost 34 percent of your casualties are from accidents. HOWEVER it certainly had a higher than normal landing/takeoff accident rate.
Granted JG26 was an Me-109 ONLY JG for a short period of time and in it's Late War Period had only 1 Gruppe of 109's. JG 53 However remained a 109 JG throughout the war. On Page 968 of Volume III "JG 53 Pik As" by Jochen Prien the following is printed:
"The fuel shortage had a serious effect on the front-line units, it was downright devastating on the training units. The number of flying hours during training was constantly reduced on account of lack of fuel, especially training on the "fuel hungry" front line types such as the Bf-109 or FW-190. As a result, pilots were now being sent to the front line units with between three and five flying hours on the Bf-109. These youngsters were just able to take off and land their machines, but in combat against the superbly trained allied fighter pilots they had no chance. This situation was further aggrevated by the fact that both fighter types, the Bf-109 and the FW-190 were clearly inferior to their allied contemporaries at this time."
13 Sep 44.
During the Month of July 44 JG 53 suffered 14 casualties. 8 of them are listed as "Mechanical Malfunction/accident" which it is not listed what exactly happenend. The other seven are listed as "Air combat". JG 53 Pik As unfortunately doesn't have a compiled list of casualties and causes. At the conclusion of Each battle or campaign the losses are listed for that section.
2. Too bad no one has actually compiled the data. We can only speculate from Luftwaffe testimony.
3. It is a fact the 109 had a reputation in the Luftwaffe for being hard to take off and land, backed by it's landing gear engineering.
4. My speculation - 1/3 of your total losses from landing and take off alone is not correct but the number is certainly higher than a mere 5 percent and to claim the 109 was "no harder" than any other A/C to take off and land is just not correct.
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Maybe I'm just stupid.... but how does that make the 109 obsolete?
Even your latest quote (I think) had a couple contradictory statements in it, at least contradictory to what your point of view seems to be.
The number of flying hours during training was constantly reduced on account of lack of fuel, especially training on the "fuel hungry" front line types such as the Bf-109 or FW-190. As a result, pilots were now being sent to the front line units with between three and five flying hours on the Bf-109. These youngsters were just able to take off and land their machines, but in combat against the superbly trained allied fighter pilots they had no chance.
If the 109 was so especially difficult to take off and land... how were "youngsters" with 3 to 5 hours of experience in type able to do so?
Furthermore... I think the sentence afterward may have somewhat more to do with the LWs failure in the air, rather than the obsolescence of the 109 and 190. By late 1944 and 1945... Germany had no fuel to put fighters in the air. The 8th and 15th airforces oil offensive had actually paid dividends.
As far as performance characteristics go.
I'll use a G-6 vs a G-10 vs a P-51D.
G6 G10 P-51D
weight--- 6,940 lb-----------------7400 lb-------------------10,208 lb
wing A---174 sqft -----------------174 sqft------------------235.75 sqft
HP
SL---------1475 hp-----------------2000 hp------------------ 1490 hp
2km------??????---------------------????? -------------------1720 hp
6km ----- 1355 hp------------------????? --------------------1505 hp
WingL---39.88 lb/sqft-----------42.52 lb/sqft-------------43.03 lb/sqft
PwrL
SL--------4.70 lb/hp--------------3.70 lb/hp-----------------6.85 lb/hp
2km------??????--------------------?????---------------------5.93 lb/hp
6km------5.12 lb/hp----------------?????--------------------6.78 lb/hp
I think it is safe to assume that if the G-6 has lower powerloading than the P-51 at a given altitude, the G-10 will as well. After all, the engine in our G-10 is much more powerful than the G-6. All the HP ratings are for WEP (at least I think).
Finally, some in-game data from Aces High.
Comparing top speed- The G-10 is faster than the P-51D at all altitudes up to ~25k feet, where they are even. After 25k, the G-10 has an advantage, but it is markedly smaller than below 25k. The P-51D is much faster than the 109G-6 at all altitudes, from a ~27-28 mph advantage on the deck to a ~60 mph advantage at 30k.
Comparing climb rates - The G-6 climbs better than the P-51D at all altitudes up to 30k, with the exception of ~22.5k where they are briefly even. The advantage is ~600 fpm at SL, growing to ~900 fpm at 5k, then shrinking from there. The G-10 holds a ~1000fpm advantage at all altitudes up to 30k.
Comparing acceleration -
At sea level, from 150 mph to 250 mph, time in seconds.
G-10 17.1 seconds.
G-6 21.8 seconds
P-51 23.3 seconds
At 18k, same parameters
G-10 24.8 seconds
G-6 27.5 seconds
P-51D 29.9 seconds
As far as handling goes.. I can obviously only give in-game experience, but in my opinion a 109G-10 is very close to the P-51 in turn rate. The P-51 has a noticeably smaller radius. A dogfight between the two I'd say is about 60%-40% in favor of the 109. If the 109 comes in with more energy, I'd say it is about 80%-20% in favor of the 109. If the P-51 comes in with more energy, I'd say it is going to depend on how good the pilots are. If the P-51 is a good shot, he'll probably win. If not, the 109 will equalize energy states fairly quickly and then kill the P-51. The G-6 would not be noticeably different, with the exception that it would have a harder time equalizing energy states with the -51 if it started at an energy disadvantage.
As a "real-world" anecdote... many of the top LW "experten" felt that with a good pilot at the controls the 109 was more than a match for a 190. I'd tend to agree based on in-game experience.
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Hi Crumpp,
>Records of injuries are less comprehensive, but it is known that more than 300 JG 26 pilots were wounded in combat (some several times), and more than 100 were injured in flying accidents. Some of these men were put back on flying status within days, but many never returned to combat. Details may be viewed in the full casualty listings."
>17 percent of the pilot killed were from flying accidents. Add in an equal number of injuries in accidents.....
>Well 1/3 of your force out of the action from just landing and takeoff accidents might be a bit excessive even if almost 34 percent of your casualties are from accidents.
17% of 701 + 100 of 400 are not 34%, but just 20%. And it's not 20% "of your force", but 20% of the total cases of killed and wounded personnel.
>HOWEVER it certainly had a higher than normal landing/takeoff accident rate.
Well, since you've been unable to extract a landing/takeoff accident rate from the figures, can you at least give a figure for a normal landing/takeoff rate?
>4. My speculation - 1/3 of your total losses from landing and take off alone is not correct but the number is certainly higher than a mere 5 percent and to claim the 109 was "no harder" than any other A/C to take off and land is just not correct.
JG26 had 40 landing accidents and 17 take-off accidents in 1264 total losses. These are just 4.5%.
Your 1/3 is based on flawed math, and on adding all kinds of accidents that were listed with different causes than "take-off" or "landing".
Do a clean count, and you'll arrive at the same result as I do.
Regards,
Henning (HoHun)
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In the Finnish air force service the Bf 109 (about 160 planes) was damaged or destroyded in the take off or landing about 50-60 times (same plane might have had several accidents). But it should be noted that most of the accidents happened naturally in the training stage, most of the experienced pilots found the B 109 not difficult to take off and land if correct technique was used. Therefore it can be argued that the statistics of the JG 26 are not very valid data because the pilots were allready trained when they arrived to the unit.
gripen
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Therefore it can be argued that the statistics of the JG 26 are not very valid data because the pilots were allready trained when they arrived to the unit.
That brings out an interesting question: just what exactly is the problem with the 109 in landings and take-offs? Is it the plane? Or is it the pilot?
If pilots trained enough for fighter duties(which mind you, is as it should be!) don't have much problem in landings and take-offs, and the percentage of such accidents is not in anyway higher or lower than other cases - then the plane's got no problems.
Or, are we talking about trainees and their tendency to goof up things?
What gets even better is this: okay, let's take for granted that it is a pretty dangerous aircraft for fledgling pilots. But then, how does being a difficult aircraft to manage, mysteriously link itself to becoming an "obsolete" aircraft?
The Stick Forces are modeled in AH. Just dive a 109, get it over 700 Km/H and try and recover it without trim forces. Carson's conclusions about the stick forces of a 109 were correct.
Moving on:
There is debate whether a "heavy elevator response" means that it locked up or not. It's inconclusive at the moment.
Besides, even taking for granted that maneuvering at excessive speeds is difficult, you still have a lot to answer for - heavy stick forces needed to pull out of high speeds was not common to only the 109. It was basically all aircraft of that time.
The P-51 had a tendency of shedding its wings. The P-47 entered compressibility that lifted away only at lower altitudes. The P-38 had a design flaw which sent the plane soaring down to its death, which was only marginally solved by introducing a dive-flap system with its later versions.
You've got some explaining to do before just casually "moving on" - were all those planes "obsolete" too?
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Hohun,
17 percent are KILLED in accidents. More than 100 INJURED. Since the causalties are made up of both INJURED and KILLED I simply kept the INJURED percentage around the hundred mark.
You are right about the percentage being wrong. 100 Injured in accidents out of a total of 400 injuries is 25 percent of those injured occured in accidents.
Reread the post HoHun. I am not claiming that 1/3 of the total losses is caused by landing and take off accidents. Just that it is MUCH higher than 5 percent!!!
Urchin,
Pilot inexperience combined with the performance of the plane is the point. Sure a well trained pilot could handle the 109 no problem AND could use it's strengths in Energy combat (which is much superior but harder to master than angle fighting) to keep himself on equal footing. An inexperienced pilot could not. The LW was made up of about 2-3 percent very experienced pilots and 97-98 percent very poorly trained replacements. It's kind of like the RAF at the begining of the war. Out of neccessity they had to flood their ranks with poorly trained pilots. Difference is the A/C they flew, while not perfect, had some pilot friendly qualities and were better in Angle fighting which is much easier for the average person to grasp and the natural reaction in the air. So these newbies had a better chance of surviving and learning due to thier plane and its performance.
As to the 109's being obsolete, it's the Luftwaffe saying their planes were not up to par with the late war Allied fighters not Crumpp. I just quoted what's in the book. Looking at the Luftwaffe's situation in '44 I'd have to conclude that the 109 wasn't the best choice for them. They needed a replacement with better performance and more pilot friendly qualities. I will believe the published experts NOT a bunch of zealots on the BB.
Crumpp
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Urchin
At what weight did you calculate your numbers? When the 51D was in combat with LW a/c over Germany it had ~60% fuel. Same for the LW fighters, what was their fuel load? Using TO weights gives unrealistic resulting numbers.
hp chart
(http://www.fourthfightergroup.com/eagles/merlin66hpchart.jpg)
Kurt Tank should have been allowed to use the DB engines in his a/c. Then the LW would have had better a/c.;)
A little snippet about the A/AS engines.
"the increase in boost the supercharger proved not up to the task, being unable to maintain the boost at a high altitude."
hp(ps) chart for the DB605
(http://www.allaboutwarfare.com/files/uploads20/1084205497bh3pt.jpg)
It should also be noted that the valve seats had to be checked at 50 hrs.
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Yes, I realize that using take-off weight isn't completely accurate, but I think it is accurate enough to get a good idea of relative performance.
Lets say the P-51 has 60% fuel and has flown for a while. The 109s that had taken off to intercept would also not be at 100% fuel (hell, 60% might even be a good guess for them to, considering how short their legs were), so the ratio would be preserved. A 109-G6 at 60% fuel still has better powerloading than a P-51 at 60% fuel. It probably still has better wingloading, but I'm not certain about that.
Crumpp, I'd certainly agree that if the LW had been equipped with Spitfires or something similar then the poorly trained pilots would have been a little better off. Although your typical "engagement" in WW2 was little more than what I would call Bore N Zoom anyway, so I'm not sure how big a difference a better flat-turning aircraft would have made.
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Kweasa,
Generally the problem with the Bf 109 take off and landing was that it was less forgiving than other main fighters if the pilot did something wrong. I think someone posted Soutwood's lecture pdf sometime ago which contains a pretty good part on Bf 109 characters (still Southwood is relatively novice on Bf 109, some wartime pilots flew thousands of hours on it and never had an accident).
gripen
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gripen, but would a certain characteristic quirk of the plane, would go so far as to become a basis for claiming this particular plane type obsolete? Despite when relative performance comparison shows that it is in many areas, not just one, actually superior to its main contendor?
That's really the opinion I am looking for.
As to the 109's being obsolete, it's the Luftwaffe saying their planes were not up to par with the late war Allied fighters not Crumpp. I just quoted what's in the book. Looking at the Luftwaffe's situation in '44 I'd have to conclude that the 109 wasn't the best choice for them. They needed a replacement with better performance and more pilot friendly qualities. I will believe the published experts NOT a bunch of zealots on the BB.
Is that a step back? Because "that wasn't the best choice for them" definately does not imply the same thing you did when this discussion began, as in "obsolete by 1943. period".
Now what you're saying smells like "I don't know for sure, but thats what the experts say so I'll believe them".
But then again, how would you know who were right and wrong, when you still refuse any specific performance comparison?
Experts could be wrong about things, Crumpp. We may not have the best of data available, but we'd sure love to try and see just exactly what your 'experts' said, on which data and which analysis, comparing which stuff, so they came to the conclusion it was "obsolete".
Or better yet, maybe I could go ask someone like butch2k - who probably owns the most compiled data on 109s besides everyone else. If he says "it's not obsolete", then are you gonna change your opinion?
Man, that would be really something fun to try on our behalf.
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By no means is it a step back. The 109 was outclassed by late war allied fighters. The Luftwaffe knew it.
Crumpp
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Outclassed? more like outnumbered :D
Besides real men Fly Antons :D
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Has nothing to do with being a "sore loser" and everything to do with some folks absolutely denying the truth to the bitter end in spite of the facts.
You have NO facts, Crump. It`s just an endless flow of BS coing out of you.
I quote Carson's conclusions about the stick forces of the 109 and the rudder forces being a problem.
Carson quotes a RAE report of an early 109E variant, and wants to apply that to different models. Wrong. Crumpp tries the same. Wrong.
Everyone says "Ohh Carsons's an idiot and your one too for quoting him because he got the drag co-efficients wrong on the 109!
And they are right. :D
So I quote at least 3 other sources pointing to the 109's shortcomings and stick forces. 1 is Eric Browns Enemy Test Flight,
Uhm yes. You misquote them, that`s right. Eric Brown says the rudder forces, aileron forces were light. Crump simply reversed that.
Gollob only called the stick forces and maneuverability of a 109F4 at high speeds "unacceptable".
...yet even in British evaluation trials they state the Bf 109F was dived to no less than 420 mph IAS, where it could still do 'fairly tight turns'. More ? 109K manaul states that from a 850 km/h, 45 degree dive, the altitude required for recovery is no more than 400 meters. Hardly unaccaptable, even when we are talking the most critized control, the elevator.
Galland states the 109 was obsolete by 1943.
No, he does not.
So when Willey Radinger says the 109 was long in the tooth in 1944 and had a rough time with the late war allied fighters, I believe him.
As should everybody else, provided Radinger really said the things you put in his mouth. Well, he didn`t.
As for the Moron, per all sources I have seen, P-51D appeared in June 1944 in the 4th Fighter Group, not February, which would be rather surprising, as the P-51D production started only in february 1944, not to mention there was few Mustang FGs around, ie. 354th FG did combat mission in P-51Bs in December 1943 the earliest, the second being 357th FG in 11th Feb 1944, then the third 363rd in February 23rd etc - still just P-51Bs and Cs even in February 1944, no sign of Ds just being built in US factories.
unlikely that any planes saw service already in the same month.. For all practical puproses, the introduction of P-51D happened at the same month as the G-14/AS (June), a bit later than the similair G-6/AS (April or even sooner), and not much sooner than the G-10 and K-4s appearance to German units (October 1944, just 3-4 months later).
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Hi Crumpp,
>Reread the post HoHun. I am not claiming that 1/3 of the total losses is caused by landing and take off accidents. Just that it is MUCH higher than 5 percent!!!
Well, the only source you had for that claim was your prejudice while I actually evaluated the JG26 loss list. Since you're preferring prejudice over facts, I'll just consider you a troll and put you on my ignore list now.
For those who are genuinely interested, here's a list of all pilots who became casualties during take-off and landing incidents in JG26. These are 57 casualties out of 1264 total. The list is ordered alphabetically by last name.
Adam, Heinz-Günther, 12/20/42; Barthel, Alfred, 8/11/42; Bleich, Hans, 6/6/44; Bock, Otto, 3/25/45; Boeke, Günther, 2/7/45; Burckhardt, Gottfried, 12/18/44; Chemnitzer, Max, 10/7/44; Delor, Rudolf, 12/27/44; Dethloff, Hans-Heinz, 6/2/41; Dieterlen, Georg, 10/4/44; Dingler, Günther, 3/8/45; Dovnar, Alfred, 2/13/42; Effelsberg, Andreas, 2/23/45; Ellenrieder, Xaver, 4/16/45; Falkner, Gerhard, 4/19/43; Fast, Hans-Joachim, 3/7/43; Fröhlich, Hans-Jürgen, 11/17/41; Gehrke, Heinz, 9/11/44; Grams, Willi, 6/13/43; Hager, Robert, 1/20/43; Kemethmüller, Heinz, 11/4/44; Klingelhöfer, Paul, 2/12/45; Kolodzie, Herbert, 2/8/44; Kopp, Walter, 8/26/44; Langer, Alfred, 4/6/45; Langhammer, Gerhard, 5/12/44; Leder, Josef, 10/15/44; Leinberger, Rudolf, 4/5/45; Leitz, Emil, 7/28/43; Lentz, Ludwig, 5/3/43; Lindelaub, Friedrich, 11/11/43; Linecker, Alois, 10/21/41; Lyhs, Heinrich, 5/16/41; Mathony, Werner, 12/23/44; Melzer, Hermann, 5/10/41; Mietusch, Klaus, 4/12/44; Müller, Johann, 3/6/44; Nels, Franz, 12/10/40; Nieter, Heinz, 8/23/44; Oltmanns, Rudolf, 9/28/43; Paul, Arthur, 10/7/44; Przybyl, Leo, 2/10/45; Quitter, Fritz, 11/2/44; Richter, Adolf, 8/13/44; Schlenker, Erich, 6/9/44; Schlösser, Dietrich, 8/17/44; Schmelzer, Philipp, 1/15/44; Schmidtke, Günther, 8/17/43; Scholz, Erwin, 9/3/43; Scholz, Walter, 10/2/43; Schöndorf, Otto, 12/3/44; Schwan, Werner, 4/6/43; Steinberg, Günther, 10/4/43; Tebbe, Willi, 8/24/44; Thuy, Ernst, 3/25/45; Vogel, Richard, 3/24/44; Winter, Werner, 6/13/44
Regards,
Henning (HoHun)
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Well, my apoligies Barbi.:eek: :rolleyes: Being you usual, insulting self, still.:)
The D started to arrive in March 44.:) Since there was no real difference between the performance of the B/C/D/K, it is just another attempt on your part, to bs us.:) When the 51 showed up over Berlin in Feb 44, Herr Meyer knew the 'game' was over.
The G-14 production began in July 44, not June. The AS was only about 1 in 6 of G-14 production and was spread out along the whole production series. Even the larger Fo987 oil cooler was not installed in all a/c, reducing the power output potential of the engine.
As for your AS, a little snippet about the A/AS engines.
"the increase in boost the supercharger proved not up to the task, being unable to maintain the boost at a high altitude." Seems you are bsing some more with your performance claims.:)
It will be nice when Butch's 109 book will be published so that the true facts can be shown over your lies.
Now, where were all those thousands of a/c the Germans had, to bring the JGs up to full establishment strength?
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When i say that the supercharger was not up to the task it appears on boost higher than 1.8ata, as the critical alt is severely reduced when running on 1.98ata on the DB605DC.
If the plans to go for 2.3ata had been followed, there would have been a necessity to change the supercharger design.
G-14 production began in August 44 with 440 being produced, but some G-6/MW50 were produced before the official designation was changed to G-14.
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Kweasa,
I have not called the Bf 109 obsolote. In the terms of raw performance it was certainly pretty good at low and medium altitudes throughout war, at high altitude the allies had clear advantage from spring 1942 onwards (when the two stage Merlins and American turbo engines reached service). IMHO the main problem with the Bf 109 was that it was too small airframe to succesfully carry required weapon and fuel load in the last months of the war; same powerplant in a bit larger airframe would have been able to do required tasks (say bomber intercepting or tactical fighter) better while still maintaining good performance (as example of the P-51 and the Spitfire proves).
gripen
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If i seem to recall Galland suggestion to the 109 being put out of production was because it required much more pilot skill and training to perform well in the aircraft, against the 190 that had much more simpler controls ,better visibility ,wider tracklanding gear and was much more suited for the Bomber interception task than the 109 and of course was much more rugged.
Yet he flew on the 109 up until they sat his butt down as General of the day fighters and when he came back up he came back in 262s :D if I'm not mistaken.
:lol
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Well, here (in a flight sim board) most people are interested about fighter versus fighter fighting but in the last months of the war fighting against enemy fighters was pure waste of men, planes, fuel and ammo for Luftwaffe.
gripen
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Points of interest:
ad 1, High speed handling:
(http://www.x-plane.org/users/isegrim/FvsF/109f_afdu_HShand.jpg)
ad 2, As for the AS supercharger was not up to the task... really, the single stage AS and D engines outperformed the two-stage Merlins in power output at altitude, ie. the DB 605AS FTH height being 8000m, higher than any of the Merlin 6x series, and putting out apprx. 100 HP more, at much lower consumption etc.
As for the critical altitude of the engine being 'reduced', it`s rather irrevelant IMHO, the altitude power output remained the same, just at higher outputs yielded more power at low altitude; a limiting factor of course, the supercharger to extend the extra boost range. The performance would be the same, a K-4 would make just as well 680 km/h at 1.8ata at 10 000 m, and 680 km/h at 10 000 m with 1.98ata max boost, the only difference being an improvement of speed (~13-15km/h)between SL (594 km/h to 607 km/h) up to 7500m. Even at 2.3ata, the HA performance would be the very same - still680 km/h at 10 000m, even though the speed would further increase below 6000m, to about 640 km/h or so at SL... so I really don`t think it`s appropriate to speak about lack of s/c performance, since the s/c was well capable of creating VERY high performance at HAs. Lowered FTH is a natural thing to happen with increased boosts.
Same thing happened to Merlins, ie. Merlin 66 was unable to maintain max. boost after only 500 ft at 150 grade fuel and MS grade etc.
ad 3, Compared to the G-14 being produced only in August 1944, the Allies already captured imtact examples in mid July, ie see the 109lair for info, but Knoke`s diary already talks of Bf 109Gs 'with methanol injection and large compressors', ie. with high altitude 1800PS DB 605ASM as early as April 1944.
ad 4, "Even the larger Fo987 oil cooler was not installed in all a/c, reducing the power output potential of the engine"
Reducing? How? Power output was the same whatever oil cooler was installed.
ad 5, The AS was only about 1 in 6 of G-14 production and was spread out along the whole production series.
Rather interesting math, ie. considering at least 1835 G-14/AS were built, out of appx. 3000-4000 G-14s in total, which means every SECOND G-14 was a G-14/AS.
As a matter of fact, the output of the Regensburg factory was 1373 G-14/AS vs. 479 G-14s up to end of 1944 etc.
That similiar hysteria already caused Milo a permament banning on ubi forums, hopefully such action doesn`t wait for long here either. Ever since at ubi discussions are much more productive w/o provocations etc. that set the talk on sidetrack.
ad 5,
"In the terms of raw performance it was certainly pretty good at low and medium altitudes throughout war, at high altitude the allies had clear advantage from spring 1942 onwards (when the two stage Merlins and American turbo engines reached service). "
Hardly, it was rather more contested. In 1942, the Bf 109G had clearly better performance than the MkIX Spitfire at speed at all altitudes, including HA. It also outclimbed them, though at very HA the Spit had some climb advantage. At least on the paper, reality was something different,that there were rather few MkIXs around and many 109Gs.
It could match the speed of any turbocharged US desing of 1942 or 1943 - P-38s or P-47s, and outclimb them at all altitudes. P-47s increased their speed with the introduction of paddle blade props in 1943, but they were still not much faster, and were hopelessly outclimbed. P-38s never become any faster. Not counting GM-1 carrier Bf 109s of course, which would throughly swap the picture of HA performance again, but leave those special variants alone for the time being.
From 1943 onwards, most Spits produced were low altitude versions, with slightly worser performance at HA than previous MkIXFs, and close match in speed to 109Gs at HA - the picture did not change in their respect until early 1944, when the German began to use their /AS powered Bf 109s, which considerably outperformed any Spit IX`s speed at altitude. In fact, these high altitude 109s (G-6/AS, G-14/As, G-10, K-4) could cruise faster than the maximum 5min limit speed of Spitfires at those altitude at 8-9000m. :D The P-51 was, only comparable in speed, and again, inferior in climb. The general picture again, for 1944, is that the USAAF has types that are as fast as Bf 109s a HA as well, though outperformed by them in acceleration and climb rate, whereas 98% of the RAF`s planes simple can`t hope to catch Bf 109s anywhere above 16000 ft.
It appears the reality behind the claim 'clear Allied HA advantage from `42 onwards' is rather more complicated as some may imagine. So much that it can be as well the exact opposite case, ie. for 1944.
ad 6, As for the claims about small airframe being a limiting factor on the 109s - this was never proven in history. Fact is that they didn`t mount more fuel for the simple reason they didn`t need to, milage of the DB engines increased through the war, as newer models operated on higher CR, higher FTH with leaner mixtures but allowed for higher cruise speeds, as opposed to developments of R-R, which turned into fuel hogs, and required the increase of fuel capacity in late Spitfires by 50%, whereas range remained the same and endurance was even less than before; Bf 109F/G/K models continued to have more range on less fuel than Spitfires - something not only due to the increasing thirst of Merlins, but also because the fact that the larger airframe also creates more drag - no1 reason why Messerscmitt choosed a new way, high effiency via advanced solutions instead of relying on old school solutions.
Fuel tankage had to be increased due to the flaw of the Merlin powerplant, not by free choice. The added weight considerably detoriated handling characteristics and performance on the later Spits (and the same thing happened on P-51s with rear fusalge tank to maximise range - I always wondered how well would the P-51D do with a DB 605D instead of the Merlin 67 ), something that was certainly not desired by Messerscmitt, but thanks to the work of DB, he had other choices.
As the weapons being mounted, Bf 109s could mount up to 3 cannons, 20mm or even 30mm ones, and two heavy MGs - good enough as Allied bomber losses show. I certainly would not call an airframe unable to be armed effectively, which could carry no less than three MK 108s, and could also mount an MK 103, Hispanos etc with ease.
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Kweasa,
I have not called the Bf 109 obsolote. In the terms of raw performance it was certainly pretty good at low and medium altitudes throughout war, at high altitude the allies had clear advantage from spring 1942 onwards (when the two stage Merlins and American turbo engines reached service).
So you do agree that a certain characteristic flaw or a problem, is not enough to brand a certain plane "obsolete", right?
That's really all I wanted to know.
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Kweasa,
I definately agree in the terms of raw performance otherwise it depends on task.
Dear Isegrim,
I must wonder do you actually believe your own statements?
gripen
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Kweasa,
There is no doubt the 109 was not the right plane for the Luftwaffe in the last years of the war. It was a decade old design which had undergone an amazing transformation from it's original design. As Eric Brown says "longevity has never been a fighter's quality".
Galland call it Obsolete. My scanner is broken so you can buy the book "The Luftwaffe Force: A view from the Cockpit" and look it up yourself. It's a good book and worth the money. When or If you do I would appreciate hearing from you on this subject again.
Glasses,
You need to check your History. Galland took over as General of Dayfighters during the transition period for I/JG26 into 190's. He in fact did fly a 190 when he could "sneak" away for a combat sortie. There is even a pic in JG 26 War Diaries of him in the cockpit. It was Dora's who protected JV 44's Me 262's in the "Galland Circus". I am sure he could have had 109K4's do it if he wanted.
Isegrim,
Let not cherry pick. He did say the stick forces were light at the 109's "disappointingly slow" cruising speed. At high speed however things were very different. The 109's stick forces became "unacceptable" above 700 Km/H.
The control in question has been the rudder not the elevator.
Everyone I have quoted said exactly what I printed. That particular quote is on Page 7 of "Messerschmitt Bf 109F-K Development, Testing, and Production" by Willy Radinger and Wolfgang Otto. It's in the first paragraph second column near the top of the page and was written in Augsburg, October 98.
Crumpp
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There is no doubt the 109 was not the right plane for the Luftwaffe in the last years of the war. It was a decade old design which had undergone an amazing transformation from it's original design. As Eric Brown says "longevity has never been a fighter's quality".
Same thing with the Spitfire, which ancestry goes as far back to the Supermarine sea planes that won the Schneider Cup championships.
The Spitfire is actually very simular plane to the 109s. Light plane with high torque, narrow landing gears, poor frontal vision during take-offs and landings like any other tail dragger.
It was known for problematic performance at higher speeds, which was halfway solved in the roll axis by clipping the wings. It was a short-ranged point-defense inteceptor type of fighter, clearly almost identical in basic concept as the Bf109.
Throughout the war contemporary 109s and Spitfires have maintained a rivalry where each phase of development shifted the advantage from this plane to that continuously, which in overall made the two fighter types a very well matched set of planes.
Latewar Spitfires, like the early ones, verily "match" the late-war 109s.
Nobody to this day, calls the Spitfire an obsolete design, Crumpp.
Galland call it Obsolete. My scanner is broken so you can buy the book "The Luftwaffe Force: A view from the Cockpit" and look it up yourself. It's a good book and worth the money. When or If you do I would appreciate hearing from you on this subject again.
Galland also said "Give me Spitfires". He's a man known for tough comments and harsh words.
So what's the context of it? Care to describe it?
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I no longer wish to paticipate in the forum Barbi because the Mods do not have the cajones, one in particular who has a hate on for N. Americans and a luv for Eupies, to do to you what you say happened to me.:eek: Should we ask JW, Blutarski, Buzzsaw or Irrp about your conduct? Threads degenerated rather quickly after you posted, though those 4 mentioned did not degenerate to your low level.:) The only forum where one can get away calling someone a pedophile. :eek:
Well Barbi, if an engine has trouble cooling its oil, which the engine using the Fo870 did, it cannot maintain the power outputs you so dearly luv to state.
Not my math, but Prien and Rodeike who had ~1000 (G-14/AS) and ~5500(G-14) produced.
Just luv the way you pick and choose Barbi. The 6x series was not the HA series, the 7x series was.
Now what does the climb rate of American fighters matter. They were already at a high altitude.:confused: They had a good zoom climb and kept the hordes of LW fighters, you claim the LW had, from the bombers.
When are you going to stop stating those 'dream world' atas? Now what is so great about 11.76 lb boost? That is less than half of what the Merlin was capable of.
So extra fuel cause a degeneration of Allied a/c.:D When these Allied a/c met the LW in combat the fuel had been burned off. Another attempt by Barbi at data disinformation/manipulation. The drop tank and rack caused handling problems for the 109.:)
gripen, for sure he does.:) Seen through rose colored glass with horse blinders giving tunnel vision, the Germans were uber.
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Kweassa,
First of all you are right about the Schnieder Trophy planes being related to the Spitfire but only so far as the Bf-108 is related to the 109. The Spitfire entered RAF service shortly after the first prototype flew in 1938. The Bf-109 was already in service for 3 years with the LW and on the B varient.
The context of Gallands comment is in a Post-War debriefing to the USAAF on the Major Mistakes the Luftwaffe made in the conduct of the Air War. In the previous paragraph he discusses the RLM's Research, Develpment, and Production. The next paragraph is completely devoted to the mistake of keeping the 109 in service due to the fact the RLM had no replacement. That effort should have been put into developing a replacement instead of constantly updating an aging design.
Crumpp
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Hi Butch,
>When i say that the supercharger was not up to the task it appears on boost higher than 1.8ata, as the critical alt is severely reduced when running on 1.98ata on the DB605DC.
Actually, this doesn't have to do anything with the quality of the supercharger or the engine, but is just an inevitable byproduct of increasing boost.
It's interesting in this context that the German term for US: critical altitude, GB:full throttle height is Volldruckhöhe, "full pressure height". This alludes to the ability to maintain the full nominal pressure.
(The P-47D when run at full emergency power would display the same reduction of critical altitude as the Me 109 despite having a totally different supercharger system. I never heard anyone calling it "not up to it", though :-)
If you look at it from an engine output perspective, the higher boost yields the same power you'd get from the engine at the lower boost above full throttle height for low boost, and more at all altitudes below that.
So the supercharger on the DB605 was perfectly fine. It was not specialized for high altitude, as the two-stage Merlin of the P-51D, but the Me 109G-10 still outperformed the Mustang up high, so I'd not use the words "not up to the task" here :-)
Regards,
Henning (HoHun)
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HoHun i suggest you draw the curves for the DB/DC, you will see that the output drop is more pronounced than it should be which result in a no gain in output compared to 1.8ata from 1.5km to 3.0km.
The blower was definitely lacking some speed here else the increase in performance would have been much better. One would have expected a maximum output of 2075PS@2200m with a better blower while in real life 2050PS were achieved at 500m or so.
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Originally posted by butch2k
HoHun i suggest you draw the curves for the DB/DC, you will see that the output drop is more pronounced than it should be which result in a no gain in output compared to 1.8ata from 1.5km to 3.0km.
The blower was definitely lacking some speed here else the increase in performance would have been much better. One would have expected a maximum output of 2075PS@2200m with a better blower while in real life 2050PS were achieved at 500m or so.
I dont think it has to do with the 'quality' of the blower itself. Rather it seems DB and DC used different s/c speeds at the lower altitutudes, which is very evident if you look at not only the Sondernotleistung curves, but Kampfleistung as well at the same 1.45ata - for some reason, the DB puts out 60 PS more at SL up to an altitude where the two power outputs match at around 5000m IIRC. I wonder what the reason is...
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Originally posted by gripen
Dear Isegrim,
I must wonder do you actually believe your own statements?
gripen [/B]
Yep I do, and with a good reason :
Is it only me who sees the single-stage 109G-4 w. gunpods happens to be a good 15 km/h faster at altitude than those super-duper two stage Merlin Spits of 1942/43...
http://www.x-plane.org/users/isegrim/FvsF/fghterchart1.jpg
... or even better Allied Turbochargers of 1942..?
http://www.x-plane.org/users/isegrim/FvsF/P47fghterchart.jpg
And we did not throw in /AS types, G-10, K-4 which had far better altitude performance than those old mid-level DB 605As.
For your statement which I disagreed with was "at high altitude the allies had clear advantage from spring 1942 onwards (when the two stage Merlins and American turbo engines reached service). " Well, it appears to be wrong. But hey forget it, Grippy, no chance of that be ever possible in your mindset.
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Dear Isegrim,
That's exactly the problem; you believe anything which happens to support your agenda despte data might have obivious errors. Those Russian charts are a very good example; performance curves are wrong shaped for the DB605.
The reason for differences between (calculated) performance curves of the DB/DC is that DB used MW 50 which gives a small performance boost due to induction cooling.
gripen
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Originally posted by gripen
Dear Isegrim,
That's exactly the problem; you believe anything which happens to support your agenda despte data might have obivious errors. Those Russian charts are a very good example; performance curves are wrong shaped for the DB605.
'Obvious errors'? Like - as opposed to as Gripen thought, Bf 109G has as good and even better performance at high altitude vs. tubocharged/two staged Allied designs in `42? Yep, cant be anything but an error. :D
So typical Grippy, you come up with some sweeping generalisations w/o taking time to inspect the subject in depth, then you were corrected, and your reaction is to deny/ignore anything(=everything) that does not agree with you. You have the worst case of tunnel vision I have ever seen.
Maybe you should comment on the facts I pointed out in regards of the speeds of /AS and D equipped 109s of 1944, ie. they could cruise faster than the Spit IX could attain at full WEP at 8km.
Does not seem to support your (so far unsupported) claim of 'clear Allied superiority' at HAs.
The reason for differences between (calculated) performance curves of the DB/DC is that DB used MW 50 which gives a small performance boost due to induction cooling.
Nope. The effect of longer MW injection on the DB, and the resulting performance boost between 6-7.5km for the DB, alone does not gives answer to the difference in performance curves also displays at Kampfleistung, 1,45ata, and at low-medium altitudes.
At 1,45ata, MW 50 was not injected into the supercharger on DB 605D. Well, I would bet you know this but..
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Dear Isegrim,
Well, generally I believe just well documented real test data. Such data is easily available for the Spitfire IX and if one cares to dug a bit, such data is also available for the Bf 109G (including AS). So far I have not seen a test data which supports your agenda. Actually the tested AS plane failed to reach it's claimed critical altitude.
Regarding DB/DC, at least microfilms I have do not contain similar differences in 1,45 ata as in 1,98ata.
gripen
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Dear Isegrim,
Well, generally I believe just well documented real test data. Such data is easily available for the Spitfire IX and if one cares to dug a bit, such data is also available for the Bf 109G (including AS). So far I have not seen a test data which supports your agenda. Actually the tested AS plane failed to reach it's claimed critical altitude.
Very nice text. Only text though, a couple of generalisations, 'supported' by other generalisations.
We are left to believe the facts presented though, ie. maximum speed of, for example,
G-14/AS of 680 km/h at 7500m
is still higher speed developed at higher altitude, than the performance of
Spitfire IXLF (BS 310), ie. 650 km/h at 5950m.
It appears that there`s no sign of Allied superiority with two staged engines.
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Dear Isegrim,
Well, at least my copy of the G-14/AS datasheet says "Rechnung" as well as G-6/AS datasheet (tested AS failed to reach these "Rechnungs").
gripen
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My dear Gripen,
You have claimed many things in the past, never backed them up, just like in the current case. As in your original claim, your own imagination is mixed with some facts of reality, but your imagination provides the backbone.
Soviet testing? "All lies!"
Officially given Germans specs of G-10 and G-14/AS? "Lies as well!".
I am sure you will continue to make up things in the future as well. From your post history, the anti-109 bias is evident.
But until then, we are left with the facts:
G-14/AS : 680 km/h at 7500m
G-10 : 690 km/h at 7500m
K-4 : 715 km/h at 7500m
Spitfire IXLF (BS 310), ie. 650 km/h at 5950m, 642 km/h at 7500m..
The 'clearly superior', two-stage Merlin power MkIX LF is 40-60 km/h slower than single-stage high altitude Bf 109Gs.
PS : And I was being generous to Spit IXLF.
Tested Soviet IXLF failed to meet it`s techspecs, and the tested British IXLF could not go faster than 389 mph, or 626 km/h at 5900m...
I other words, test records show that the 'clearly superior' two staged Merlin 66 Spit XI LF was left behind even by the earlier Bf 109F-4. :D
And not even the infamous Gripnoodleh "I am all right, you are all totally wrong, in everything" mantra will help that.
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Dear Isegrim,
The funny thing is that you call calculations facts. There is real tested data on the AS model around, you just have to dug it out but the the data might be something you don't want to believe.
As usual, you try to put words to my mouth. It's not my problem if the data you use is calculations and/or contains clear errors. Generally a bit of source critics and logical thinking might make your living in these boards much easier.
gripen
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Dear Gripen,
Yes of course we all understand now, the 109s with /AS engines couldn`t even hope to cross 400mph. Clear as sunlight.
In fact, unlike all other planes, 109s worked the exact opposite way as a man of common sense would believe: the more powerful, higher rated altitude engines actually made them slower, and their altitude performance decreased. The use of an engine with 50% higer rated altitude, the use of broad blade propellors specially designed to perform the best in thin air all just decreased altitude performance, no doubt. In fact, there`s a secret, seen-by-no-one 1945 real life test on microfilm, recently found in Eskimo archieves, comparing the Emil and the K-4. The Emil outperforms the K at all altitudes, and is 234 km/h faster above 9000m. Also, there`s a huge 'Approved by Gripen Himself' stamp on it, so no doubt of it`s validity, as opposed to those idiots in Tsagi who dare to miscalculate things, and show the Bf 109G being doing well over 400mph even with a much weaker engine than the AS types.
Overwhelming evidence was shown that proves every single point of this story. It`s briefly summerized below:
...
...
Oh, silly of me, how could I forget all that ? Why is the scepticism? The Devil must be playing his tricks on my mind.
:rofl
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Dear Isegrim,
Well, let me put it this way: You can spend your time many ways; you can generate thousands of lines nonsense in various boards (as you currently do) or you can go out and actually dug out some real data.
Choice is your own.
gripen
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So nice of you to mention Barbi, using your Russian graph, that the Spit was up to 20kph faster than the G below ~6200m.:eek:
Is it only me who sees the single-stage 109G-4 w. gunpods happens to be a good 15 km/h faster at altitude than those super-duper two stage Merlin Spits of 1942/43
Correction Barbi, BS310 used a Merlin 70 which makes it a HF.:) Nice selective choice of data, for the max speed of 405mph(tas) was reached at 25400ft (652kph@7742m)
Spitfire IXLF (BS 310), ie. 650 km/h at 5950m, 642 km/h at 7500m.
(http://www.fourthfightergroup.com/eagles/bs310.gif)
Max cruise at altitude
G-6 - 596kph@6km (370mph@19685ft)
G-6/AS - 625kph @8.4km (388mph@26246ft) range 625km(388mi)
recorded by General Luftzeegmeister/C-E2 late '44
At 27000ft, the Spit BS310, did 650kph. Now there must be something wrong with Barbi's math, for 650 is a larger number than 625.
the speeds of /AS and D equipped 109s of 1944, ie. they could cruise faster than the Spit IX could attain at full WEP at 8km.
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Good God....
I fly exclusively Luftwaffe Iron. As a Generalization, Face it guys, with the exception of the Dora and the 109K LW Iron was behind the performance power curve. You simply have to be a better pilot to be successful in them.
Crumpp
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Hi Butch,
>The blower was definitely lacking some speed here else the increase in performance would have been much better. One would have expected a maximum output of 2075PS@2200m with a better blower while in real life 2050PS were achieved at 500m or so.
Well, there are multiple limitations to power at the high end that aren't necessarily caused by the supercharger.
The final power output probably was the result of carefully tailored compromises, and being below the optimum at low altitude wouldn't have been much of a problem as combat usually took place at medium to high altitude anyway.
Even with the limitation, the Me 109G-10 still is superior in speed and climb at low and medium altitudes to the P-51D, and still retains the climb advantage at high altitude. If compromises were necessary to achieve that kind of performance, I think Daimler-Benz picked them rather well.
In the end, it's performance that counts, and the late-war Me 109 was excellent in that regard.
Regards,
Henning (HoHun)
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Hi Gripen,
>Those Russian charts are a very good example; performance curves are wrong shaped for the DB605.
Hm, what do you mean? I believe they have made wrong assumptions about the convex/concave shape of the different sections of the graph, but overall, the shape of the Russian speed charts seem to show a fairly accurate portrayal of a single-stage, variable-speed supercharged DB605.
Regards,
Henning (HoHun)
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HoHun,
That's exactly the problem; the chart might not be based on real tests or the test data contains just couple test points. The Fw 190D curve has a very similar error. Overall I don't rate this kind of charts as reliable source, it would be much better if the real test data comes available from the Russian arhives for better judgement.
gripen
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So nice of you to mention Barbi, using your Russian graph, that the Spit was up to 20kph faster than the G below ~6200m.
Not bad for the 109G, since in these tests it carried gunpods which decreased speed by 8-15 km/h. But even this way, it`s superior to the two-staged Merlins at altitude, which is something being discussed.
Correction Barbi, BS310 used a Merlin 70 which makes it a HF.:) Nice selective choice of data, for the max speed of 405mph(tas) was reached at 25400ft (652kph@7742m)
You can only correct something that is incorrect, Moron.
ie.:
http://www.fourthfightergroup.com/eagles/ma648.html
4.2 Comparison of results with other Spitfire LF.Mk.IX aircraft. Figure 1 gives comparitive curves and the results are summarised in the table below:
Spitfire LF MkIX. BS.310
Engine : Merlin 66
http://www.fourthfightergroup.com/eagles/ma648speed.gif
At 27000ft, the Spit BS310, did 650kph. Now there must be something wrong with Barbi's math, for 650 is a larger number than 625.
Or maybe it`s Moron makes an idiot of himself again. :D
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Originally posted by HoHun
Hm, what do you mean? I believe they have made wrong assumptions about the convex/concave shape of the different sections of the graph, but overall, the shape of the Russian speed charts seem to show a fairly accurate portrayal of a single-stage, variable-speed supercharged DB605.
Just checked the Soviet speed curves vs. real-life German testing of WrkNr 14026, and there is perfect agreement between the shape of the German curves, and the altitude of 'break points'.
Dunno what Gryphon talks about again. Doubt that he does, either.
Both curves show the same, increasing performance gain with altitude up to 4700-4800m, which bulges out at 2500m. From 4800m onwards, the performance gain is linear up to 7000m, where the Volldruckhohe is reached.
It follows the power curve a un-rammed DB 605A, ie. which develops 1475 PS at 0m, that increases to 1550 PS at 2100, where the second s/c speed kicks in drains some performance gradually as the s/c spins up, until 5800m VDH, by which point it slowly decreased from 1550 PS to 1355 PS.
Under high speed level flight, this trends happens at a somewhat higher altitude.
(http://www.x-plane.org/users/isegrim/FvsF/P47fghterchart.jpg)
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Want to try again Barbi? Here is from the 4th site
(http://www.fourthfightergroup.com/eagles/bs310.gif)
LOL it says HF Mk IX BS310 (Merlin 70)
So not only your understanding of which number is greater than another but you have trouble reading.
This chart gives no indication to what model and engine fitted to the Spit.:rolleyes:
http://www.fourthfightergroup.com/eagles/ma648speed.gif
This is what your link goes to (http://www.fourthfightergroup.com/eagles/ma648.gif)
Please note the serial number, MA648.:eek:
Someone is appling the 'moron' name to the wrong person Barbi. Stop looking in the mirror..:rofl :aok
These are the Spits tested on the 4th site:
Spitfire F. Mk. IX BF.274 (Merlin 61)
Spitfire F. Mk. IX BS.428 (Merlin 61)
Spitfire F. Mk. IX BS.543 (Merlin)
Spitfire F. Mk. IX BS.55166 (Merlin 70)
Spitfire HF. Mk. IX EN.524 (Merlin 70)
Spitfire HF. Mk. IX BS.310 (Merlin 70)
Spitfire IX JL.165 (Merlin 66)
Spitfire LF Mk. IX MA.648 (Merlin 66)
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I kinda expected such hysterical reaction, and Moron getting himself even deeper in the mud.
Even if all he had to do is to go here,
http://www.fourthfightergroup.com/eagles/ma648.html
and scroll down to Paragraph 4.2.. :rofl
Gscholz summerized you the best, Moron.
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Milo: You're barking up the wrong tree. BS.310 was a trials machine that was equipped with various engines including the Merlin 66 and 70.
gripen: Performance results from flight trials of DB 605 A engined 109 Gs is rather interesting and informative ;)
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Milo,
Isegrim's data is consistant with Eric Brown's assesment of the 109G's series remaining a very competative dogfighter above 25,000 feet.
Crumpp
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Are you really that stupid Barbi? It would seem that you are. The Merlin 70 engine is a high altitude rated engine, so why would BS310 have a LF designation. BS310 is a HF that had a 66 installed, for a short time. Stop calling yourself a 'moron'.
Now what does this say? 3rd time posted, so read very carefully
(http://www.fourthfightergroup.com/eagles/bs310.gif)
mw, not according to the list of Spitfires that have test results on the 4th site. Note this is Barbi's reference source. It is also selectivity on his part to show the Spit in the worst posible way.
BS310 was manufactured(31.8.42)) as a HF, that had for a very short time, a 66 installed. Note the date of the BS310 and MA648 tests. Why did Barbi not give the data for MA648 which was the main subject of the report?
Some graphs to look at
(http://www.fourthfightergroup.com/eagles/spit9v109gspeed.jpg)
(http://www.fourthfightergroup.com/eagles/spit9v109gclimb.jpg)
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Milo: compare BS.310's curve and FTHs on the chart you just posted with the other Merlins; nuff said. I can prove you wrong, but that's not my intent. My advise, partly why I posted, is just drop that particular line of discussion, its a bad investment.
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Yeah, LOL, Mike was rather busy with those silly graphs during the last few days, it was fun to observe his progress. A genuie example of the 'credibility' of his site, he picked the worst performing 109s he could find, piled them together and compared them with hand-picked Spitfires.
As a matter fact, just look at a few examples what he compares :
109 G-1 Werknummer 14 026. Produced in February `42, ever since a testhack of Messerscmitt. The curves that he took are from a six week series of trials, that investigated the performance difference between DB 601E and 605A, primarly at ground level, and the radiator temperatures when built in the same airframe; altitude measurement we of secondary nature.
The plane went through 10 testflight, during which the engines were swapped 3 times, first the 601E was tested, then the 605A. One can imagine the aiframe`s condition by August 1942, when the 605A trials started... though I guess the most telling is the facts presented in the reports, ie. speeds achieved early in the trials with 601E and 605A in the end (both at Kampfleistung):
at 0m:
601 E : 514 km/h
605 A : 507 km/h
At critical altitude (VDH)
601 E : 622 km/h at 6000m
605 A : 627 km/h at 6100m
Now considering that the power outputs of 601E vs. 605A at 1.3ata:
601 E : 1200 PS at 0m, 1050 PS at 6000m. FTH : 4900m
605 A : 1310 PS at 0m, 1225 PS at 6000m. FTH : 5800m
Notice that the 601E powered 109G-1 gained 1100m due to the ram effect. By the time it was powered by the 605A, it only gained 300m .
Of course there are loads of other trials, each show the 109Gs rated altitudeplane`s as 7000m.
etc.
Also one wonders, how did Miky miss the Rechlin tests of G-1... you know, the ones that states 403 mph at 23 000 ft at 1.3ata ? But he makes qoutes from the very same Rechlin page a bit below. :D
Would you want to guess why it isn`t presented ? Or why the Finnish, NIIVVS trials with 109G-2 at 1.3ata are 'missed' somehow?
Now let`s see the Spitties he chose..oh, fine selection, indeed :
Mk IX, BS 543 : The prototype Mk IX LF tested well before the type went into service. Experimental engine, experimental propellor, none of which went into production in the same form.
409 mph is very nice, in fact, faster than the Mk VIIIs which were supposed to be faster than the Mk IXs. :D
But wait, there`s it little brother, BS 551, the HF prototype from the same experiments the previous comes from. Just about the same relevance to the actual performance of the serial plane, just compare EN 524, the serially produced HF Spit.
Mk IX, MA 648. Same trick by Mike, another prototype, this type with a experiment with the SU fuel pump. 411 mph, WOW, not bad for a prototype that never saw any service
No, I wonder, why this classy selection misses good old JL 165, a 'standard Spitfire Mk IX LF' to qoute it`s perfomance trials, that managed to do... uhm... 388 mph.
If someone wants, can make such interesting comparisons, Williams style, one can make it in a similair manner.
Say, take the G-2 tested by the NII VVS, and compare it to JL 165. :D
Yep, 413 mph done by the 109 at 23k ft, vs. a laughable 389 mph by the Mk IXLF. Hey Miky, isn`t that tough for an 1943 Spit not only to be outrun by a 109G by 25 mph at altitude, but it`s also
left behind by a two year older Bf 109F model?
You know, if I were Mike, and I would know what I knew what is coming, I would be really, REALLY quick in getting that page off the site, before perhaps it will be made an example about the mass number ofmanipulations going on that little spitty site.
A`la the Carson debunker articles. :D
I bet that would give some flavour to the site`s 'credibility', far and wide. :cool:
Seriously, the particular page can be hardly considered to be anything more than a byproduct of being a Spit zealot`s 109-envy, in which the extreme bias and the smell of primitive little tricks can be smelled a mile away. And if needed, I will prove that, line by line, and then make public for it, along with exposing every other silly little trick of that site, starting with the selective qouted Bf 109E evaluation, cutting half of the 109E vs. Spit I roll rate chart by Miky, or how he plays with holding back information about how exactly 'common' were the performance specs he posted for +25 lbs XIVs. All data needed for that is available to me and more. It`s rather boring to see those BS comparisons on Mike`s site, with the intent of misleading the public and serve the agenda.
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I am sure that Milo comes up with an answer, and this thread shall go on......and on....and on.....
But seriously, would I be wrong in concluding that the Spitfire is a slightly slower plane pr. Hp while being a better climber (Newtons) pr hp?
I'd rather agree on that, but that's just me :D
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Hi Gripen,
>That's exactly the problem; the chart might not be based on real tests or the test data contains just couple test points.
Well, that's standard operation procedure in flight tests. You'd probably do speed runs for example in 1 km intervals, plus one or two runs at the full throttle heights, and that's not quite enough to get details like the curvature perfectly right.
The Russians definitely tested several Gustav aircraft. According to Carl-Frederik Geust's "Under the Red Star" the NII VVS got 650 km/h @ 7000 m from a Me 109G-2/R6, and 16 - 19 km/h more from a clean Me 109G-2 (W.-Nr. 14513).
So the Tsagi book graphs showing around 670 km/h @ 7000 m seems very credible to me. As you already pointed out, the shape is not perfect, but I'd consider that a rather minor difference.
Regards,
Henning (HoHun)
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Hi Isegrim,
>Just checked the Soviet speed curves vs. real-life German testing of WrkNr 14026, and there is perfect agreement between the shape of the German curves, and the altitude of 'break points'.
Well, not quite perfect.
The Soviet curve starts off convex at minimum supercharger speed, then goes on straight from maximum supercharger speed to full throttle height.
It should rather be a straight start followed by a concave drop off.
I consider the Soviet curve good enough, though :-)
Regards,
Henning (HoHun)
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Dear Isegrim,
The subject of talking was about allied superiority in the high altitude engines. The Spitfire IX had been in service about two years when the Bf 109 with the AS engine reached service. At that time (spring 1944) the Spitfire XIV was allready in service as well as the P-51B with V-1650-3.
And you should also study how the supercharger of the DB 605 really worked.
HoHun,
Well, the question is open until someone comes out with more detailed data on the tests in Russia. If the testing organisation was as professional as you seem to believe, they should have known how the supercharger of the DB 605 worked. The Russians studied DB engines very carefully and actually they tried to develop variable speed supercharger for the M-106 (or something, can't remember). I have one Russian report on the DB605, very accurate report indeed.
Otherwise it's very unlikely that a Bf 109G-2 could reach 670km/h at standard condition, certainly not at 1,3ata 2600rpm. Generally many German datasets are created without proper compressebility corrections (also the others had similar problems with corrections), the best known example of this problem are those high speed dive tests on a Bf 109F/G hybrid; mach number values and speed values in km/h do not match. In the Russian dataset sea level speed is in right ballpark assuming 1,42ata 2800rpm and wing cannons (if compared to FAF tests) but high altitude speeds seems to be off; typical for correction errors.
gripen
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I belive Gripen is very very accurate there, - from the introduction of the Spitfire Mk IX, the Spits enjoyed almost 2 years of "ceiling supremacy".
I have a nice story of this somewhere, will try to dig it up and type it in here.
Still, they are faster/better up there for a reason.
1) More Hp at that altitude
2) Lower wingloading and lower spanloading
I know of a case where a pilot pushed what he said was a Spitfire IX (it was from memory, could have been a Mk IIX) up to 49K. That was an armed operational aircraft. That should give some idea about the quality at that altitude
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Oh, noticed a typo...
MK IIX is of course a Mk VIII......
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Originally posted by gripen
Dear Isegrim,
The subject of talking was about allied superiority in the high altitude engines.
How did this superiority manifest? Certainly not in aircraft performance at altitude, we would have notice that.
The Spitfire IX had been in service about two years when the Bf 109 with the AS engine reached service.
The Spit IX entered service the same as the 109G. As was shown to you above, they had pretty much identical high altitude performance - in fact the 109G was somewhat faster, even without GM-1 equipment, which it also employed (and boosted speed at altitude by 120 km/h) You can debate this as long as you want.
Bottomline again, the Spit IX was not widespread until late 1943, but the 109G was a common fighter in the LW already in 1942.
I guess even you wouldn`t argue the Spitfire V was not really up with the Gustav, or even the Friedrich in terms of high altitude performance.
As for the engines themselves, the power curves clearly tell the Merlin 61 had somewhat better HA output than the DB 605A, but not by much. The much more common Merlin 66 was practically identical at HA to the DB 605A.
At that time (spring 1944) the Spitfire XIV was allready in service as well as the P-51B with V-1650-3.
And how many of them, Gripen? Spring `44, there were about 2-3 Squadrons just equipping with Mk XIVs, not yet even seen combat. Their number did not increase later on, the XIV remained a rare plane - with stellar high altitude performance. So as the RAF stood by late 1944 - 95% of their Spitfires were Mk IXs with clearly inferior altitude performance to the, again, very common /AS types.
And you should also study how the supercharger of the DB 605 really worked.
I guess I have very detailed reports on that, thank you.
You should perhaps start to think how ram effect works with the fixed ratio 1st speed of the DB s/c.
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Hi Gripen,
>If the testing organisation was as professional as you seem to believe, they should have known how the supercharger of the DB 605 worked.
Small inaccuracies like the concave/convex mixup can be found everywhere in the books. The entire RAE Spitfire data consists of simplified climb charts, for example.
I don't believe the Tsagi comparison charts were drawn by the same people who conducted and evaluated the original tests, anyway.
>the best known example of this problem are those high speed dive tests on a Bf 109F/G hybrid; mach number values and speed values in km/h do not match.
Do you have the data that doesn't seem to match? When I checked the figures from Radinger/Schick recently, I didn't find anything unusual about them.
Compressibility correction was standard operation procedure in flight tests. Germany was leading the world in high-speed research, I'd be very surprised if they didn't knew about that.
Regards,
Henning (HoHun)
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The FAF pilots quoted the russian spitfires 'clumsy and slow at altitudes under 5000m over which the plane excells.'
The comparison was made to the brewster that was equipped with a standard airliner engine wo supercharger. It was adviced to get the spit and hurri into a turnfight where they were quote: 'helpless and easily killed.' This statement looks rather interesting if you compare the game performance.
Another quote: 'One mg burst in the forward section of a hurricane usually puts the plane in flames which consequently burned the pilot as the fuel tank was located between his legs.'
I've read several books and late interviews of FAF pilots who flew the G-2 without GM-1 and none of them has commented that the plane was either heavy or outclassed against the several types the soviets launched against them (P51, spit, hurri, airacobra, I-16, mig XX, LaGG xx just to name a few.)
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Hi Gripen,
>Otherwise it's very unlikely that a Bf 109G-2 could reach 670km/h at standard condition, certainly not at 1,3ata 2600rpm.
On the other hand, you might be right on the Russian tests.
It seems the Kennblatt quoted 649 km/h @ 7 km.
Regards,
Henning (HoHun)
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Hi Angus,
>I belive Gripen is very very accurate there, - from the introduction of the Spitfire Mk IX, the Spits enjoyed almost 2 years of "ceiling supremacy".
The initial production Spitfire IX (Merlin 61, +15 lbs) was indeed specialized for surprisingly high altitudes.
Since early Gustav performance is not finally agreed on, my personal estimate is that this Spitfire mark outran the Me 109G-2 above 8 km. The Spitfire also held the climb advantage there.
(This degree of specialization in my opinion makes it rather difficult to consider the Spitfire IX as the antidote for the Focke-Wulf. It was actually the antidote for the Me 109G! :-)
The later Spitfire IX (Merlin 66, +18 lbs) gave up that high altitude specialization in favour of better medium-altitude performance. This Spitfire was a pretty exact match for the Bf 109G-2 (1.3 ata, 2600 rpm), and suprisingly its area of superiority was at sea level! :-)
Spitfire and Me 109 are really an example for convergent evolution in my opinion.
Regards,
Henning (HoHun)
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Hi Siaf,
>I've read several books and late interviews of FAF pilots who flew the G-2 without GM-1 and none of them has commented that the plane was either heavy or outclassed against the several types the soviets launched against them (P51, spit, hurri, airacobra, I-16, mig XX, LaGG xx just to name a few.)
According to Geust, the Soviets agreed:
"The new Yak-1, Yak-7b and Yak-9 in production since beginning of 1943 and all lend-lease fighters delivered to USSR were considered to be inferior to the Bf-109G-2."
When the La-5FN finally appeared, it was reckoned to be the first fighter in Soviet service to be superior to the Bf 109G-2. (The earlier La-5 had been considered inferior above 3 km, and superior only at sea level.)
(Of course, you always have to be careful about tactical conclusions like these as they usually have a subjective perspective.)
Regards,
Henning (HoHun)
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Dear Isegrim,
Well, so far you have shown nothing which can be verified from the accurate test data. The Spitfire IX with the Merlin 61 performed better than the Bf 109G-2 above 25k. This can be easily verified from for example FAF test data and A&AEE data. Note that high altitude Spitfires used also quite similar system as GM-1 (LOX or something).
HoHun,
Original report on those dive tests should somewhere in the net. (one of those Bf 109 sites, can't remember which). Pressure calculation for the IAS does not contain compressebility correction. Actually one writer might release a study on this in the future.
The Bf 109G-2 should be able to reach about 640-650km/h at bit over 6,5km (early spec sheets say 7km but later ones say 6,6km, which seem to be quite accurate if compared to the test data) with 1,42ata and 2800rpm in the clean condition but that power setting was not used in the beginning. For the 1,3ata and 2600rpm the FAF data set on Bf 109G-2 is very good, actually you can check and calculate all the corrections by your self.
gripen
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Seriously, the particular page can be hardly considered to be anything more than a byproduct of being a Spit zealot`s 109-envy, in which the extreme bias and the smell of primitive little tricks can be smelled a mile away.
Nice description of yourself Barbi with the reversal of the Spit and 109.:). You are the master of twisting facts, untruths and data manipulation/misrepresention.
Mk IX, MA 648. Same trick by Mike, another prototype, this type with a experiment with the SU fuel pump. 411 mph, WOW, not bad for a prototype that never saw any service
Another example by Barbi of fact manipulation for it was also stated:
"These results compare favorably with those of other Spitfire LF Mk. IX aircraft, which fact is attributed cheifly to the higher full throttle height obtained with the S.U. pump."
LOL, lets use that 4.2 you are so fond off. The 3 other Spits had higher top speeds. Conclusion, JL165 was an abnormality. JL165 was a re-engined Mk V manufactured 27.3.43 with tests done 8+ months later. One has to wonder at what the previous 8-10 months had done to the airframe?
No, I wonder, why this classy selection misses good old JL 165, a 'standard Spitfire Mk IX LF' to qoute it`s perfomance trials, that managed to do... uhm... 388 mph.
Since the Spits were in the 2cd TAF, its opponents would not be the higher altitude 109s. B-17s, B-24s, P-38s, P-47s and P-51s were their opponents.
So as the RAF stood by late 1944 - 95% of their Spitfires were Mk IXs with clearly inferior altitude performance to the, again, very common /AS types.
For Reich and NW Europe.(Source: Alfred Price's Luftwaffe Data Book)
How many of the 342 flyable 109 were /AS types?(as of 31.5.44)
How many of the 446 flyable 109 were /AS types? (as of 10.1.45)
Nice to see HoHun, a rational discussion without the bigoted zealotness the 'brown shirted' Barbi shows.:aok
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A question for you all, regardless of speeds.
Would you think that a Spitfire (From Mk I to IX) would be able to invert the plane in the final approach, lower the gear while inverted, then roll onwards untill level and very quickly settle to a three-point landing?
It is possible in AH. I am wondering about the roll rates, and the stalling characteristics...
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Gripen;
Guess Finnish Bf109G-2's were having some strange powerups 'cause they achieved 640kmh with boost limited to 1,3ATA.
Aircrafts were dressed for battle (full fuel + ammo + radios, whole show).
http://www.kolumbus.fi/staga/scans/MT215_speed.jpg
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Hi Gripen,
> Note that high altitude Spitfires used also quite similar system as GM-1 (LOX or something).
LOX was liquid oxygen. As it provided pure oxygen without additional mass to improve internal cooling (which nitrous oxide did), it was limited to even higher altitudes than nitrous oxide. From what I read, it was only used on a handful of aircraft, probably those meant to chase the Ju 86 reconnaissance aircraft. German GM-1 systems could be converted to liquid oxygen use easily, but as nitrous oxide was considered superior, that was only done when no NO2 was available.
>Original report on those dive tests should somewhere in the net. (one of those Bf 109 sites, can't remember which).
Hm, I'd have to see that report for myself.
>The Bf 109G-2 should be able to reach about 640-650km/h at bit over 6,5km (early spec sheets say 7km but later ones say 6,6km, which seem to be quite accurate if compared to the test data) with 1,42ata and 2800rpm in the clean condition but that power setting was not used in the beginning.
Well, the Russians got a 7 km full throttle height, too, just as listed by the Kennblatt, which is for the 1.3 ata/2600 rpm setting. Applying compressibility correction to the Russian data, I arrive at 655 km/h @ km, which I consider a reliable value. The Russian G-2 did only use 1.3 ata/2600 rpm, which can be verified by the climb graph.
(1.4 ata/2800 rpm should give the G-2 around 670 km/h top speed, and around 21.3 m/s climb rate at sea level.)
Regards,
Henning (HoHun)
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Originally posted by Siaf__csf
Another quote: 'One mg burst in the forward section of a hurricane usually puts the plane in flames which consequently burned the pilot as the fuel tank was located between his legs.'
How I wish tgis were true... The AH hurricane is incredibly tough...
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btw FiAF's MT-215 was old plane and certainly not a "tuned-up" aircraft; It was used by Luftwaffe earlier as GJ+QA
(http://www.kolumbus.fi/staga/planes/megerfin2.jpg)
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The Hurricane MkI had a header tank which would easily burn.
The Mk II had this fixed somehow, not sure exactly how.
The first Spitfire Mk IX to go on a sweep over enemy territory was flown by Harry Broadhurst, - sort of "lent" to him by Jeffrey Quill. It was untouchable at altitude, and at high alt could also outclimb anything the Germans had at the time. As soon as the British had some squadrons of the Mk IX's they were the bosses of high altitude, and such for quite a while. They would even be cruising in battle formations at 43000 feet with fully armed aircraft, note that this is in 1942!!!
There is another merit of the Spitty that to my knowledge has not really been measured. That is climbing while banking, - corkscrewing upwards.
Used as an evasive, there was no plane that could completely follow the Spitty in that maneuver. I remember Johnny Johnson's tale of it, getting cornered off by a gaggle of 109's at low altitude he managed to corkscrew to 19K! They were lagging behind but still close when his second stage turbine jumped in, and a nice good-bye it was........
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Oh, by the way, I noticed that Milo's graph doesn't have a single spitty with the 25 lbs boost.
Nor the Mk VIII :D
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Originally posted by gripen
Dear Isegrim,
Well, so far you have shown nothing which can be verified from the accurate test data.
You say that Gripen, its rather debatable that I had shown nothing (or more, unworthy to be debated) - but what have you have shown up to now? Nothing at all. So far, you claimed half a dozen things, not backed up any of them, but went on the claim more. Not even references, Grippy. You wont make your point any crebibly this way.
As for what is accurate and what is not, I`d like to know what exactly makes you qualified enough to decide that single handedly. Have you been, for example offered with a job by the greatest aircraft tests centres of the world, like the engineers had been who worked at RAE, Rechlin, NACA, and in TSAGI, and whom you critize ?
The Spitfire IX with the Merlin 61 performed better than the Bf 109G-2 above 25k. This can be easily verified from for example FAF test data and A&AEE data.
And is disproved by the data from Rechlin and by Tsagi. Shown already. There wasnt real difference between the G-2 and F. IX at 25k, even though the Spit climbed better at the very high alitutudes - nobody could ever see me denying that. But thats all.
'Clear advantage'? Hardly. Especially not when compared to the far more common LF IXs (4 times as many built than F. IXs), which was at speed disadvantage vs. 109G at high altitude.
In comparison with the turbocharged P-47 and P-38 the Gustav shines even more.
You mentioned A&AEE data. Interesting comparison Gripen, since probably you have read the report itself, you have some idea of the condition of the plane :
- the oil cooler flap was o/order, stuck at full open position
- coolant thermostat failed during the tests, radiators become fully open with maximum drag at 30-32k ft
- propellor blades were damaged and holed by splinters
- the plane carried a tropical filter (-10mph)
- not to mention it was already battle damaged when captured by the Brits, when it awaited for repairs and could not be evacuated as it was not airworthy at the time
Note that high altitude Spitfires used also quite similar system as GM-1 (LOX or something).
And to what extent? There were only a handful of Spit IX around in 42, Gripen, and even as much as you love to loose connection with reality, even you cant deny that:
-Gustavs were FAR more widespread in use than MkIXs during 42-43
-the use of LOX vs. the use of GM-1 was practically nonexistent in the practice - every G-1 was capable of carrying GM-1, thats 160 or so planes alone, not counting the other conversions, which also amount hundreds.
The Bf 109G-2 should be able to reach about 640-650km/h at bit over 6,5km (early spec sheets say 7km but later ones say 6,6km, which seem to be quite accurate if compared to the test data) with 1,42ata and 2800rpm in the clean condition but that power setting was not used in the beginning.
Compared to that claim, the Soviet -tested Bf 109 G-2 W.Nr. 14513 reached 665 kph at 7000m at 1,42ata, and 649 km/h with gunpods.
Rechlin reports 649 km/h at 7000m at 1,3ata.
Rechlin and Tsagi are in good agreement, in view of the expected performance increase due to higher boost; +15 km/h appears to be logical. Also supported by Datenblatter for the 109G series, which state 540 km/h at 0m at 1.42ata for the early Gustavs. In fact, IXLFs (541 km/h) and 109G-2/G-4s were remarkably well matached in this respect when running at increased boost, and again, the 109G held the speed advantage at altitude.
The G-2/trop tested by the British in bad condition attained a rated altitude of 23200 ft at 1,3ata, as per the report, that is 7071m for you.
6,6 km VDH was way too low for the G-2 and G-4, only true for the G-6, which lost quite a bit of ram effect due to the higher drag.
What exactly proves your statements?
Oh, BTW, Gripen, have you managed to find out why the Soviet curves shapes are correct (in fact they are the very best examples how the DB 605 worked)?
I already gave you a hint, Grippy, it has something to do with ram effect. Don`t disappoint me with this intellectual lazyness.. :D
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HoHun,
After a hint from somewhere else I found a report (http://109lair.hobbyvista.com/techref/structures/tails/109.05e43_report/05e43-p1.htm). I don't know if this is the same which I have heard; I could not find clear errors in the quick dirty check except that the temperature range seem to be a bit od for winter time at given altitude range (might mean that the pressure and altitude meters had a lag in the dive).
Regarding the Russian tests; until some one comes out with more detailed data on them, I have no reason to change my opinions about them. Above mentioned graphs are quite questionable, as for example the Bf 109G AS did reach in the test about 630km/h at 10km (1,3ata 2600rpm) and Russian graph for the Bf 109G-2 gives 640km/h at same altitude. As for comparison the FAF test (very well documented) gives 552km/h at 10km and this is also supported by charts from another tests above. As for further comparison the Spitfire IX with the Merlin 66 did around 600km/h at 10km (JL 165) or more.
Generally it depends what you want to believe; well documented and logical data set or undccumented and unlogical.
Staga,
Well, as you probably know very well, the MT-215 was factory repaired plane ie in the very good condition, like a new. And the exact speed at 6300m (FTH) is 636km/h which is actually pretty good value if compared to other tests mentioned above.
Dear Isegrim,
Until you come up with the real data instead of thousands of words, there is no reason to argue. If the reports supporting your agenda exists, why not just post them like Staga posted a part of the FAF report and mw has the reports in his site.
Please enlight us on this RAM issue.
gripen
edit: The actual MAP at 10km was about 1.0ata in the case of the tested Bf 109G AS.
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Above mentioned graphs are quite questionable, as for example the Bf 109G AS did reach in the test about 630km/h at 10km (1,3ata 2600rpm) and Russian graph for the Bf 109G-2 gives 640km/h at same altitude..
Interesting how well this matches up Rechlin`s test data of G-1 at 1.3ata, exactly 640 km/h at 10km altitude.
http://www.x-plane.org/users/isegrim/109/109G-1_Rechlin-page3.jpg
As for why find the performance of G-6/AS well above it`s rated altitude 'strange' compared to G-2 is a mystery to me. Perhaps you should study the Bf 109 evolution a bit better.. the G-5/AS was apprx. 200 kg heavier (higher AoA required for level flight=more drag), the engine cowling was bigger, not to mention the tailwheel was non-retractable. Since top speed is about drag in the first place, and power requirements increase on the cube, it`s understandable why the G-6/AS
It also puts your comments on 'clear Allied superiority at HA' in a funny context, ie. Bf 109G was already as a good performer at vHA as the /AS types which left two staged Spitties well behind at altitude.
BTW, it`s also interesting to note that the (useless, as per Gripen) calculations of Messerscmitt for G-5/AS claimed 635 kph at 10km vs. 630 kph achieved during tests. Pardon me, Gripen, what was the line about 'underperforming' AS engines? ;)
As for the RAM, you get another day, hatto go.
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Dear Isegrim,
It would help a lot if you actually study the data you have; I have the same data set in the Microfilm and with a comment (actually the comment is underlined):
errechnete Leistungen!
Real data please. BTW this might explain the Russian data set; they might have used captured documents.
Regarding AS; The spec sheet gives FTH 8,8km for the 1,3ata 2600rpm while the real plane had FTH 8,3km.
gripen
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Hi Gripen,
>I don't know if this is the same which I have heard; I could not find clear errors in the quick dirty check except that the temperature range seem to be a bit od for winter time at given altitude range
I'm sure this is the same report Radinger used because the details are identical (converted Friedrich airplane, ejection seat, reduced aileron throw). I couldn't find anything wrong about the numbers quoted by Radinger, but I haven't seen the full report either.
>Generally it depends what you want to believe; well documented and logical data set or undccumented and unlogical.
Well, I'm afraid I couldn't find all of your "above" references. Still, if I'd have to decide on one realistic top speed for the Bf 109G-2 at 1.3 ata/2600 rpm, I'd not accept anything less than 650 km/h @ 7 km.
Regards,
Henning (HoHun)
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Does that mean that the AH G2 is limited to 10 min WEP at 1.3 ata? 650 km/h being 403 mph.
(http://www.hitechcreations.com/ahhelp/models/charts/109g2speed.gif)
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HoHun,
Regarding references, Staga posted FAF test link and the chart mw posted contains three very similar graphs. AFAIK local Virtualpilots here in Finland have scanned quite lot of FAF reports and if you ask kind they might send you the whole FAF report on the Bf 109. The Bf 109G AS report is available from the NASM in the Microfilm (reel number 2767, Starting from frame 711) it contains also a reference curve for the standard Bf 109G.
gripen
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tsk tsk, Isengrim, at it again.
quote:
"'Clear advantage'? Hardly. Especially not when compared to the far more common LF IXs (4 times as many built than F. IXs), which was at speed disadvantage vs. 109G at high altitude. "
The Spitfire Mk IX HF came FIRST, in 1942 actually. The LF was modified to what it became because of the need of a fighter that performed better at lower altitude bands.
I have not seen any data yet that threatens the Spit IX HF performance at high alt, and bear in mind that on Miko's chart we don't yet have the "juiced up" spitty.
As far as I can see, the chart gives a pretty good picture of what could have been a typical setup of those planes. It lacks (perhaps) the extreme models, - of BOTH.
It seems to show nicely also what one gets from historical accounts, - and mind you, you can spend thousands of lines here, but you cannot haggle down history.....
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Hi Angus:
"The Spitfire Mk IX HF came FIRST, in 1942 actually."
Read this (http://www.fourthfightergroup.com/eagles/spit9v109g.html) Work in progress. Hopefully that will sort the Spit IXs out some.
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mw, why is the 109G limited to only 385 mph (619 km/h) in that chart? I find it highly questionable considering the other charts posted in this thread.
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Wow, that page reeks of bias. Wing breakage? I've never heard of 109's losing wings, and neither has Franz Stigler as he said in an interview. That page is pure fantasy!
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^ hehe, you wish ;) I have the doc :)
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Then perhaps you would be so kind as to share them.
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I thought he pulled his site down afetr the folks on agw/wbs ignored his "data"...
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Hi Gripen: I accept your position here. I find the Russian curves somewhat more realistic than the Kennblatt, but they leave a lot to be desired. The engine limits and aircraft condition are often unknown. I agree the Finn test looks pretty good on the face of it and figured that was likely the closest to the truth before I analyzed the German trials. There are a few bad data points on the Finn data but they can be worked around. My question though is did they correct as follows: "Das Ergebnis ist auf Normaltemperatur und richtige Einstellung des Ladedruckreglers umgerechnet."? Radiator config? (Take it offline?) That German trials data is in such good agreement though, with realistic curves and coming from 2 different testing groups... very plausible. Were the Finn correction methods similar to the German? I have good reason to believe the British and German used similar reduction methods.
p.s. Send me an email will ya? I've been wanting to get in touch with you on occasion.
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Hi Angus,
>The Spitfire Mk IX HF came FIRST, in 1942 actually.
My impression was that the first of all was the Merlin 61 Spitfire IX.
>It seems to show nicely also what one gets from historical accounts, - and mind you, you can spend thousands of lines here, but you cannot haggle down history.....
Well, but it may take quite a few lines here or elsewhere to determine which data is truly representative for which situation.
Regards,
Henning (HoHun)
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Hi Mw,
>That German trials data is in such good agreement though, with realistic curves and coming from 2 different testing groups... very plausible.
One thing about the German curves in your diagram that is not quite plausible are the climb rate graphs.
They are most probably for a lower power setting than 2600 rpm/1.3 ata, both in rpm and in boost.
Regards,
Henning (HoHun)
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I did see an account of 109's loosing wings, but that was the 109E, after levelling out from a very fast dive.
Now there was a reason why they removed the wing mounted cannons, I think it was actually a strength issue.
But later model 109's,- never heard they had a problem with that.
Oh, and HoHun, you're right. Spitfire IX with a Merlin 61, my mistake calling it a HF.
It is good at high altitude none the less.....
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Some charts to argue over :p
(http://people.freenet.de/hausberg/spitvsbf.jpg)
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Hohun: All 3 german climb charts show the ladedruck curves below FTH at 1.3 with the report text confirming Steiglesitung n=2600 U/min, Pl = 1,3 ata.
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In the Spring of 1943 the RAF was also deploying the MK VIII Spitty, which is superior to the Mk IX in performance as well as having more range. I think that around the same time they started boosting up the other ones, all the way up to high heaven. Those 2 would look cute on the chart from Mike.
Does anyone have a quick info on the boostings. Didn't they go all the way up to 25 on the Mk IX? When?
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Angus, Herr Brown Shirt will show up and say there was ~6500t of 150 fuel produced in '44. (from a thread at Ubi)
It was in this thread (an interesting read:)) http://ubbxforums.ubi.com/6/ubb.x?a=tpc&s=400102&f=63110913&m=953109383 that a document was posted
(http://hometown.aol.co.uk/JStirlingBomber/150y.jpg)
Note, that the April amount is 1,533,000 Imp gal.
In July 1944, Tempests of 150 Wing were using 150 fuel and obtaining speeds of 415mph at 500ft.
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Well, I guess so.
I did notice a tendency to try to compare the Spitties to newer version 109's, and try to glue the Spit IX LF high alt performance as a comparison to the 109's.
From this chart, it seems that the boosted up Spitties were almost a standard already in jan. 1944, - I just wonder when they first appeared. My guess is early 1943.
So it seems that from 1942 to 1944 in regard of high alt performance, and 1943 to 1944 in regard of low alt performance, the Spitties held their edge nicely.
Or, to put it differently, a 109 pilot mixing it with a Spitty would not know if he could run away from it, nor climb away from it, and certainly not turn with it, - getting into a tough spot the only alternative would be to dive, - which is pretty much what they did, - they would always be able to make some space that way......
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Must be nice rewriting history.
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Originally posted by GScholz
mw, why is the 109G limited to only 385 mph (619 km/h) in that chart? I find it highly questionable considering the other charts posted in this thread.
Its quite simply why, because MW is just so cheap. He selected the best performing Spits, and compared them to the lowest performing 109Gs. The usual primitive BS from Mike, just look at his site, its a *****ing joke how he picks the data and presents it.
Among them the mentioned 109G-1 trial, which was about swapping the 601E and 605A engines in the same airframe. The results are selected because they are the lowest that can be found for any 109G.
Quite clear from the rated altitudes of the same plane and the speed attained vs. engine power outputs :
At critical altitude (VDH)
601 E : 622 km/h at 6000m
605 A : 627 km/h at 6100m
Now considering that the power outputs of 601E vs. 605A at 1.3ata:
601 E : 1200 PS at 0m, 1050 PS at 6000m. FTH : 4900m
605 A : 1310 PS at 0m, 1225 PS at 6000m. FTH : 5800m
Notice that the 601E powered 109G-1 gained 1100m due to the ram effect. By the time it was powered by the 605A, it only gained 300m .
Oh yeah, as per Miky, the difference 175 extra HP that the 605A has, with a propellor designed for higher altitudes, will give a whole 5 km/h (3mph) difference and an increase of 100m (300ft) altogether.
And who will buy this BS, Miky? A small circle of mindless Spit fanatics, that being you yourself and Nashwan-the-fantatic-Brit? :rofl
And as for in 1942-43? Who do you think you are fooling Mike, yourself maybe ? Want an 1942 comparison? Okey-dokey, compare the Mk IX F at +15 lbs, or even better, the pathetic MkV vs. the G-2s at 1.3ata, `cos the Brits mostly didn`t have anything better than those Mk V cannon fodders, as their combat record also show! :D
Want 1943 comparison? Fine, but why not include 1.42ata data results? Oh, NOW THAT would be unfair, isn`t it, LOL, only the prototype Spitties,...
As for the trials, I can send them to you Gscholz. Mike probably doesnt know, or maybe he knows (who cares) but he received those trials from me via Neil, along with information on 109 introduction dates. Unlike Neil Stirling, who does a fair job in comparing these fighters under equal conditions, Mike`s only agenda is to make the Spitty look like as it is in his nighltly wet dreams. :D
So just drop me a mail, Scholz, and the trials will follow. Information is the best way to fight this stupid BS. Carson already got what he deserves from Niklas, now it`s time to put Mr. Willy in his place as well.
Similiar joke comparisions can be made, let`s compare
Mk IXLF JL 165 at +18lbs
vs.
Tsagi`s 109 G-2, shall we:
SL speed :
109G-2 : 530 km/h
Mk IX LF : 515 km/h
at altitude :
109 G-2 : 665 km/h at 7000 m.
Mk IX LF : 624 km/h 5900 m.
Gee, aint that Spitfire Mk IX LF a good deal slower ? Let`s look at the really high altitude:
at 9100m :
109G-2 : 650 km/h
Mk IX LF : 611 km/h
Spit gets the low end of stick, as usual. :D
Here are the speed curves themselves :
http://www.fourthfightergroup.com/eagles/jl165speed.gif
http://www.x-plane.org/users/isegrim/109/fghterchart.jpg
Both are real life test, Miky. How `bout comparing these, these are real life test.
Well don`t hold your breath. :D
Now the difference between me, and Miky is that I won`t select JL 165 as a basis of comparison, because it`s not the best they have out there. I will compare like with the like, not worst from the other side, best of my side.
But of course, good planes don`t need cheat to shine. Only the suckers require that. :rofl
Mike`s comparsion is a joke, just like Mike himself. An revision of it is already under way, it will be posted everywhere. Eventually his own crap will turn against him and will make him even less credible if that`s still possible.
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Well, Isengrim, you will however pick a Spit IX LF for high altitude comparison, while that plane is optimized for low alt. Where is the difference in that?
The graph could surely do well with a couple of better performing 109's, and I miss the 109G6, however, the Overboosted Spits and the Mk VIII for instance aren't there either.....
Btw, would some of you happen to have the charts broken down in numbers? Would be nice to break this down a bit more in excel and make a new chart that suits "better" :D
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Angus, IX HF Spits were rare (400 produced or so), I give you anytime they were faster than the usual 109Gs at altitude. 109G w. GM-1 - now that`s another question. ;)
As for XLS, I have all the document Mike used for this 'comparision', and it`s already in Excell. It`s a matter of free time when the revision is ready. This will point out what half-truths and full lies Mike employed in his article (just one example - he states the radiators were 50mm all the time, and it`s the minimum drag position. In reality, half those tests were done with 100mm open radiators, and they could be fully closed (=0mm). Fast level flight was done at 40mm by standard, BTW.)
When my site is ready, a fair comparison will be posted on it, with appropriate boost in the time period, and good performing planes vs. good performing planes. Ie. for Mk IX LF performance, BS 310 w. Merlin 66 will be used. Standard plane, w. logical performance. Fair, don`t you think?
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My email addy is in my sig Isegrim, I'd be grateful if you mail me those tests. :) (I don't know the size limit on this email account, so if the files are big we'll have to work something out).
>>>
[rant]I really hate these "my Merlin is bigger than your DB" and vice versa. Exchange Spit and 109 with Bush and Kerry and you've got the same crap going in the O'Club. It is counterproductive and doesn't get us anywhere but stuck in stupid flamefests. Being an enthusiast is all good and well, but being obsessive to the point of dishonesty about the performance of 60 year old airplanes is probably grounds for a psycho evaluation.[/rant]
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A quick one here.
If the archives are big, try to chop them down with with WinRAR or WinZIP.
There is also a very good freeware program around called File splitter. I think I may actually have it in the setup form on my HD. It is small, so I could mail it.
Anyway, if you have a good bandwith, mail me too, - burns@isholf.is with something like AIRCRAFT in the subject line (Spam problems).
I am serious about making a graph, - need to excercize excel a bit anyway ;)
About the HF Spits....I seem to have mixed things a bit.
I thought that HF just stood for the high-alt optimized engines, but that is apparently not right.
However, Spits with engines optimized for that high alt work were very much more in number that you state, -the Merlin 61 equipped Spits arriving in 1942 would count as such, since they had quite a bit better performance than the 109's at high alt in the current timeframe.
I have the number somewhere near, I'll post it ASAP
Have a good day
Angus
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[rant]I really hate these "my Merlin is bigger than your DB" and vice versa. It is counterproductive and doesn't get us anywhere but stuck in stupid flamefests. Being an enthusiast is all good and well, but being obsessive to the point of dishonesty about the performance of 60 year old airplanes is probably grounds for a psycho evaluation.[/rant]
A perfect description of Herr Brown Shirt.:aok
If one wants an un-biased dialog about the 109s, Butch2k is the person to listen to for he has no agenda.:)
........
Now the difference between me, and Miky is that I won`t select JL 165 as a basis of comparison, because it`s not the best they have out there.
Glad to hear that, yet a link and data is provided to this a/c.:rolleyes: JL165 was manufactured as a Mk V and was 10 months old when tested.:eek: Now did not someone complain about an 'old' G type? Comparisons to the /AS types can not be done for 1943 since they did not appear til May 1944.
Want 1943 comparison? Fine, but why not include 1.42ata data results?
1.42ata was not cleared for use til the spring of 1944. And Herr Brown Shirt yaps about biased graphs.:rolleyes: :rofl
I always have a good chuckle when Barbi compares engine weights. What he so conviently leaves out is that to get the extra performance from the DB engines he forgets to add the weight associated with the 'boost juice'. GM1 added 434lb(195kg).
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Hi Angus,
>Oh, and HoHun, you're right. Spitfire IX with a Merlin 61, my mistake calling it a HF.
>It is good at high altitude none the less.....
Roger that! I'd say it represented the peak of the race for altitude :-) For some reasons, that race was abandoned shortly after the introduction of the (Merlin 61) Spitfire IX. The Luftwaffe had geared up for production of the Fw 190B, which would have been the high-altitude Focke-Wulf with suprisingly good performance up high, but canceled it right before it was to go on the production lines. Subsequent Spitfires got engines designed for lower altitudes, and the P-51 swapped its high-altitude Merlin for a medium-altitude one, too.
I'm not sure what the reasons were for this paradigm change - it might be that stratospheric flight without pressure cabins was fairly dangerous in itself, even before you ever met an enemy up there.
Regards,
Henning (HoHun)
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Hi Mw,
>Hohun: All 3 german climb charts show the ladedruck curves below FTH at 1.3 with the report text confirming Steiglesitung n=2600 U/min, Pl = 1,3 ata.
Well, I don't have the original charts so I can't comment on the reasons, but the climb graphs show both an inferior peak climb rate and an inferior critical altitude to what a DB605A providing 1300 HP at sea level at 2600 rpm/1.3 ata would yield.
For aerodynamical reasons, climb graphs can be assessed quite accurately, and I'd say 2 of the 3 graphs would match a 2300 rpm/1.15 ata climb nicely. The third is plain weird :-)
Regards,
Henning (HoHun)
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Hi again,
>Anyway, if you have a good bandwith, mail me too, - burns@isholf.is with something like AIRCRAFT in the subject line (Spam problems).
A copy to heruch@aol.com would be highly appreciated, too! :-)
Regards,
Henning (HoHun)
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For HoHun:
From Jeffrey Quill:
"Then, at some indefinite time in 1942, there seemed to be a change of tactical philosophy on both sides. It was as if, by some sort of some tacit mutual consent between enemies, it was realised that the band between 30.000 and 40.000 was a silly place in which to have an air battle, and the fighting subsequently tended to drop down into the more practical regions roughly between 15.000 and 25.000 feet."
:)
For Isengrim:
The Spitfire IX LF was made by demand for a higher performance at lower altitude. There were many enough for the high alt work. And there was ample boosterspice around as well ;)
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mw,
The FAF tests were done shortly following way: The meters (speed, altitude, MAP, etc.) of the plane were checked and calibrated. The error of the speed meter was measured by flying test track (four times, they liked to do it couple times more but the track was quite far away) and the correcting curve was created (for CAS) with known conditions (wind, pressure, temp etc.).The tests flight were flown in the Malmi and conditions were measured by sending a weather balloon same time as test flights happened. The Pilot recorded the results and for example in the speed test measurements with corrections were following at FTH.
Measured altitude: 6300m
CINA altitude: 6420m
Air density: 0,645 kg/m3
Indicated speed: 465km/h
Density and instrument error corrected airspeed: 652km/h
Compressibility corrected airspeed: 636km/h
Measured RPM: 2580rpm
Corrected RPM: 2540rpm
MAP: 1,30ata
Note that RPM was a bit lower than spec, that partially explains a bit lower high altitude performance if compared to some other tests. The Pilot made some notes on radiator flap position but not very exact(used automatic setting).One trick the pilot notes, is that he made climb test at a bit higher speed than supposed optimal to keep radiators shut.
The results are corrected to normal conditions (CINA) and as can be seen from the MAP curve, the supercharger was set right. I don't see any real errors in these tests nor bad points.
Isegrim,
The critical altitude of the DB 605 given in the specs (5800m at 1,3ata 2600rpm) is with some RAM (about climb speed). See for example spec chart posted above. Quick and dirty estimate for the unrammed FTH of the DB 605A is about 5200m at 1,3ata 2600rpm.
HoHun,
Regarding the change of the V-1650-3 to the V-1650-7 in the P-51, the reason is simply that 1943 the USAAF saw the P-51 as tactical fighter. Last year came out a quite interesting book on this issue: "P-51 Mustang; Developement of theLong-Range Escort Fighter" by Paul A. Ludwig.
gripen
edit: The FAF speed tests on Bf 109G-2 were flown the radiators at shut position.
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Hi gripen: Thanks for taking to time to provide the FAF test info. Very interesting! :)
Regarding the various Merlins in the Spit IX, I think it was Lovsey from Rolls Royce who put it "Horses for Courses". ;)
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Hi Gripen,
>Compressibility corrected airspeed: 636km/h
>Measured RPM: 2580rpm
>Corrected RPM: 2540rpm
>MAP: 1,30ata
>Note that RPM was a bit lower than spec
This might be a difference to German and British procedure, which probably would have required to calculate speed for the specified engine conditions from the data.
To give an idea of that: You'd consider power as linear to rpm and correct the measured speed with the cubic root of the specified to measured rpm ratio. For the above test, you'd get 641 km/h instead of 636 km/h top speed.
This calculation (or data reduction, in British terms) is not entirely accurate, but it seems it was reasoned that for small corrections the error was very small.
For a complete test, you'd also put the engine on the test stand to verify it gave the specified power, and correct any deviations in the same way. If the engine gave more power, you'd even correct downwards :-)
Regards,
Henning (HoHun)
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HoHun,
Generally the error caused by lower RPM is quite neglible up to FTH just as difference between 636km/h and 641km/h. Above FTH lower RPM would also affect MAP (and speed/RAM...) so there the error is more cumulative. As an example, at 10km (or 10,1km CINA) the tested plane reached 552km/h at 0,74ata and in the DB test the DB 605 powered Spitfire V reached about 575km/h at 10km and 0,84ata. Therefore it can be assumed that the FAF tested plane could have done around 560-570km/h at 10km with 2600rpm which is very close to DB and MTT data on Bf 109G and the FTH might had been around 6,6km CINA..
Anyway, all this is pretty much just nittpicking, my point is just that 640 km/h TAS at 10km is pretty much impossible with a standard plane and standard settings.
gripen
edit: corrected overestimated speed.
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Originally posted by gripen
Isegrim,
The critical altitude of the DB 605 given in the specs (5800m at 1,3ata 2600rpm) is with some RAM (about climb speed). See for example spec chart posted above. Quick and dirty estimate for the unrammed FTH of the DB 605A is about 5200m at 1,3ata 2600rpm.
Hate to disagree, but it`s not. ;) Your confusion comes from the DB 605 A power curves, which were printed on standard milimater papers that say it`s 'statisch und dynamisch' power outputs. They say it for all engines... However in case of the 605A`s, it`s only static output, the dynamic outputs are missing from the paper...
http://www.x-plane.org/users/isegrim/Motor/DB605Agraph.jpg
This can be confirmed from the DB 601E power output curves, notice they have the same standard note on the right, but they also give the dynamic pressure gain (staudruck) in the curves themselves, unlike the 605A curves.
(http://www.x-plane.org/users/isegrim/Motor/DB601E-Chart1.jpg)
As you can see, the qouted 1200 PS at 4.8km value is for static output at 0 kg/m2 Staudruck..
Also note that not even that curve chart is free from small typo errors, i.e. 1200 kg / cm2 is quite a pressure gain, eh? ;) (on 601N chart it`s 1200 kg /m2, which is the correct one ).
Studying the 601E dynamic powers vs 109F-4`s VDH (6200m) in flight tests also shows the 109F gained 800 kg / m2 dynamic pressure at full level speed flight, or about 1100 m FTH increase in max. level speed.
Applying the same (in fact it was more because of higher speed of 109G, and larger air intake) gives 5800 + 1100 = 6900m VDH for the 109G (unless if you would like to claim that the 109G would gain a whole 300m only for some mystic reason, 1/3 that of the 109F gained, as it did in the engine swap test MW likes to show. The reason is obvious in his case, though.).
It`s also tells you why the TSAGI`s speed curves are correct. RAM effect as we know decreases the output with fixed s/c ratios, as in the case of the 1st fixed speed on DBs as well. The dynamic pressure is the highest at low levels, so is the power loss; it decreases as altitude increases, so does power increases. Thus it`s not a linear line, but for a rough example, the curve at SL at max. level speed flight is valid for 1200 kg/m2, but at 500m it`s only 1100, at 1000m it`s 1000 etc. The power output varies with varying dynamic gain.
In other words, the decreasing IAS speed w. altitude gives a curved pressure gain curve, which gives a curved power output curve instead of linear, which again gives a curves max. speed curve instead of linear, as all these things interact with each other. In most curves these are simplified however, and shown with a weighted straight line. And that`s why the Soviet curves shapes are accurate.
For MW,
http://www.x-plane.org/users/isegrim/109/climbfinnG-2MT215-13ata.jpg
Climb results obtained in the Finnish tests with Bf 109 G-2 MT 215 at 1.3ata.
at 0m : 21.7 m/sec = 4270 fpm
at 1900m : 24.2 m/sec = 4760 fpm.
Which tells us why Miky didn`t put up this speed graph as well, `cos then he would also have to show the climb results at 30-min reduced power outputs..
Since the DB 605 A developed 1310 PS at 1.3ata, but 1475 at 1.42ata, it`s reasonable to belive that the climb performance at the full 1.42ata rating would be
As a sidenote, the Finn climb tests are in perfect agreement with the dataset of Rechlin and Tsagi for the 109 G-2 at altitude w. 1.3ata. The Rechlin results fell between the two others at low altitude, that`s 21 m/sec or 4133 fpm at 1.3ata reduced power.
edit: The FAF speed tests on Bf 109G-2 were flown the radiators at shut position. [/B]
This exactly means what mm ? Same setting at whole altitude range?
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Hi Gripen,
>Above FTH lower RPM would also affect MAP (and speed/RAM...) so there the error is more cumulative. As an example, at 10km (or 10,1km CINA) the tested plane reached 552km/h at 0,74ata
Hm, my copy of the MT215 graph shows 574 km/h at 10 km.
>Anyway, all this is pretty much just nittpicking, my point is just that 640 km/h TAS at 10km is pretty much impossible with a standard plane and standard settings.
Hm, 640 km/h? The Kennblatt shows only 630 km/h at that altitude.
If I use the FAF aircraft as a basis, applying the rpm correction as outlined above and adding 200 m of ram effect to get to the 6.6 km full throttle height you mention, I get to ca. 610 km/h at 10 km.
The remaining difference to the Kennblatt data is mostly due to the difference in full throttle height (6.6 km vs. 7 km). With a 7 km full throttle height, I'd say 625 km/h @ 10 km would be realistic for the FAF airframe. (Still slower than the Merlin 61 Spitfire IX, of course.)
Regards,
Henning (HoHun)
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Originally posted by gripen
Anyway, all this is pretty much just nittpicking, my point is just that 640 km/h TAS at 10km is pretty much impossible with a standard plane and standard settings.
Could be impossible, but it happened, Gripen. ;) Refer to the TSAGI`s curves (1.42ata).
BTW, a sidenote to the Finn 109 G-2 being tested there. I think I found the clue why it performs well at low levels, but fails to obtain 7000m VDH, or why it performs badly at high altitude.
Look at it`s picture:
(http://www.kolumbus.fi/staga/planes/megerfin2.jpg )
Notice something? Yep, the tailwheel is fully out in level flight . Bf 109G-2s had retractable tailwheel, unless of course the mechanism was disabled in individual cases. Late production aircraft would receive a stronger, but non-retractable tailwheel. There`s a picture in Prien-Rodeike, which shows three 109G-2s in transit flight. The foremost has n/r tailwheel, the other two have their tailwheels retracted.
This caused extra drag and considerable loss of speed : -12 km/h at SL as per German drag docs, and as a rule of thumb, 50% more at VDH, and even more at extreme altitudes like 10km.
The loss of obtainable maximum speed above static VDH would deprieve the plane from a lot of RAM and power, hence the lower speed and lower critical altitude obtained. It would hardly effect climb rates, though, since those being developed at low airspeed.
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Hi Isegrim,
>Refer to the TSAGI`s curves (1.42ata).
Hm, from the climb rates, I'd have thought the Tsagi curves are for 1.3 ata.
>Yep, the tailwheel is fully out in level flight .
From my estimates, I'd say the drag condition of the FAF aircraft was good. Accordingly, I don't think the tailwheel was out. Ram must have been lacking for some other reason.
Regards,
Henning (HoHun)
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Originally posted by HoHun
Hi Isegrim,
>Refer to the TSAGI`s curves (1.42ata).
Hm, from the climb rates, I'd have thought the Tsagi curves are for 1.3 ata.
I believe so, too, I have drawn Rechlin`s, Tsagi`s and the Finn climb tests on the same paper, they match each other above 2000m to an extent of 0.1m/sec ! Simply it could be Tsagi climbed at the 30min setting, but speed runs were done at the 3 min setting - the latter being rather impractical for long climbs.
From my estimates, I'd say the drag condition of the FAF aircraft was good. Accordingly, I don't think the tailwheel was out. Ram must have been lacking for some other reason.
HoHun, look at the picture, it was posted by another member, and it`s the same MT 215 plane, just before in German service. And the tailwheel IS out. ;)
Appearantly, one has only read the report itself, or see pictures of MT 215 in Finn service to be sure. But the tailwheel gives a good all around explanation. The other thing I can think of is perhaps different atmoshpheric conditions in the far North, Recling`s and Tsagi`s test would be done at least 1000 km more to the south...
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Dear Isegrim,
As usual you mixing things to support your agenda. The DB 605 graph contains just one output curve for about climb speed RAM effect, therefore the graph says static and dynamic RAM.This can be easily verified from the several clinb curves of the Bf 109G; at climb critical altitude is around 5800m. Basicly it's your word against the text in the document. and large amount of test data
Regarding the shape of the speed curve, the question is not about what happens below the first FTH but what happens above the first FTH. When the plane reaches the first FTH, the second oil pump of the supercharger starts to work keeping the MAP constant by increasing the RPM of the supercharger by readucing slip. This causes corner to the first FTH. Convex shape of the power curve between first and second FTH is caused by the relative efficiency of the hydraulic coupling which increases when the slip decreases. This is exactly what Hohun allready described above and again it can be verified easily from the performance curves of the DB 601E and the DB 605A as well as from the performance curves of the MT-215. Therefore it can be easily seen that the Russian performance curves are not correct between the first and second FTH. Basicly RTFM.
gripen
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Originally posted by VO101_Isegrim
The foremost has n/r tailwheel, the other two have their tailwheels retracted.
[/B]
errrmmm... they all have their tail wheels out in that pic.
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Originally posted by gripen
Dear Isegrim,
As usual you mixing things to support your agenda.
Yada-yada-yada...
The DB 605 graph contains just one output curve for about climb speed RAM effect, therefore the graph says static and dynamic RAM.
As usual Gripen, you are dead wrong, and escape to primitively parrotting the same misconception of yours. The 605 graph shows the static outputs only, printed on a standard paper. Where`s the evidence that it includes ram effect? No-where. Just as we cannot find any evidence to any of your other claims, because you awfully bad at supporting your own statements (which may be related to the fact they can`t be supported).
This can be easily verified from the several clinb curves of the Bf 109G; at climb critical altitude is around 5800m. Basicly it's your word against the text in the document. and large amount of test data
Nope, sorry Grippy, it`s only you alone who invented that 'German power curves include a small dynamic head', now being changed to 'only the 605 curves include a small dynamic head'. Another spin in it... It`s unsupported, the document doesn`t show the any Staudruck at all, something very strange isn`t it?
Yeah of course, Grippy, any precise engineer would do a engine curve for dynamic output, and would say to you, 'Hey, here`s a graph I made, it gives you dynamic output somewhere between 1 kg/m2 and 5000 kg/m2, I will leave it to you to find out exactly'
But so far showed no evidence of it. It`s as usual, the case when Gripen wants to look like the local smartass who knows everything better than anybody, including the German engineers who drew those graphs. Then he goes into parrot mode, and keeps repeating it.
I will believe sooner that it`s a single man`s distorted idea, being invented to support his other distorted ideas.
Therefore it can be easily seen that the Russian performance curves are not correct between the first and second FTH. Basicly RTFM.
I perceive sadly that your lack the intellectual capacity to understand something very simple.
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Originally posted by thrila
errrmmm... they all have their tail wheels out in that pic.
If you noticed I referred to a picture in Prien-Rodeike`s book, not this picture of the finnish craft.
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Hmmm, looking better into Isengrims comparisons:
(adding a few more lines)
The Spitfire Isengrim picked is the one I have very little info about, it is the Mk IX LF JL 165.
"Similiar joke comparisions can be made, let`s compare "
Mk VIII with 25 boost
Mk IXLF JL 165 at +18lbs and
Mk IX HF with 18 boost
vs.
Tsagi`s 109 G-2, shall we:
SL speed :
Mk VIII 582 km/h
109G-2 : 530 km/h
Mk IX LF : 515 km/h
Mk IX HF 524 km/h
at altitude :
Mk VIII 651 km/h at 6160. (also at 18 boost)
109 G-2 : 665 km/h at 7000 m.
Mk IX LF : 624 km/h 5900 m.
(the other LF fighter does 661 km at 6405 m)
Mk IX HF 664 km/h at 8113 m, or even 654 at 9150 m. The one with the Merlin 66 does 668 km at 8479 m.
Gee, aint that Spitfire Mk IX LF a good deal slower ? Let`s look at the really high altitude:
at 9100m :
109G-2 : 650 km/h
Mk IX LF : 611 km/h
Mk IX HF 654 km/h
Getting really high, 11895m, the Spitty still does 593 km/h
"Spit gets the low end of stick, as usual. "
Well,the low end of the stick goes to your presentation of data Isengrim, because you handpicked the worst spitty.
It looks to me as the Spitties were good at the altitudes they were designed for, cruising well over stall at 43K as well.....
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Dear Isegrim,
For the evidence please look at the DB 605 graph, the text says directly that graph include static and dynamic RAM. It does not matter what ever paper it is printed. Look at the climb charts of the Bf 109G with the DB 605A (1,3ata 2600rpm) and the FTH in climb is allways around 5800m.Try to live with that.
The shape of the Bf 109G performance curve between first and second FTH is caused by power output of the engine, not by RAM effect. Try to live with that.
gripen
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Dear Grippen,
if the DB 605A power curve includes the ram effect already, then it must be the case that SL power output was higher than we know, ie. 1475 PS. This is logical since ram reduces power output below FTH on fixed s/c speeds, as evidenced on the 601E curves which are w/o doubt show both dynamic and static positions.
So how much the DB 605A develops in static at SL? 1500-1550 PS ? Curious, why no mentioning of such figures in any document, nowhere! Also interesting, why the Germans would take an exception with the 605A, since by default all of their engine power output curves refer to static power. The DB 605A must have been a very, very special engine to be an exception from the rule... :rolleyes:
Perhaps somebody is just wrong... in many things.
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Dear Isegrim,
Ah, now you are starting to understand. My quick and dirty estimate is that the DB 605A would produce around 1490hp sea level without dynamic RAM.
I don't know why the Germans invented output graphs with dynamic and static RAM.
HoHun,
I'm quoting directly the performance table which lists values:
h: 10000m
h cina: 10100m
density: 0,419kg/m3
IAS: 320km/h
Corrected: 566km/h
Comp. Cor: 552km/h
RPMi: 2580
RPM: 2540
MAP: 0,74ata
Regarding (about) 640km/h at 10km claim, I can't measure Russian chart any better, do you?
gripen
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Originally posted by gripen
Dear Isegrim,
Ah, now you are starting to understand. My quick and dirty estimate is that the DB 605A would produce around 1490hp sea level without dynamic RAM.
gripen
Great finding, Gripen. Now, you need to prove this. When you are done with that, prove also those half a dozen other claims you made here.
Until then, it remains an isolated opinion. :cool:
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Hi Isegrim,
>Simply it could be Tsagi climbed at the 30min setting, but speed runs were done at the 3 min setting - the latter being rather impractical for long climbs.
Hm. I'm not sure.
The Tsagi charts have several sets of numbers.
Pic. 1 Vmax: Me 109G-4, 650 km/h @ 7 km
Pic. 2 Vmax: Me 109G-2, 670 km/h @ 7 km
JPG15, Vmax: Me 109G-4, 650 km/h @ 7 km
1941 - 1943 Vmax: Me 109G-2 (tre...), 650 km/h @7 km
JPG21 Vmax: Me 109G-2 (tre...), 670 km/h @ 7 km
which seems to be a matching pair with
Pic.2 Vy: Me 109G-2 (tre ...), ca. 21 m/s peak climb rate
The Russian term in brackets which I'm unable to read might provide an explanation :-)
>HoHun, look at the picture, it was posted by another member, and it`s the same MT 215 plane, just before in German service. And the tailwheel IS out. ;)
Oops, missed that it was the very same plane. How can you tell?
Regards,
Henning (HoHun)
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Hi Gripen,
>I'm quoting directly the performance table which lists values:
Roger that. I was using the FAF aircraft as a basis to calculate performance at 10 km for 6.6 km and 7 km full throttle height, getting 610 km/h and 625 km/h respectively. (Note that is for corrected engine rpm.)
>Regarding (about) 640km/h at 10km claim, I can't measure Russian chart any better, do you?
Ah, so the source was the Russian chart. Well, if that was for 2800 rpm, 640 km/h should be no problem. Maybe we can find someone to translate the Russian caption for us :-)
Regards,
Henning (HoHun)
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Hope this help...
(http://www.onpoi.net/ah/pics/users/286_1085249000_109g2climb.jpg)
The Russian term in brackets which I'm unable to read might provide an explanation
Did you mean that (tre) ?
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Hi Voodoo,
>Did you mean that (tre) ?
Roger! Thanks a lot! :-)
I had assumed the term referred to the power setting, so it's good to realize that it actually describes the weapon configuration :-)
Regards,
Henning (HoHun)
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Dear Isegrim,
Maybe you might want to do a bit of brain training, so look at the Daimler-Benz test on the DB 605 powered Spitfire climb chart. Now look at which altitude the planes (Spitfire and reference Bf 109) reached it's second FTH. Think why the FTH in the climb (for 1,3ata 2600rpm) is about same as in the output chart in the manual? After that it's up to you to decide if the DB 605A failed to reach claimed performance even in the manufacturer's own test or if the manual chart contains some dynamic RAM (as the text in the manual actually says).
HoHun,
Well, my estimate for the MT-215 performance at 10km with 1,3ata and corrected 2600rpm is (as mentioned above) 560-570km/h (that naturally means allready 6,6km FTH, no need to correct that twice, right?). Now let's ad 10km/h for the tailwheel inside to make Isegrim happy. So now we have a say 580km/h MT-215 at 10km which I believe is a good estimate for a good Bf 109G-2 at 10km and 1,3ata 2600rpm. At FTH 6,6km this plane would do about say 655km/h, tailwheel down something else.
Then lets assume (without good evidence but because you announced that you won't accept lower values) that the FTH was actually 7km to make you happy. Then we could have a plane which would do say 665km/h at FTH and at 10km it would do say 20km/h more ie 600km/h.
And last lets try to figure out if the 640km/h was "no problem" with1,42ata 2800rpm. The DB 605A FTH with both power settings in the MTT charts appear remain same so lets assume that our super Bf 109G-2 had FTH 7000m. The speed increase at FTH is just 10km/h in the MTT docs but because we are allready speculative, lets assume that it was actually 20km/h so 685km/h at 7km.
Then to the 10km, now we can use calculated AS data from the MTT specs. At 1,3ata 2600rpm the spec (3320kg) is 648km/h at 8,8km and at 1,42ata 2800rpm the spec is 660km/h at 9km (note that the AS had a different propeller) . Damn, just 12km/h. But what the hell, lets assume that our super 109 actually could gain 30km/h with increased RPM despite what ever is the blade tip speed. So now we have a 630km/h Bf 109G-2 at 10km. Oléé...
Well, you might have a idea how realistic is that 640km/h claim.
gripen
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Hi Gripen,
>happy. Then we could have a plane which would do say 665km/h at FTH and at 10km it would do say 20km/h more ie 600km/h.
Hm. From your presentation I'm not sure that you actually calculated anything. Let me point out that I didn't just dream up some numbers, but actually went into some detail to arrive at realistic figures.
Regards,
Henning (HoHun)
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Whatever the results may be, the 109G2 will have problems with a spitty at optimized alt :D
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HoHun,
Well, originally I just calculated quick and dirty that 2,3% difference in the RPM would result about as large difference in the FTH and some what more at 10km. As you can see I actually edited post after thinking the blade tip speed; estimate was too high.
For unknown reason you corrected the allready wrong number (574km/h at 10km) twice by adding 200m after quick and dirty correction and ended to the so called "realistic figures". IMHO a bit of sarcasm is fully justified.
Discussion might be a bit easier if you won't seal your opinions by making statements like that you won't accept anything less than 650km/h at 7km despite some data actually proves something else.
gripen
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Hi Gripen,
>For unknown reason you corrected the allready wrong number (574km/h at 10km) twice by adding 200m after quick and dirty correction and ended to the so called "realistic figures". IMHO a bit of sarcasm is fully justified.
You're underestimating the complexity of my calculations :-) I didn't use the 10 km value, but the 6.4 km value, corrected to 541 km/h, as a basis, and used the engine graph to establish a speed curve for the entire altitude range for comparison to the Finnish test. Then I adjusted the power curve to the 7 km full throttle height used by the German Kennblatt as well as by the Russian graphs to see what speeds would result - again over the entire altitude range.
>Discussion might be a bit easier if you won't seal your opinions by making statements like that you won't accept anything less than 650km/h at 7km despite some data actually proves something else.
Well, ironically I was about the last one here to throw my hat into the ring by posting a speed figure :-) 650 km/h @ 7 km still is a realistic figure, easily met by the Finnish test aircraft if its engine were good for a full throttle height of 7 km.
Regards,
Henning (HoHun)
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Hi Angus,
>Whatever the results may be, the 109G2 will have problems with a spitty at optimized alt :D
To get back on the original discussion, I believe we all agree that looking for "The World's Best Fighter" in 1942, the only types worth talking about are the Me 109G, the Spitfire IX and the Fw 190A - with altitude being the decisive factor?
I still think "The Gustav was obsolete when it entered production" is an example for extraordinarily poor powers of perception :-)
Regards,
Henning (HoHun)
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I agree there.
The 109 airframe was quite incredible, and basically the 109 did not get obsolete in WW2.
Funny how diferent, and yet not different the 109 and Spitty are, - both designed in almost the same time ;)
My vote for the world best fighter in Spring of 1943 yet goes to the Spitty :D
(With the 109 really nibbling at its heels)
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HoHun,
Sorry if got a wrong impression but you wrote it so that I understood that you made FTH correction twice. Now I have calculated a bit more than quick and dirty stuff but there appear to be no big differences.
My approach is quite simplified but it should be accurate enough. As before I'm assuming that the RPM difference is about directly relative at FTH, using V-1710 charts from the "Vee's for Victory" and the DB 605 chart this appear to be quite accurate for single stage engine at around 6-7km. The difference 2540/2600 should give 2,3% increase in the FTH, 6420m CINA would result FTH 6571m CINA ie about 151m increase. As for comparison 2800rpm would result 7077m CINA (naturally for 1,3ata) ie 657m increase in the FTH (2540/2800). This fits quite well to the DB 605 manual chart, at climb speed increasing RPM from 2600 to 2800 results around 600m. The DB 605 chart also show that I was wrong by estimating that the difference should be bit more at 10km, it actually is less, about 300m for 2600->2800 and therefore 90m for 2540->2600, my mistake (that's actually the reason why the very first estimate for 10km was too high). The speed at the new 2600rpm FTH 6571m CINA would be about 645km/h.
So the speed was 552km/h at 10100m CINA, and 610 km/h at 9110m CINA. Using linear estimate the speed at 10000m CINA would be 558km/h. Now we can take that 90m FTH increase (for 2540/2600) and by looking downwards we can estimate speed (without rpm correction) by taking linear estimate for 9910m CINA and that results 563km/h at 2600rpm, 2800rpm would result 575km/h. Now we can ad rpm correction 5km/h for 2600rpm and say 15km/h for 2800rpm (probably optimistic due to propeller tip speed as calculated AS values show). So now we have estimates for 10km, 568km/h at 2600rpm and 590km/h at 2800rpm. To make Isegrim happy we can took tailwheel in so then we have 578km/h and 600km/h which I believe are pretty good and well founded estimates.
Regarding your argument that the MT-215 with 7km FTH engine would met figures; I calculated 615km/h at 10km tail wheel down and 625km/h up but maybe with 8km FTH engine it would do 640km/h, right? Well, can't avoid sarcasm with that kind of arguments, sorry.
gripen
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Hi Gripen,
>taking linear estimate for 9910m CINA and that results 563km/h at 2600rpm
Does that mean your method is based on calculating a speed difference for altitude A and apply it to altitude B? As air density varies with altitude, that would be quite inaccurate.
Regards,
Henning (HoHun)
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HoHun,
Yes, but I have no values for higher altitudes, besides the altitude difference is small even in the case of the 2600->2800rpm. Alternatively I can use DB data on the 109G (Spitfire with the DB 605) between 9350-10350m (the average between 9700-10000m) which means that linear drop of the speed should be in the right ball park. That would result again 600km/h at 2800rpm. There should be no large errors.
IMHO the propeller efficiency would cause larger error. At certain point increasing the RPM would not increase speed.
gripen
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Hi Gripen,
>IMHO the propeller efficiency would cause larger error. At certain point increasing the RPM would not increase speed.
Good hint, I had a typo in my data and was calculating with the wrong rpm. At 10 km, that makes a 15 km/h difference.
However, my calculations still indicate 627.5 km/h for a 6.9 km full throttle height, tailwheel-up Bf 109G-2 at 2800 rpm/1.42 ata.
That's just 12.5 km/h off the 640 km/h mark - still good enough :-)
I am not entirely convinced the MT215 was in fact tested in tailwheel-down configuration, though, and if it wasn't, that might require a downward adjustment of my figure.
Regards,
Henning (HoHun)
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HoHun,
Generally if we have the right estimate for the rate of the speed change due to decreasing MAP at given altitude (above FTH) then above system should be quite accurate for small MAP changes. In fact it gives fairly good estimate for speed at 10km with the DB 605AS engine given the output difference.
Assuming 6,9km FTH MT-215 data gives 608km/h and DB data gives 607km/h. Overall my opinion is that 640km/h at 10km might be possible but at very much lightened condition, "ohne waffen und munition, ohne panzerung", airframe cleaned (antennas etc. removed) and polished.
Besides, 6700m FTH in high speed for DB 605A is well documented so why not use it?
The MT-215 had fixed tailwheel, it's mentioned in the report.
gripen
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Hi Gripen,
I discovered that I entered the greater weight of the G-5/AS for my G-2 calculations. Using 3023 kg as for the Soviet test aircraft of course gives better high altitude performance.
>The MT-215 had fixed tailwheel, it's mentioned in the report.
OK, thanks! :-)
>Generally if we have the right estimate for the rate of the speed change due to decreasing MAP at given altitude (above FTH) ...
That's exactly where I have doubts. The FAF aircraft shows an almost linear speed drop there where it should be a convex curve. Extrapolated to 11 km, the FAF data would be optimistic.
>Besides, 6700m FTH in high speed for DB 605A is well documented so why not use it?
Pick your choice:
FTH 6.4 km, rpm corrected: 641 km/h @ FTH, 591 km/h @ 10 km
FTH 6.7 km: 646 km/h @ FTH, 602 km/h @ 10 km
FTH 6.6 km, 1.42 ata/2800 rpm: 652 km/h @ FTH, 610 km/h @ 10 km
FTH 7.0 km: 652 km/h @ FTH, 613 km/h @ 10 km
FTH 6.9 km, 1.42 ata/2800 rpm: 658 km/h @ FTH, 620 km/h @ 10 km
FTH 6.9 km, 1.42 ata/2800 rpm, retractable tailwheel: 667 km/h @ FTH, 630 km/h @ 10 km
Regards,
Henning (HoHun)
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HoHun,
The MT-215 data set contains just few points and using values from 9110m and 10100m CINA, the speed decreases 58,6km/h per 1000m. As for comparison even choosing 10000m and 11000m from the DB dataset results just 30km/h per 1000m and 606km/h at 2800rpm. To reach that 640km/h, the speed decrease per 1000m should be more than 100km/h. Because the altitude change for correction is max 390m, the linear estimate gives certainly good enough result.
The weight difference between the G-2 and G-5/AS proto is about 170kg. According to MTT data, 170kg difference causes about 4-5km/h at FTH, somewhat more at 10km.
May I ask which certainly real life measured and documented data set supports more than 6700m FTH?
gripen
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Originally posted by gripen
Besides, 6700m FTH in high speed for DB 605A is well documented so why not use it?
:rofl :rofl :rofl :rofl :rofl
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Hi Gripen,
>Because the altitude change for correction is max 390m, the linear estimate gives certainly good enough result.
Well, have a look at the speeds for the last example to see the effect of a realistic power curve (read the lower-case "v" as down arrow :-)
6900 m: 667 km/h
v almost unchanged
7000 m: 667 km/h
v -8 km/h
8000 m: 659 km/h
v -11 km/h
9000 m: 648 km/h
v -18 km/h
10000 m: 630 km/h
v -28 km/h
11000 m: 602 km/h
It's the increasing speed gradient that makes small changes in full throttle height translate into surprisingly large changes in speed at altitude.
>The weight difference between the G-2 and G-5/AS proto is about 170kg. According to MTT data, 170kg difference causes about 4-5km/h at FTH, somewhat more at 10km.
I'm using 3023 kg now. Is that OK?
>May I ask which certainly real life measured and documented data set supports more than 6700m FTH?
Well, as the Soviets captured and tested W.-Nr. 14513, a clean Me 109G-2, I'd assume their test is based on real-life tests, too. The Kennblatt also supports a 7 km altitude.
In fact, the gain in dynamic pressure from 667 km/h @ 7 km would be 10.1 kPa, which would suffice to get an intake pressure equivalent to 5.4 km altitude. Though not all of the pressure can be realized, I think a typical pressure recovery value would be around 90%, which would still be good enough for a 7 km full throttle height. (Just from what I read on the net - 90% might be wrong.)
An explanation for the difference in observed full throttle heights is that ram pressure increases with the square of speed. For example, the G-6/AS comparison test you sent me states a full pressure height of 6.6 km @ 630 km/h, but at around 670 km/h, you might get 200 m more than that due to the higher speed.
(I don't consider 7 km the final word anyway, it's just a working hypothesis.)
Regards,
Henning (HoHun)
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HoHun,
Basicly I'm just calculating quick and dirty what would be the speed increase at given altitude with data sets which certainly are real. We don't know what's the exact output difference between 2600and 2800rpm at 10km with high speed RAM but we know from the DB output curve that at 2800rpm the DB 605A did same output about 300m higher than 2600rpm at around 10km and at climb speed. By choosing data sets which allready support your agenda, you certainly get results you want.
Now if you just can prove that the Russian test data and Kennblatt data are real (or realistic), that's why I have been asking for documentation. Another way would be real output data with RAM at 10km.
Regarding weight, 3020+170=3190= weight of the tested G-5/AS. I have no problem to accept anything between say 3000-3100kg for the G-2, it won't change the fact that at 10km the DB 605AS did at least 100hp more at 2600rpm than the DB 605A at 2800rpm and the AS plane had the propeller optimized for high altitude.
Because the measured speed of the AS and claimed speed of the G-2 are about the same, the RAM effect can't be used to support your agenda.
gripen
edit: Corrected hp value
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Hi Gripen,
>Basicly I'm just calculating quick and dirty what would be the speed increase at given altitude with data sets which certainly are real.
Well, and I'm calculating slowly and (kind of) cleanly the speed at a given altitude from power curves that certainly are real.
>it won't change the fact that at 10km the DB 605AS did at least 100hp more at 2600rpm than the DB 605A at 2800rpm and the AS plane had the propeller optimized for high altitude.
If you have the power curve for the DB605AS, I could plug it in and see what happens.
>Because the measured speed of the AS and claimed speed of the G-2 are about the same, the RAM effect can't be used to support your agenda.
Let's cut the "agenda" nonsense and discuss this like professionals, OK? As I pointed out, 7 km full throttle height is only a working hypothesis for me.
With regard to the comparison: From different DB605A-engined aircraft, you should expect a higher full throttle height for the faster aircraft, and that the difference can be in the same order of magnitude as the one we're talking about.
(Note that the tested Me 109G-6/AS had a fixed tail wheel, MG131 nose guns and the enlarged cowl of the AS-engined Messerschmitt, which along with the weight increase would deteriorate its altitude performance somewhat. If you have an AS-power curve, I could plug it in to see what happens.)
Regards,
Henning (HoHun)
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HoHun,
The DB605D should have a very similar power output at 10km as the DB 605AS. The output difference between 2600 and 2800rpm should be around 50ps at around 10km. The tested output in climb for the DB605 AS at 2600rpm and 10km was 965ps according to Valtonen (calculated 930ps).
There might be 100-200m differences in the FTH at around FTH height, at 10km these differences are half and I allready used 390m difference to minimize this error in my quick and dirty estimate. I'm still wondering why don't you use the FTHs from the documented data.
Regarding your supposed agenda; I don't know what else I should think if you continously use higher than documented FTH for you hypothesis and base your calculations on undocumented and unlogical data sets.
gripen
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Hi Gripen,
>Regarding your supposed agenda; I don't know what else I should think if you continously use higher than documented FTH for you hypothesis and base your calculations on undocumented and unlogical data sets.
Whether these data sets are unlogical has yet to be determined, for example by discussing the results from calculations based on these data sets. It's exactly the lack of (detailed) documentation makes computation an indispensable analysis tool here.
Above, I have provided Me 109 calculations for full throttle heights of 6.4, 6.6, 6.7, 6.9 and 7.0 km.
Since you're aware that full throttle height depends on speed, you should really provide documented full throttle heights and corresponding speed figures for comparison.
A telltale sign for arguing with a hidden agenda is the attempt to avoid rational analysis. That's not my approach, and I don't think it's your approach either.
So, how do the documented Me 109 tests stack up against my calculations?
Regards,
Henning (HoHun)
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HoHun,
To me Russian data is clearly unlogical; there seems to be no consensus about the used engine settings, results show od shape of the speed curve, at low altitude speed matches well MT-215 data , at high altitude speed matches the G-5/AS. The KennBlatt (at least the one Isegrim posted) says 6,4km FTH at high speed flight while the data set indicates something else.
I have provided you several measured FTHs. The MTT "Baureihen" data (various loadings) shows following values for various speeds and FTH at 1,3ata 2600rpm:
652km/h 6,7km
636km/h 6,6km
608km/h 6,5km
595km/h 6,4km
Note that these are just examples from the long list. If compared to MT-215, these are higher. Erla data shows an average FTH 6,7km for their planes (the problem with that data is that MTT planes are allways worse in the Erla data, go figure).
All I can say about your calculations is that these appear to show at least 20km/h faster speeds at 10km than real life data indicates. At climb speed the DB specs give 740ps 2600rpm and 790ps 2800rpm at 10km. At high speed the output difference can't be much more.
I have no idea how have you done your complex calculations but 30-40km/h speed increase with 50-60ps output increase is very unlikely.
gripen
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Hi Gripen,
>The MTT "Baureihen" data (various loadings) shows following values for various speeds and FTH at 1,3ata 2600rpm:
The resulting pressures (static + dynamic):
670 km/h @ 6,9 km: 52,0 kPa <- Basis for my calculation, 2800 rpm
----
652 km/h @ 6,7 km: 53,0 kPa
636 km/h @ 6,6 km: 53,2 kPa
608 km/h @ 6,5 km: 53,1 kPa
595 km/h @ 6,4 km: 53,4 kPa
----
422 km/h @ 5,8 km: 53,2 kPa <- Calculated, 2600 rpm?
000 km/h @ 5,1 km: 53,2 kPa <- Calculated, 2600 rpm?
(This is without considering any losses to the dynamic pressure.)
It's interesting that the values are subject to some variation, and the slowest plane ends up with the higher pressure. I'd have suspected the opposite.
From this comparison, I'd say it doesn't look like 6.9 km full throttle height could be reached even with the help of ram effect. However, I'm not sure at which rpm the figures you quoted were achieved. Were they all for 2600 rpm?
Regards,
Henning (HoHun)
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HoHun,
The DB 605 power chart is a good starting point for the analysis; at climb speed the FTH for 1,3ata 2600rpm is 5800m and for 1,42ata 2800rpm it is 5700m. Generally I avoid calculating RAM effect despite it's relatively simple using standard conditions and bernoul's law; the engine is a dynamic system and calculation assumes static system.
The MTT data gives allways same high speed FTH for both power settings in the case of the DB 605A. In the case of the AS FTH for 1,42ata 2800rpm is somewhat higher.
I'm still wondering why you want to use that 6900m despite nothing real life tested supports it? Kennblatt says actually 6400m as noted above and listed values are obiviouysly calculated. The Russian data set seems to be for 1,3ata at low altitude (or drag configuration of the plane was very bad). At high altitude it's out of reality.
I don't know exactly how you have build your model, you described it as:
"You're underestimating the complexity of my calculations :-) I didn't use the 10 km value, but the 6.4 km value, corrected to 541 km/h, as a basis, and used the engine graph to establish a speed curve for the entire altitude range for comparison to the Finnish test. Then I adjusted the power curve to the 7 km full throttle height used by the German Kennblatt as well as by the Russian graphs to see what speeds would result - again over the entire altitude range. "
If I understand this correctly, your model has a built in agenda; you are assuming that increased FTH results automaticly performance claimed by Kenblatt and Russian test.
gripen
edit: the values were all for 1,3ata 2600rpm
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Hi Gripen,
Since I'm convinced you'll understand me if you pause to think about it for a moment, here's a description of my approach:
I'm currently calculating data for a Me 109G-2 based on FAF data, with drag reduced so that sea level speed increases by 10 km/h, for an engine performing like a DB605A running at 2800 rpm/1.42 ata with a full throttle height of 6.9 km. (I could use 7 km, too - I actually dropped to 6.9 km by accident when I switched from 2600 rpm/1.3 ata to 2800 rpm/1.42 ata.)
That I'm calculating this data doesn't mean that I consider it to be representative for a real Me 109G-2. It only means that working from limited data, I consider a 7 km full throttle height plausible enough to think it deserves thorough analysis.
I'm not going to make any statement about the likely outcome of this analysis now. The outcome should be the result of the analysis, and not be determined by what I think in advance it might be. I'm afraid that currently, your idea of what the outcome should be is influencing your reception of my posts, which would be regrettable because I need your help for an unbiased analysis :-)
You don't need to fear any bias from me: For example, if you look at my above post, I provided data showing that the 6.9 km/670 km/h case misses about 1.2 kPa in intake pressure, which means that the 6.9 km full throttle height is missed by about 200 m. If I were following a hidden agenda, I'd hardly have provided the data for you because I know that you're aware of the implications. To help "your" case even further, I could point out that as your data was for 2600 rpm and the 2800 rpm full throttle height requires an even higher intake pressure, leading to an even greater pressure gap.
So now it would be interesting to see the Erla data (with the same full throttle speed/altitude combinations). If it's better than the Messerschmitt data but still worse than the Russian data, that obviously would undermine the 6.9 km (or 7.0 km) full throttle height even further. If it's identical to the Russian data, one might wonder if they actually got their data from Erla ...
So let's talk about airplanes again and not about agendas - I could get to the heart of the matter much quicker if I wouldn't have to type three disclaimer paragraphs for each post I write ;-)
Regards,
Henning (HoHun)
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Could one of you guys define full throttle hieght? Is that the same as critical alt?
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Hi Seeker,
>Could one of you guys define full throttle hieght? Is that the same as critical alt?
Full throttle height is the lowest altitude at which the engine can be run with the throttle fully open without exceeding the specified operation parameters.
I believe it's indeed the same as critical altitude :-)
Regards,
Henning (HoHun)
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Originally posted by HoHun
Hi Seeker,
Full throttle height is the lowest altitude at which the engine can be run with the throttle fully open without exceeding the specified operation parameters.
I understand every word; and yet not a bit of it :)
Do you mean that at X feet; the oxygen content is such that one can open the throttle and not over rev the engine? I would have thought that's a very subjective criterion; as engine load must come in to play?
(so I suspect I really don't understand...)
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I thought "full throttle height" was the lowest altitude were you could run the engine at full power, while "critical altitude" was the highest altitude the engine could produce full power.
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HoHun,
Well, I still can't see the reason why you want to use 6900m FTH for 1,42ata 2800rpm? The MAP is just a indicator how much air (oxygen) the engine gets to the cylinders to burn fuel and at 1,42ata 2800rpm the DB 605 needed more air (kg/s) to produce rated power. This is why the FTH at climb speed decreases from 5800m to 5700m when 1,42ata 2800rpm is used. At high speed the increased output naturally results higher top speed and more RAM balancing the situation. Nothing in the MTT data indicates that the FTH for the 1,42ata 2800rpm would have been 200m higher than in the case of the 1,3ata 2600rpm. The MTT data on G-6 gives 6600m FTH for both settings in the case of the G-2 that means 6700m for both.
The Erla data set is just a set of top speed points which the manufacturer claims to had been reached at 1,3ata 2600rpm (3080kg, radiator flaps at 120mm ???).The set contains 15 points of which 11 are below 6700m the average being 646km/h at 6700m.The highest point is 656km/h at 6950m. The reference MTT point is just 626km/h at 6300m. Erla and MTT were competing for RLM orders, therefore this dataset must be taken with grain and salt; in the Erla data their planes were allways up to or near the specs and the calculated spec was 660km/h at 7000m (actually they calculated another average excluding three worst points). Due to the nature of the Erla set, it's obivious that this was not used by Russians.
Overall I don't see much sense to calculate performance with reduced drag and over estimated FTH . But it's up to you how to spend your time.
gripen
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Gripen if you have the chart under your eyes you'll notice that Volldruckhöhe is given as 7000m in this chart. But indeed it's not easy to make calculation based on this chart based of such a few number of points.
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Butch2k,
Well, the FTH given with the triangle is calculated, none of the planes actually reached it the average being 6700m. The reason that the one Erla built almost reached it, is most likely the same why the MT-215 performed slightly below average at high altitude ie the engine did not run at specified rpm. In the case of the MT-215 the engine run at 2540rpm, in the case of the that Erla plane, the engine probably run at higher rpm than 2600. By looking the DB 605A chart you can see that at 1,3ata and 2800rpm, the high speed FTH would be around 7,1-7,2km.
Overall the MTT data should be taken with quite strict source critic; as an example you have probably seen a Datenblatt dated 12.5.42 which claims 7,5km FTH for steig- und kampflleistung and speed 707km/h for that altitude, the same paper gives 732km/h at 7,6km at Start- und Nottleistung.
gripen
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Hi Seeker,
>Do you mean that at X feet; the oxygen content is such that one can open the throttle and not over rev the engine?
Engine speed was actually limited by the propeller, but you could open the throttle fully without overstressing the engine at full throttle height.
Regards,
Henning (HoHun)
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Hi GScholz,
>I thought "full throttle height" was the lowest altitude were you could run the engine at full power, while "critical altitude" was the highest altitude the engine could produce full power.
Ideally, these two would coincede :-) However, the definition of "critical altitude" depends on the definition of "full power", which might be an idealized term itself.
For example, turbo-supercharged engines in WW2 seem to have been rated at constant power over altitude while they actually gave slightly parabolic power over altitude. At critical altitue, they actually didn't yield full power any more.
Regards,
Henning (HoHun)
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Hi Butch,
>But indeed it's not easy to make calculation based on this chart based of such a few number of points.
Well, I only need a single point :-)
Here's a comparison graph of the Finish test data with the data I calculated from the engine graph (3023 kg, 2540 rpm, 1.3 ata).
http://www.x-plane.org/users/hohun/me109g-2.jpg
As you can see, I get a very good fit, so my model is sane. The difference at low altitude obviously is not due to modelling differences, but due to the Finnish engine performing differently from the reference engine. (Looks like the reference engine had a higher low-altitude supercharger speed.)
Above full throttle height, my graph actually looks more realistic than the FAF test data because the latter features a linear shape where it should realistically be slightly convex, like my calculated shape. I consider that a minor difference, though.
(Any small imperfections in the smoothness of my graphs are due to linear interpolations between tabulated values without any deeper physical meaning :-)
Regards,
Henning (HoHun)
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Originally posted by HoHun
Hi Seeker,
>Do you mean that at X feet; the oxygen content is such that one can open the throttle and not over rev the engine?
Engine speed was actually limited by the propeller, but you could open the throttle fully without overstressing the engine at full throttle height.
Regards,
Henning (HoHun)
Thx for trying; but I still don't get it! :-)
Or rather; I'm forming an idea; but you guys are so anal over definitions I want to be sure I've got this right (back ground: I'm trying to understand these unfamiliar concepts as a two stroke motor cycle tuner)....
of course RPM is goverend by load ; if the load is too great; the mill'll stop no matter what chemicals you're pouring into it. That's exactly why the terms you guys are using confuses me. When you say: "open the throttle fully without overstressing the engine at full throttle height." I read that to say:
Engine X has a safe operating limit of y inches of mercury (or lbs/sqft boost pressure). This I understand; as it's a measure of how hard the engine is allowed to suck (don't giggle, we're talking all kinds of motors; not just LW....).
I don't see where alt comes into it. (or rather; I understand how atmospheric pressure has an effect; just not in these definitions/terms)
I'd really like to get a grip on this. I understand 90% of what you're saying; but I'm seeing it from a sea level perspective; I'm not used to adding alt into the equation.
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Engine X has a safe operating limit of y inches of mercury (or lbs/sqft boost pressure). This I understand; as it's a measure of how hard the engine is allowed to suck (don't giggle, we're talking all kinds of motors; not just LW....).
I don't see where alt comes into it. (or rather; I understand how atmospheric pressure has an effect; just not in these definitions/terms)
A geared supercharger is directly related to engine speed. That means it turns at the same rpm regardless of altitude.
An engine has a max allowable manifold pressure, say 60". If the supercharger is geared so that it can deliver 60" at 20,000ft, it can deliver a lot more at low altitude where the air is thinner.
As you can't adjust the supercharger speed, you close the throttle to restrict the manifold pressure getting into the engine. As altitude climbs, the supercharger is delivering less pressure, so the throttle can be opened gradually. When you reach full throttle height or critical altitude, the supercharger is able to deliver exactly the allowed manifold pressure, and no more, so the throttle no longer has to be closed.
Above that height, the supercharger can't deliver enough pressure, so the throttle remains fully open.
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A new article serie just started in the "Suomen Ilmailuhistoriallinen Lehti" (a Finnish aviation history magazine). It's about the performance of the WWII piston engined fighter planes and the Bf 109G is used as a example in this serie. Author is Jukka Raunio who has previously written "lentäjän Näkökulma" book serie. The first part discuss about atmosphere and later parts will discuss propellers, super chargers, various performance aspects etc. It's written in Finnish.
gripen
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Hi Gripen,
>The set contains 15 points of which 11 are below 6700m the average being 646km/h at 6700m.The highest point is 656km/h at 6950m. The reference MTT point is just 626km/h at 6300m.
OK. I've now assumed that the 5.8 km full throttle height is given for climb speed (374 km/h true for the Me 109G-2), and used this to calibrate the ram efficiency which I get as 86.8%.
This leads to the following values for the four data sets that make the tighest group:
652 km/h @ 6,7 km: 51,6 kPa
646 km/h @ 6,7 km: 51,5 kPa
636 km/h @ 6,6 km: 51,9 kPa
608 km/h @ 6,5 km: 51,9 kPa
This gives an average of 51.72 kPa for full pressure for 2600 rpm/1.30 ata.
Judging from the 100 m difference in full throttle height to 2800 rpm/1.42 ata, this would require 52.4 kPa pressure for the higher power setting.
This value would make a Me 109G-2 (3032 kg, retractable tail wheel, 1.42 ata/2800 rpm) with the following data possible:
662 km/h @ 06.62 km
620 km/h @ 10.00 km
Since this is based on an improved foundation thanks to the data you provided, would you agree that this finally is a realistic estimate?
Regards,
Henning (HoHun)
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HoHun,
Now your estimate for the FTH sounds to at right ball park ie about 15km/h (2,6%) increase for 100ps (8,4%) output increase (might be still at optimistic side).
But your estimate for 10000m seems to be still quite strange ie about 40km/h (6,9%) increase for about 75ps (9,6%) output increase. I have calculated output increase assuming about 450km/h climb speed RAM and standard atmosprehe.
Note that this approach does not count propeller efficiency, which certainly is a signifigant factor at 10000m. The article serie mentioned above will contain propeller efficiency charts for the Bf 109G (I'm not the author but I have collected some data for him and I have seen a work in progress version of the article). My original approach using simple estimate for rate of the speed change actually counts propeller efficiency; the change of the speed includes all the factors happening at given altitude.
Generally anything more than 600km/h at 10000m seems to be at optimistic side for the standard Bf 109G with DB 605A.
gripen
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Hi Gripen,
>Now your estimate for the FTH sounds to at right ball park ie about 15km/h (2,6%) increase for 100ps (8,4%) output increase (might be still at optimistic side).
Increase compared to what? :-) If you're comparing to the FAF Me 109G-2, remember that my aircraft also has less drag due to the retractable tailwheel.
>But your estimate for 10000m seems to be still quite strange ie about 40km/h (6,9%) increase for about 75ps (9,6%) output increase.
The speed difference is due to a number of different reasons:
1. The FAF Me 109G-2 10 km value is unrealistically slow. See http://www.x-plane.org/users/hohun/me109g-2.jpg
2. The FAF Me 109 is underperforming at 2540 rpm
3. The FAF Me 109 has a fixed tailwheel with higher drag.
4. The FAF Me 109 is running at lower power.
All these effects combined account for the complete speed difference.
>The article serie mentioned above will contain propeller efficiency charts for the Bf 109G (I'm not the author but I have collected some data for him and I have seen a work in progress version of the article).
Sound highly interesting :-) Will the author include English captions for the illustrations (or reproduce the charts with the original German captions)?
>My original approach using simple estimate for rate of the speed change actually counts propeller efficiency; the change of the speed includes all the factors happening at given altitude.
My approach does account for the drop of propeller efficiency with altitude (or rather with tip Mach number). You can see my calculated speed intersects the FAF speed at 10.3 km, so my propeller efficiency at altitude seems fine.
>Generally anything more than 600km/h at 10000m seems to be at optimistic side for the standard Bf 109G with DB 605A.
You're being pessimistic :-)
Regards,
Henning (HoHun)
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Originally posted by F4UDOA
Kweassa,
The P-51D had far worse stall characteristics.
The F4U stall was only bad for a carrier A/C. The P-40 and P-51 were both worse by comparison.
By whos comparison?
A P-51 stalls quite nicely in accelerated, takeoff and departure, clean or configured, an F-4U on the other hand, thats stalled and ends up in spin and under 9,000 feet your dead! Not with a 51. The F-4U shows that you can make anything fly with a lot of power, a barn door with a prop!
In todays airplane do you see GULL WINGs? No I didnt think so, its just a bad plane form design.
Straiga
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Hey everybody,
I been reading a lot of post lately and the amount of info you guys come up with blows my mined, I must work to much or something to have time to research all of this different info, I know you guys arent married, are you?
With all this time we need to teach AH how to make an airplane fly right. I probably going to hear different, but AH flight modeling is wrong. I flown airplanes from 1200 lbs to 550,000 lbs and if I had to work as hard flying planes like in AH in real life, retirement age for commercial pilots would be at 30 years old not at 60.
When Pyro showed me picture of a helicopter, and we were talking about airplane aerodynamics and torque, I then knew the ship was sinking badly.
With all the different airplanes I have flown for a living, the 262 in AH is the closest flying plane to real life, either a prop or jet plane. When you want to roll, loop or what every, just move the controlls and you go with out trimming aileron, rudder, elevator.
Once a plane is trimed to fly at cruise you really dont need to trim anymore. Remember AW! simple.
If your a real pilot like myself you will under stand this, if not you wont know until you been there, sorry.
Dont take this wrong, Im just trying to make the way the planes should fly to improve on your perk points
Fly the 262 in AH, just fly it, thats the closest thing in AH to the real thing, trim for cruise and have fun remember no need to trim anymore. Now isnt that easy. Thats a way a plane should fly!
Hey Pyro, this isnt rocket sience, or boeing,keep it simple, its just a game remember. I could care less about the roll rates of a 109 or P-40, they probably wouldnt be close anyway.
If you some flight experience like myself, lets here from you.
Later
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HoHun,
May I remind you that measured speed of the MT-215 at 10100m CINA was 552km/h which I corrected to about 580km/h at 10000m CINA 2600rpm with altitude correction, rpm correction, output correction and tailwheel. This value is in a very good agreement with other really tested data sets. Also the speed at 10000m is in very good agreement with the Bf 109G-5/AS data given the output, weight and drag difference.
Generally creating a chart does not prove anything if you don't want explain how did you reach such numbers. I have explained quite thoroughly how I have reached my numbers and I have actually sent you real world data I use. Shortly we are back in the beginning; you just want to believe unrealisticly high performance numbers without real world tested proof.
You can contact directly The Suomen Ilmailuhistoriallinen Lehti and Jukka Raunio if you have something to ask about the data he is using:
Suomen Ilmailuhistoriallinen Lehti
Jakomäentie 8b C300
00770 Helsinki
FINLAND
I'm not involved with magazine, I'm just a reader who occasionally helps them to collect data. I pay normal price for the magazine.
gripen
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Hi Straiga,
>If you some flight experience like myself, lets here from you.
John Deakin, "What really counts":
http://www.avweb.com/news/columns/182039-1.html
Let me quote some bits:
"Sure, hours and years aloft can mean something, but other things need to be considered. Take a peek at the embarrassing bio at the end of this column; there are a few things there I'd like to dissect here. I've been getting a good deal of teasing about that from some, and a few have warned me that some may attach more credence to what I say than they should because of my apparent credentials. I hope that's not true, I hope they pay attention because what I say makes sense. If it doesn't make sense, then I want to hear about it."
Regards,
Henning (HoHun)
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Hi Gripen,
>May I remind you that measured speed of the MT-215 at 10100m CINA was 552km/h which I corrected to about 580km/h at 10000m CINA 2600rpm with altitude correction, rpm correction, output correction and tailwheel. This value is in a very good agreement with other really tested data sets.
Well, I don't think the value I calculated (based on your data) of 585 km/h @ 2540 rpm is far off either, considering the difficulties of your previous correction.
Anyway, my point is twofold: The shape of the corrected curve as shown in
http://www.x-plane.org/users/hohun/me109g-2.jpg
is unrealistic. A realistic curve would be convex, with the speed decay accelerating at altitude. This qualitative argument leaves it open whether the aircraft is too fast or too slow, so I imagine you might agree on this one.
The second part of the argument is that my calculations agree with your calculations at 6.4 km and at 10.3 km, while I get a faster speed at the altitiudes in between. That leads me to conclude that your 7 - 9 km speeds are on the low side, though of course you could argue with equal justification that your 10.3 km speed is in fact on the high side.
>Generally creating a chart does not prove anything if you don't want explain how did you reach such numbers.
If you're interested, I'd not only provide the explanation but actually send you my complete spreadsheet :-) It's not user-friendly at all, but I think you have the know-how to find it interesting anyway.
In fact, I'd be thankful for your comments! Either you agree with my calculations, in which case I'd have my point confirmed, or you'd find an error in my calculations, in which case I could improve the accuracy of my spreadsheet. A win-win situation! :-)
>Shortly we are back in the beginning; you just want to believe unrealisticly high performance numbers without real world tested proof.
Gripen, don't pretend you can read my mind. Either you're right, and then you'd not gain anything by telling me because I'd behaving the way you perceive on purpose, or you're wrong, and then you'd do me injustice. Looks like a lose-lose strategy to me :-(
Regards,
Henning (HoHun)
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HoHun,
The measured speed of the MT-215 at 10100m CINA was 552km/h not 574km/h, later number is an error in the chart (I think this has been pointed out at least 3-4 times). Got it? So why your chart contains a wrong value and why your theory is based on the curve created with wrong value?
This has nothing to do with my corrections or my errors, you are simply using the wrong value to support your agenda.
gripen
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Hi Gripen,
>The measured speed of the MT-215 at 10100m CINA was 552km/h not 574km/h, later number is an error in the chart (I think this has been pointed out at least 3-4 times). Got it?
Actually, no :-)
What you wrote before was:
"May I remind you that measured speed of the MT-215 at 10100m CINA was 552km/h which I corrected to about 580km/h at 10000m CINA 2600rpm with altitude correction, rpm correction, output correction and tailwheel."
I understood that you thought 580 km/h was the realistic value for an aircraft with an engine up to the specifications. If I misunderstood you, just point it out and I'll fix it.
>So why your chart contains a wrong value and why your theory is based on the curve created with wrong value?
Note that I suggested: "You could argue with equal justification that your 10.3 km speed is in fact on the high side", which seems to be what you're actually doing :-)
You're charging open doors.
>This has nothing to do with my corrections or my errors, you are simply using the wrong value to support your agenda.
Gripen, please do the paranoia check. Not everyone who disagrees with you is out to get you. It would be very unfortunate if you'd be trapped in the same "agenda/bias" thinking that has struck so many people here, because I really used to appreciate your contributions to this forum.
I guess I won't post in this thread for a while to allow all participants (including myself!) to get a bit of self-critical distance to what was written here. If you'd like to check out my spreadsheet in the meantime, just drop me an email - I still think your comments would be helpful.
Regards,
Henning (HoHun)
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HoHun,
Nonsense, this has nothing to do with my corrections, your chart contains simply a wrong value. If you want to use a corrected value for the curve, you must correct all other data values too.
Regarding your agenda, I don't know what else should I think based on your attitude?
gripen
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Originally posted by Seeker
Thx for trying; but I still don't get it! :-)
Seeker, it's too late now, but tomorrow evening I'll type up a proper explanation for you and I'm sure you will get it. Standby...
Badboy
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Thanks Badz! :-)
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Originally posted by Seeker
Thanks Badz! :-)
I've started a new thread for it...
http://www.hitechcreations.com/forums/showthread.php?threadid=118997
Badboy
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Here is the original FAF speed chart of the MT-215. Note speed at 10000m (10100m CINA): 552km/h
(http://personal.inet.fi/koti/soon.moro/Clipboard.jpg)
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Here is the MT-215 measured speed points marked with blue and the above mentioned error marked with red. Note again speeds above 7000m CINA:
7110m 614km/h
8110m 614km/h
9110m 610km/h
10100m 552km/h
gripen
(http://personal.inet.fi/koti/soon.moro/Clipboard1.jpg)
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Here is the real FAF MT-215 data compared to HoHun's version of the FAF Bf 109G-2 data (2540rpm). Up to the FTH HoHun is quite faithfull to real data set but above that altitude his version of the FAF data starts to live it's own life. And HoHun's theory is based on data set above FTH. Shortly this is called data manipulation.
Note that it's not just speed at 10100m CINA which is falsified but also speeds at 9110m and 8110m. Funny thing is that real values at 9110m and 8110m are quite close to HoHun's calculated version. The real data is actually more concave than his calculated version.
Again it should be noted that all this has absolute nothing to do with my corrections, errors or what so ever. This is strictly HoHun vs FAF data.
(http://personal.inet.fi/koti/soon.moro/HoHunAgenda.jpg)
End of the story, well, actually not quite. Seems that HoHun has actually done some RAM calculations because he noted that the first FTH of the supercharger (better term could be the first rated altitude) with high speed RAM does not agree with calculated RAM effect. Behind this is a very common misunderstanding with DB 605; the operation of the second oil pump of the supercharger is not governed by MAP but altitude. Therefore the engine is allways a bit throttled up to the second FTH. Below is a picture from the DB Spitfire report which clarifies the issue.
gripen
edit: Corrected an error in the chart
(http://personal.inet.fi/koti/soon.moro/Clipboard2.jpg)
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Dear Gripen,
Would you please be so kind to tell our readers which speed values you read off the grey "5.4.43" chart for the following altitudes?
7600 m
8700 m
10300 m
Thanks in advance.
Regards,
Henning (HoHun)
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Ah, noted an error, corrected.
Dear HoHun,
You mean values in line fitted with error value for 10100m CINA? Not relevant for an obivious reason; measured speed at 10100m CINA was 552km/h not 572km/h.
gripen
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Dear Gripen,
>Ah, noted an error, corrected.
Would you now please compare the data points you read off the "4.5.43" chart you posted with the data points in the orange graph in the top speed comparison you posted, and tell us what you found?
Thanks again,
Henning (HoHun)
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HoHun,
I see that none of the real values fit to your version of the FAF data. Clear concavity can be seen above 8000m in the real test data but not in your version. Actually your version does not even match with FAF line with wrong value for 10100m CINA.
Could you now tell us why do you use manipulated data?
Could you now tell us why did you tried to mix 2600rpm corrected data to same graph with 2540rpm data?
gripen
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Hi Gripen,
>I see that none of the real values fit to your version of the FAF data.
That's why I specifically asked you for the data points you read from the 5.4.43 chart at:
7600 m
8700 m
10300 m
These are the data points I used for the orange graph.
So what do you think are the correct speeds for the altitudes I gave, read from the diagram you posted?
Regards,
Henning (HoHun)
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HoHun,
Nonsense, the line is created with wrong value for 10100m CINA. Now you try to pick values from this allready wrong line to support your agenda.
The real values are documented above, try to live with them.
Could tell us why do you use manipulated data?
gripen
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Dearest Gripen,
>Nonsense, the line is created with wrong value for 10100m CINA.
Do you concede that the data points from the "5.4.43" chart at the altitudes I mentioned are portrayed accurately by the orange graph in my chart?
Please don't try to evade a third time.
My question is not whether the original "5.4.43" chart is accurate, but whether my portrayal of the data points I read from it is accurate.
Regards,
Henning (HoHun)
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HoHun,
Well, at the time you presented the graph, you allready knew that the real value for the 10100m CINA was 552km/h (it had been pointed out several times). So you certainly knew that the graph was wrong before you posted it.
Basicly it does not matter what values can be found from these altitudes, you knew these were wrong before you used them.
Therefore you certainly knew that the data you use is manipulated.
Now if you just tell us why did you do it despite you knew that values are wrong?
gripen
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Hi Gripen,
Sadly, you tried to evade a fourth time, so let me repeat my question:
"Do you concede that the data points from the "5.4.43" chart at the altitudes I mentioned are portrayed accurately by the orange graph in my chart?"
Would you please answer, if possible with a simple "yes" or "no", and no poison darts this time?
Thank you in advance,
Henning (HoHun)
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HoHun,
Basicly you are hiding behind an error in the FAF chart. And you knew that error before you posted the graph.
So why did you do it?
gripen
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Hi Gripen,
It's very sad that you seem to be unable to admit that my usage of the "4.5.43" graph was accurate with the simple and clear "yes" I deserve.
>Basicly you are hiding behind an error in the FAF chart. And you knew that error before you posted the graph.
Actually, you had provided no documentation about the error, so it was only a claimed error so far. I'm quite ready to trust you (as I have done several times in this thread), but in that special point, several contradicting figures were floating about, including your own statement from your 06-03-2004 10:24 AM post:
"May I remind you that measured speed of the MT-215 at 10100m CINA was 552km/h which I corrected to about 580km/h at 10000m CINA 2600rpm with altitude correction, rpm correction, output correction and tailwheel. This value is in a very good agreement with other really tested data sets."
Note that you suggested 580 km/h @ 10.1 km, while the "5.4.32" graph I quoted only lists 572 km/h @ 10.3 km.
Besides, along with posting the chart, which only was meant to illustrate that it was possible to calculate a fairly good estimate from a single data point if you have an engine power chart (so my prediction was not affected by the 10.3 km data point anyway), I pointed out in my post from 06-01-2004 07:57 PM:
"Above full throttle height, my graph actually looks more realistic than the FAF test data because the latter features a linear shape where it should realistically be slightly convex, like my calculated shape."
I added in my post from 06-03-2004 07:16 PM:
"The shape of the corrected curve as shown in
http://www.x-plane.org/users/hohun/me109g-2.jpg
is unrealistic. A realistic curve would be convex, with the speed decay accelerating at altitude. This qualitative argument leaves it open whether the aircraft is too fast or too slow, so I imagine you might agree on this one."
Obviously, a lower speed at 10.3 km as you suggest helps with that requirement, so your suggestion that I was trying to "manipulate data" completely lacks any justification.
In fact, I was repeatedly pointing out doubts about the realism of exactly that part of the curve you're now trying to bash me for.
I hope you realize now that your accusations are based on nothing but a misunderstanding on your part, and take the necessary consequences. I'd really prefer to continue this discussion on friendly terms with you :-)
Regards,
Henning (HoHun)
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HoHun,
Well, now your attitude is much more constructive than earlier. Generally I have provided you quite lot of documentation during this discussion or do you have something to complain? But it seems that you are more willing to believe things which favor Bf 109G than things which do not. From my viewpoint the problem is that you have not told how did you reach your numbers; I'm not interested to spend hours checking not so clear spreadsheets, a short explanation will do fine. I can see you have calculated RAM just like I did for the output but rest of the calculation is unclear.
My about 580km/h (actually 578km/h at 10000m) estimate is for 2600rpm and tail wheel in ie around 568km/h tailwheel down (details in my post 24.5 12:11AM, basicly all are linear quick and dirty estimates with output estimates but no drag nor prop efficiency calculations). Note that all other data points should be corrected too for the curve.
Regarding your chart , manipulation etc. The attitude you have presented earlier in this thread leaves very little room for neutrality; I don't know how many messages it took to point out that 7000m FTH is pretty much wishfull thinking, the validity of the Russian data set, Kennblatt which actually says 6,4km etc... I still see using that chart quite unvalid because it gives a wrong picture about FAF data set; above FTH it's not correct and between 1st and 2nd FTH it's not correct for the technical reason described above (I think both points are quite well documented above).
gripen
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Added points to jpg for HoHun's request. Did not fit well.
gripen
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Hey HoHun are you flying in AH ?
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Hi Gripen,
>Added points to jpg for HoHun's request. Did not fit well.
Try to get the figures from a clearer copy:
http://www.x-plane.org/users/hohun/MT215_speed.jpg
Regards,
Henning (HoHun)
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Hi 13Promet,
>Hey HoHun are you flying in AH ?
I gave Aces High a try, and though I thought it to be a great simulation with a lot of good features, I didn't really enjoy the gameplay aspects :-/ Too much like the ancient Air Warrior (which was quite good actually - it just grew old on me after a couple of years).
Regards,
Henning (HoHun)
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HoHun,
I quess this is a human error from your side? Anyway, basicly this means that your chart shows 6km/h too fast speed at 10300m and it also misses the concavity of the FAF curve (which itself contains an error). Basicly you give lot of reasons to be paranoid...
gripen
(http://personal.inet.fi/koti/soon.moro/MT215clip.jpg)
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Originally posted by HoHun
Hi 13Promet,
>Hey HoHun are you flying in AH ?
I gave Aces High a try, and though I thought it to be a great simulation with a lot of good features, I didn't really enjoy the gameplay aspects :-/ Too much like the ancient Air Warrior (which was quite good actually - it just grew old on me after a couple of years).
Regards,
Henning (HoHun)
Looks like AHII gameplay is going to be very similar to WB FH.
Let's wait and see.
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HoHun would hate it the fuel consumption has been reworked and the fuel multiplier is at 2.
RTB every 30min........
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Batz,
Well, total error of the HoHun's calculated version of the FAF data including his error (or agenda, I can't say because I'm supposed to be a paranoid) and FAF's error is around 45km/h at 10300m CINA (real data gives about 540km/h assuming linear estimate), that does just 8,5% increase. So I believe the 8,5% increase in the fuel consumption would be in right ball park instead 100% ;)
gripen
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Hi Gripen,
>I quess this is a human error from your side?
"Human error" is worlds apart from "falsifying" or "data manipulation". I'd say it's time for an apology now.
Note that in your first attempts to add the FAF data to my chart, you got two of the data points wrong by 10 km/h, so you can hardly complain if I'm off by 6 km/h.
Compared to the average "4.5.43" graph, the FAF data points show differences of -14 km/h @ 7110 m and +15 km/h @ 9110 m anyway - just to add a little perspective.
If you're interested, my offer to send you the complete spreadsheet I used for my calculation still stands. I'd be quite happy to have it checked thoroughly by an independend thinker :-)
Regards,
Henning (HoHun)
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HoHun,
Please calm down now. After all it was your own error which caused all this.
You can send the sheet to me and I'll see if I can understand it but don't expect too much. As you might have noticed, I avoid calculations (expect for checking valitdity of the data) and prefer documented stuff. This thread is a good example what a small and simple error can cause to a calculation.
gripen
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Hi Gripen,
>Please calm down now. After all it was your own error which caused all this.
My error caused a 6 km/h difference.
You accused me me of "falsification" and "data manipulation" - two very serious but completely unfounded accusations, totally out of proportion for a rather minor inaccuracy.
From a decent guy, I'd expect a public apology for such a public accusation, without any attempts to wiggle his way out of it. I'd be quite ready to forget about "all this" afterwards.
Regards,
Henning (HoHun)
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HoHun,
Nonsense. Your total error at 10100m CINA in the case of the accidentally manipulated (or falsified) FAF curve is about 4km/h if compared to allready false value and about 24km/h if compared to real value which you apparently did not want to believe despite I had directly quoted FAF report before.
In the case of the calculated curve, the errors are about 9 and 29km/h respectively. In addition the values between 1st and 2nd FTH are wrong because you did not know how the variable speed system is adjusted.
The situation is very simple. You did the manipulated the curve, the evidence is above. It does not matter if you did it accidentally or purposedly.
gripen
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Hi Gripen,
>The situation is very simple. You did the manipulated the curve, the evidence is above. It does not matter if you did it accidentally or purposedly.
Sure, an accidental 6 km/h error in reading a figure off a chart is the same as purposefully falsifying data ... <- Irony, as I have to point out in case you're actually as naive as you pretend to be.
You're on my ignore list now because your lame excuse insults my intelligence.
Kind regards,
Henning (HoHun)
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HoHun,
Actually your error is two fold; 200m altitude increase for given speed which is allready 20km/h too fast due to error in the FAF chart. Overall your chart has pretty much nothing to do with reality above FTH. In addition you are unable to see anything wrong in your actions despite all this is caused by your own errors and unability accept data which does not support your agenda.
Thanks for putting me to ignore list.
gripen
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Gripen, there is only one valid phrase to describe your one-man crusade here : pathetic. It`s so typical from you, anybody who reads through your post can only find only one source for the Gripen`s postings : other postings from the same Gripen, his misconceptions, wannabe versions only 'supported' by his other misconceptions and wannabe versions. Your bias vs. the 109 series is plain obvious from your post history, you show a pattern of dismissing any source that would disagree with your conceptions.
Accusing HoHun with bias, manipulation and other BS is just plain miserable on your part.
HoHun, and I this perception of mine would be widely agreed by those who ever seen his post, is one with the most balanced and open minded member of aviation forums. Few could match him in this respect. You will never be able to. He was right in putting you on an Ignore List; I will do the same, as there`s nothing to learn from you, even though you may have many good sources, but it all becomes useless when it`s represented through a zealot blinded by his own self-righteousness and I-cant-be-wrong attitude. Certainly it`s a waste of time to deal with you at all.
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Dear Isegrim,
The evidence is above: I posted sources, showed data as it is and pointed out errors.
Other side choosed to create calculation model which uses apparently two parameters: FTH and speed at the highest altitude. In this case charted speed at 10100m is relatively highest (due to error in the chart) so the results for other altitudes above FTH will therefore be higher than in real life.
Even without manipulated data the results of this kind of model are obiviously biased because performance above FTH depends on just two values. The better aproach would be to fit curve by using least squares method which balances errors (there are other methods too).
Note that other side have not corrected his errors nor errors in the data set despite these have been pointed out with documentation. The reason is obivious; if the errors are corrected others side's theory on speed of the Bf 109G is gone. And this is probably the real reason the other side choosed to leave discussion.
Thanks for putting me to your ignore list.
gripen
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Hi Isegrim,
Thanks for your support! :-)
Nice to hear you appreciate my posts in spite of our occasional disagreements - a bit of constructive tension is a good thing in my opinion :-)
(I'd also like the thank the people who sent me supportive e-mails. To answer your questions - no, I don't think I'm wasting my time here, and yes, I'll provide further details on my point of view :-)
Regards,
Henning (HoHun)
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Shame.
Two of the guys who's writings here I respect the most getting their knickers in a twist....
Gentlemen; release your sphincters.
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Hi everyone,
Due to your requests, I'm going to try and explain a bit about scientific standard procedures, as this is really useful stuff if you're dealing with aircraft tests, and how they apply to the Me 109G-2 discussion.
First of all, if we're talking about "errors", science usually discerns between "random" errors and "systematical" errors.
"Random" errors are due to inaccuracies both in the experiment itself as well as introduced by the observing instruments. Random errors mean that each repetition of the experiment will yield a different set of results which - depending on the accuracy of testing procedure and equipment - will be more or less similar to those from other repetitions of the same experiment. To keep the inaccuracies introduced by random error down to a minimum, experiments often have to be repeated multiple times to yield an average result that can be used with some sort of confidence. (There are mathematical concepts for this kind of confidence :-)
"Systematic" errors are errors that would be predictable and correctable if you figured out their reasons. The problem is, you never know if you have figured out all of the errors in your experiment. Unlike random errors, systematic errors don't yield varying results with repetitions of the experiment with "everything else being equal", but rather give the results an identical bias to one side or the other.
Let's have a look at the FAF Me 109G-2 data now:
http://www.x-plane.org/users/hohun/me109g-2b.jpg
First, concentrate on the yellow graph. That's the data from Gripen's table, with the 10 km value taken from Gripen's narrative on his request. Below full throttle height, everything looks well, but from full throttle height up, you see a rather kinked graph.
Are the kinks due to systematic errors? Probably not. To begin with, the table provided by Gripen seems to be accounting for some systematical errors, like the compressibility error of the airspeed indicator, the error of the engine tachometer, the difference between standard and real atmosphere etc.
More importantly, if the kinks in the graph were due to systematic errors, the test aircraft's engine would have to be considered seriously screwed up because it loses power dramatically above full throttle height, then sustains and even increases power beyond that of a properly performing engine up to 9 km before dropping dramatically again. Such an aircraft obviously would be unsuitable for testing, and if tested, completely non-representative for the tested type.
While it's impossible to exclude that the FAF flight tests could have suffered from unrecognized systematical errors, the kinks in the curve you're seeing are probably due to random errors only. Remember that you reduce the impact of random errors by repeating an experiment multiple times. From the caption of the table Gripen provided, it seems that the Me 109G-2 data in that table was collected in just 50 min, which probably means that every data point was measured only once. That leaves the results wide open for random errors.
(It's no suprise that the random errors are recognizable so clearly above full throttle height since specific excess power is so poor that it takes a long time to accelerate to top speed, and minor disturbances of the experiment have the greatest effect up there.)
Now have a look at the red and blue graphs now that are labelled "lower/upper error boundary". They define a +/- 15 km/h envelope around the "5.4.43" data and include all FAF test data (except the 10 km value Gripen requested a downgrade for). The actual speed of the FAF Me 109G-2 probably (but not definitely) should be expected to be within the envelope defined by the red and the blue graph.
As you can see, my speed prediction is safely within these bounds. It's close to the upper boundary, but doesn't exceed them, so that the FAF data points do not contradict my prediction.
Considering the random error inherent in the FAF test, it's completely pointless to try and argue against my prediction based on a single data point because the accuracy for the FAF test simply doesn't allow it. All in all, the FAF data just provides five measurements of performance from full throttle height up, which is slightly better than a single data point but still insufficient to call any prediction within (or somewhat beyond) these bounds impossible, or even just improbable.
Judging by the FAF data, my prediction may not be the most probable one (which should be supposed to be the average graph the FAF provided, of course), but it's definitely not an unlikely one either.
The exact math would be rather complicated, but you might find it interesting that in the age of slide-rules, the performance graph often resulted from bending a rubber-encased lead rod into the approximate shape of a typical performance curve, and after using Eyeball Mk I to decide whether the optimum fit had been achieved, fusing the lead rod as a ruler to draw the curve :-)
With data sets like the one provided by Gripen, you wouldn't get much closer to the truth with complex math, anyway.
So I hope I've now managed to explain why I couldn't be any less impressed by the failure of my prediction to match the FAF data above full throttle height :-)
Only one data point from the FAF data has actually provided information to be used by my prediction, and that's top speed at full throttle height. The rest is based on a decent physics model and a DB605A power chart. Both might contain errors resulting in an unrealistic estimate, but comparison to this particular set of FAF data will not help to find out if that's the case. And the physics model definitely is unbiased - it was developed for analysis of the P-40 :-)
Regards,
Henning (HoHun)
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Whats a physics model?
HiTech
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When I saw the origonal plots I wondered about the standard errors of these estimates. I think its under appreciated how noisy these numbers can be when only 1 or 2 tests are run under any set of parameters.
U.S. engine makers always distributed power curves with a disclaimer of 5%...
-Blogs
Originally posted by HoHun
Hi everyone,
Due to your requests, I'm going to try and explain a bit about scientific standard procedures, as this is really useful stuff if you're dealing with aircraft tests, and how they apply to the Me 109G-2 discussion.
First of all, if we're talking about "errors", science usually discerns between "random" errors and "systematical" errors.
"Random" errors are due to inaccuracies both in the experiment itself as well as introduced by the observing instruments. Random errors mean that each repetition of the experiment will yield a different set of results which - depending on the accuracy of testing procedure and equipment - will be more or less similar to those from other repetitions of the same experiment. To keep the inaccuracies introduced by random error down to a minimum, experiments often have to be repeated multiple times to yield an average result that can be used with some sort of confidence. (There are mathematical concepts for this kind of confidence :-)
"Systematic" errors are errors that would be predictable and correctable if you figured out their reasons. The problem is, you never know if you have figured out all of the errors in your experiment. Unlike random errors, systematic errors don't yield varying results with repetitions of the experiment with "everything else being equal", but rather give the results an identical bias to one side or the other.
Let's have a look at the FAF Me 109G-2 data now:
http://www.x-plane.org/users/hohun/me109g-2b.jpg
First, concentrate on the yellow graph. That's the data from Gripen's table, with the 10 km value taken from Gripen's narrative on his request. Below full throttle height, everything looks well, but from full throttle height up, you see a rather kinked graph.
Are the kinks due to systematic errors? Probably not. To begin with, the table provided by Gripen seems to be accounting for some systematical errors, like the compressibility error of the airspeed indicator, the error of the engine tachometer, the difference between standard and real atmosphere etc.
More importantly, if the kinks in the graph were due to systematic errors, the test aircraft's engine would have to be considered seriously screwed up because it loses power dramatically above full throttle height, then sustains and even increases power beyond that of a properly performing engine up to 9 km before dropping dramatically again. Such an aircraft obviously would be unsuitable for testing, and if tested, completely non-representative for the tested type.
While it's impossible to exclude that the FAF flight tests could have suffered from unrecognized systematical errors, the kinks in the curve you're seeing are probably due to random errors only. Remember that you reduce the impact of random errors by repeating an experiment multiple times. From the caption of the table Gripen provided, it seems that the Me 109G-2 data in that table was collected in just 50 min, which probably means that every data point was measured only once. That leaves the results wide open for random errors.
(It's no suprise that the random errors are recognizable so clearly above full throttle height since specific excess power is so poor that it takes a long time to accelerate to top speed, and minor disturbances of the experiment have the greatest effect up there.)
Now have a look at the red and blue graphs now that are labelled "lower/upper error boundary". They define a +/- 15 km/h envelope around the "5.4.43" data and include all FAF test data (except the 10 km value Gripen requested a downgrade for). The actual speed of the FAF Me 109G-2 probably (but not definitely) should be expected to be within the envelope defined by the red and the blue graph.
As you can see, my speed prediction is safely within these bounds. It's close to the upper boundary, but doesn't exceed them, so that the FAF data points do not contradict my prediction.
Considering the random error inherent in the FAF test, it's completely pointless to try and argue against my prediction based on a single data point because the accuracy for the FAF test simply doesn't allow it. All in all, the FAF data just provides five measurements of performance from full throttle height up, which is slightly better than a single data point but still insufficient to call any prediction within (or somewhat beyond) these bounds impossible, or even just improbable.
Judging by the FAF data, my prediction may not be the most probable one (which should be supposed to be the average graph the FAF provided, of course), but it's definitely not an unlikely one either.
The exact math would be rather complicated, but you might find it interesting that in the age of slide-rules, the performance graph often resulted from bending a rubber-encased lead rod into the approximate shape of a typical performance curve, and after using Eyeball Mk I to decide whether the optimum fit had been achieved, fusing the lead rod as a ruler to draw the curve :-)
With data sets like the one provided by Gripen, you wouldn't get much closer to the truth with complex math, anyway.
So I hope I've now managed to explain why I couldn't be any less impressed by the failure of my prediction to match the FAF data above full throttle height :-)
Only one data point from the FAF data has actually provided information to be used by my prediction, and that's top speed at full throttle height. The rest is based on a decent physics model and a DB605A power chart. Both might contain errors resulting in an unrealistic estimate, but comparison to this particular set of FAF data will not help to find out if that's the case. And the physics model definitely is unbiased - it was developed for analysis of the P-40 :-)
Regards,
Henning (HoHun)
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Hi Hitech,
>Whats a physics model?
Oh, that's just another word for my spreadsheet :-)
http://en.wikipedia.org/wiki/Model_(abstract)
"By abstract model (or conceptual model) we mean a theoretical construct that represents social or physical processes by a set of variables and a set of logical and quantitative relationships between them."
I could also call it an aircraft model but that would probably be misunderstood :-)
Regards,
Henning (HoHun)
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Well, this is going to strangest discussion for me so far; HoHun has ignored me but just after I have pointed out that his calculation is biased right from the beginning, he suddenly jumps in and gives another (longish) explanation for his actions.
We have no other starting point for the error analysis than the original and unaltered FAF data set as seen here again:
(http://personal.inet.fi/koti/soon.moro/Clipboard.jpg)
This set comes from the very same report as the chart, but this set does not contain that error which HoHun continously uses to support his agenda. The chart is made using this data set.
If we assume that these measurements have +/- 15 km/h error as HoHun suggests then we have following values for error boundaries:
(http://personal.inet.fi/koti/soon.moro/bound.jpg)
If we ad them to HoHun's new version of the reality, then we have a following chart:
(http://personal.inet.fi/koti/soon.moro/HoHunAgenda2.jpg)
Now we can see that if we use real measured data and assume +/- 15 km/h error then the fastest speed the MT-215 could reach at 10100 m CINA was below errorneous 572 km/h value in the chart and actually HoHun's own version admits this.
Then we should analyze a bit HoHun's error boundary theory. For one reason or another he has choosen to use allredy altered set (manipulated during curve fitting) for his purposes ie he uses errornenous curve from the FAF chart, this is a big error because most of the measured points are lost and also real error boundary is lost from these altitudes. Therefore the error boundary is correct just at two altitudes 6420 and 8110 m CINA. It very obivious that HoHun does not understand the term error boundary or he has purposedly created errorneous chart. As an example we can look the error boundary at 9110 m CINA, real error range is 595-625 km/h but the chart gives about 580-610 km/h
But actually error boundaries have quite little to do with built in bias in the HoHun's original chart seen here:
(http://personal.inet.fi/koti/soon.moro/me109g-2.jpg)
Here HoHun uses the errorneous FAF curve as base for his analyze and actually managed to manipulate it during process. But lets assume for a moment that it's a "real" curve. For one reason or another he has chosen use the speed at highest altitude (572km/h at 10300m) for calculate new curve. Now it should be asked is there any particular reason to choose speed at highest measured altitude for calculation? If the calculation is correct then it should give very similar values despite what ever speed and altitude combination is choosed as a base for calculation. But if we look the new calculated speed curve, we can see that the only point where it crosses "real" curve is that highest altitude. Therefore it is easy to understand that by choosing any other speed and altitude combination would result worse results and therefore the method is biased right from the beginning.
Generally further HoHun goes in his explanations, deeper he sinks.
gripen
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Originally posted by HoHun
Hi Hitech,
>Whats a physics model?
Oh, that's just another word for my spreadsheet :-)
http://en.wikipedia.org/wiki/Model_(abstract)
"By abstract model (or conceptual model) we mean a theoretical construct that represents social or physical processes by a set of variables and a set of logical and quantitative relationships between them."
I could also call it an aircraft model but that would probably be misunderstood :-)
Regards,
Henning (HoHun)
Golly G Wizz I hope I can learn to model with spread sheets some day. Will you pretty please teach me how to do this stuff HoHun.
Hummor off.
Nice evaluation HoHun.
HiTech
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If I follow the argument, everyone of these plots lies in the assumed standard error of the estimates. In that case there's no way to say that one is right or wrong.
If I understand what HoHun has done, he's fit a curve based on the effect of changes in atmospheric pressure on engine horsepower, possibly taking into effect changes in drag as well.
One way to check the robustness of his model is simply to generate several curves using a different point of the actual test data and examining the degree to which these curves vary (i.e. sensitivity analysis).
What is almost certainly is true is that the relationships are non-linear, which means the errors get bigger the further away the estimated relationship is plotted from the actual data.
-blogs
Originally posted by gripen
Well, this is going to strangest discussion for me so far; HoHun has ignored me but just after I have pointed out that his calculation is biased right from the beginning, he suddenly jumps in and gives another (longish) explanation for his actions.
We have no other starting point for the error analysis than the original and unaltered FAF data set as seen here again:
This set comes from the very same report as the chart, but this set does not contain that error which HoHun continously uses to support his agenda. The chart is made using this data set.
If we assume that these measurements have +/- 15 km/h error as HoHun suggests then we have following values for error boundaries:
If we ad them to HoHun's new version of the reality, then we have a following chart:
Now we can see that if we use real measured data and assume +/- 15 km/h error then the fastest speed the MT-215 could reach at 10100 m CINA was below errorneous 572 km/h value in the chart and actually HoHun's own version admits this.
Then we should analyze a bit HoHun's error boundary theory. For one reason or another he has choosen to use allredy altered set (manipulated during curve fitting) for his purposes ie he uses errornenous curve from the FAF chart, this is a big error because most of the measured points are lost and also real error boundary is lost from these altitudes. Therefore the error boundary is correct just at two altitudes 6420 and 8110 m CINA. It very obivious that HoHun does not understand the term error boundary or he has purposedly created errorneous chart. As an example we can look the error boundary at 9110 m CINA, real error range is 595-625 km/h but the chart gives about 580-610 km/h
But actually error boundaries have quite little to do with built in bias in the HoHun's original chart seen here:
Here HoHun uses the errorneous FAF curve as base for his analyze and actually managed to manipulate it during process. But lets assume for a moment that it's a "real" curve. For one reason or another he has chosen use the speed at highest altitude (572km/h at 10300m) for calculate new curve. Now it should be asked is there any particular reason to choose speed at highest measured altitude for calculation? If the calculation is correct then it should give very similar values despite what ever speed and altitude combination is choosed as a base for calculation. But if we look the new calculated speed curve, we can see that the only point where it crosses "real" curve is that highest altitude. Therefore it is easy to understand that by choosing any other speed and altitude combination would result worse results and therefore the method is biased right from the beginning.
Generally further HoHun goes in his explanations, deeper he sinks.
gripen
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Hi Blogs,
>When I saw the origonal plots I wondered about the standard errors of these estimates.
>I think its under appreciated how noisy these numbers can be when only 1 or 2 tests are run under any set of parameters.
Roger on the noise :-)
Since the 5 data points from full throttle height up are not repetitions of the same experiments, I couldn't really determine the standard deviation. (OK, it's infinite, but that's no help :-)
If (remembering that it actually isn't correct!) you consider them repetitions of the same experiment and for example figure just the difference to the "5.4.43" graph, the standard deviation is 13.3 km/h. If you discount the 10 km value, it's still 11.4 km/h.
Of course, that wouldn't be the proper way to do a real experiment. The proper way is formulating a hypothesis on the relation of altitude and speed, determining the pivotal constants (like drag coefficients), and then using the experiment to find out the value of these constants along with their standard deviation.
A speed curve determined in accordance with scientific procedures wouldn't just be a curve fitted between a set of measured points, but actually a completely fictional curve entirely based on a calculation using the constants derived from the tests. This curve has an homogenous error as all points of it are based on the same constant (complete with its error).
It's a common misunderstanding that measured data is superior to calculated data. The FAF example shows that measured data can be subject to a considerable random error.
Fortunately, the low-altitude data is good enough to determine the drag coefficients, so it's possible to calculate the high-altitude performance from these values, ignoring the high-altitude measurements completely :-)
>U.S. engine makers always distributed power curves with a disclaimer of 5%...
No "I want my money back" that way ;-)
NACA actually pointed out that often, speed tests are based on the assumption that the engine performs up to specifications without actually checking whether that's actually correct, so that comparisons between different test aircraft of the same type with the same engine model could lead to wrong conclusions about the effects of aerodynamic changes.
(That's another reason why calculated data, based on a standard power graph, can beat measured data - which typically shows speeds achieved on an unknown power output.)
Regards,
Henning (HoHun)
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HoHun
I lurk here a lot, and a search of threads in which Gripen has posted reveals two things...
Firstly, he must have the last word, even if it is wrong.
Secondly, he has difficulty understanding the reports he reads, because he lacks the analytical skills to interpret them correctly, and then attempts to win any subsequent debate by repeating his misconceptions to the point of nausea.
You offered to show him your calculations, the open actions of an honest debater who wishes to encourage transparency. Gripen refused to look at them, the defensive reaction of someone who is either afraid of exposing his inability to comprehend the physics/math involved, or is afraid that such clarity will expose his own agenda.
That is his modus operandi, you won't be the first to withdraw from debate with Gripen, due to the utter futility of reasoning to penetrate his chosen dogma, and you probably won't be the last.
Dweeb
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Originally posted by hitech
Whats a physics model?
HiTech
That thing you wrote ten years ago to make confirmed kill wurk rite... Ya big tease :)
Dweeb
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Hi Dweeb!
>That thing you wrote ten years ago to make confirmed kill wurk rite... Ya big tease :)
LOL! I've got to admit I'm still suffering from the after-effects of oxygen starvation - after years of holding my breath for the Do 335 promised in that CGW issue :-)
>I lurk here a lot [...]
Hey, are you a FSFORUM survivor, too? CK experience and CIS terminology would fit :-)
Regards,
Henning (HoHun)
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Hi Hitech,
>Golly G Wizz I hope I can learn to model with spread sheets some day. Will you pretty please teach me how to do this stuff HoHun.
You probably wouldn't learn much - it's like a one-dimensional flight simulation incapable of real-time operation, and I think you're already one or two steps ahead of that with your own project ;-)
>Nice evaluation HoHun.
Thanks! :-)
Regards,
Henning (HoHun)
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Hi Blogs,
>One way to check the robustness of his model is simply to generate several curves using a different point of the actual test data and examining the degree to which these curves vary (i.e. sensitivity analysis).
Since I calculate the drag from the reference point, that's indeed a working option.
You can see the results from my graph:
The data points from sea level to 2.4 km would lead to the same results as the 6.4 km data point I actually used. (My calculated speed graph coincedes with the measured speed there.)
Between 2.4 km and 6.4 km, we see a systematic difference in the engine power graph. I'd have to predict a differing speed curve from these points, but that would be misleading because obviously, in this altitude band the FAF aircraft's engine was performing differently from the DB605A chart I used for my prediction. Accordingly, it's not indicative of a problem with the physics model.
Above 6.4 km, we've got 4 data points with obvious random variations, and only the use of one of them would yield the curve I predicted.
Using the others would result in considerably slower curves - and that includes speed at full throttle height.
Regards,
Henning (HoHun)
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Well, I have pointed out ealier why the engine output can't be calculated using full RAM below FTH as seen here:
(http://personal.inet.fi/koti/soon.moro/Clipboard2.jpg)
The engine is throttled up to FTH despite variable speed system because it is adjusted by altitude, see the curve called gebläsedruck in the graph (pressure between impeller and throttle valve). The engine output below FTH is a bit lower at high speed than at climb speed because it's throttled more below FTH due to RAM. If the full RAM is assumed then gebläsedruck would have been same as ladedruck (MAP) resulting higher output. Yes, there is a systematic error but not in the FAF graph.
gripen
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Originally posted by HoHun
Above 6.4 km, we've got 4 data points with obvious random variations, and only the use of one of them would yield the curve I predicted.
Using the others would result in considerably slower curves - and that includes speed at full throttle height.
Well, that is what I have been saying all the time. HoHun has been using the point which gives him best results. And that point itself is 20km/h off due to error in the FAF chart.
Regarding the errors in the FAF measurements, the errors are true only for measured points, not for the fitted curve. The fitted curve in the FAF chart is errorneous due to the reason pointed out several times above and therefore it can't be used as data for the analysis.
gripen
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Anyone who has taken a chemistry class can appreciate the puzzle of knowing what result you are supposed to get and yet not getting it. Sometimes it's bad procedure, but often it results from using instruments too crude for the task...
Anyone who reads my posts knows I am preoccupied with engines (a detroit boy to the end). The data I like to use most comes from the engine makers and is independent of the installation. Such data comes from the most controlled experiments one can get with a motor meant for a plane.
The cost of this precision however, is that the numbers won't match up with flight test data...
-Blogs
Originally posted by HoHun
Hi Blogs,
>When I saw the origonal plots I wondered about the standard errors of these estimates.
>I think its under appreciated how noisy these numbers can be when only 1 or 2 tests are run under any set of parameters.
Roger on the noise :-)
Since the 5 data points from full throttle height up are not repetitions of the same experiments, I couldn't really determine the standard deviation. (OK, it's infinite, but that's no help :-)
If (remembering that it actually isn't correct!) you consider them repetitions of the same experiment and for example figure just the difference to the "5.4.43" graph, the standard deviation is 13.3 km/h. If you discount the 10 km value, it's still 11.4 km/h.
Of course, that wouldn't be the proper way to do a real experiment. The proper way is formulating a hypothesis on the relation of altitude and speed, determining the pivotal constants (like drag coefficients), and then using the experiment to find out the value of these constants along with their standard deviation.
A speed curve determined in accordance with scientific procedures wouldn't just be a curve fitted between a set of measured points, but actually a completely fictional curve entirely based on a calculation using the constants derived from the tests. This curve has an homogenous error as all points of it are based on the same constant (complete with its error).
It's a common misunderstanding that measured data is superior to calculated data. The FAF example shows that measured data can be subject to a considerable random error.
Fortunately, the low-altitude data is good enough to determine the drag coefficients, so it's possible to calculate the high-altitude performance from these values, ignoring the high-altitude measurements completely :-)
>U.S. engine makers always distributed power curves with a disclaimer of 5%...
No "I want my money back" that way ;-)
NACA actually pointed out that often, speed tests are based on the assumption that the engine performs up to specifications without actually checking whether that's actually correct, so that comparisons between different test aircraft of the same type with the same engine model could lead to wrong conclusions about the effects of aerodynamic changes.
(That's another reason why calculated data, based on a standard power graph, can beat measured data - which typically shows speeds achieved on an unknown power output.)
Regards,
Henning (HoHun)
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Grippen
Can you explain this chart for me? Is the top curve intake pressure (before hitting the carburetor) and the bottom the rated pressure of the engine? What are the two straight lines in the curve below?
-Blogs
Originally posted by gripen
Well, I have pointed out ealier why the engine output can't be calculated using full RAM below FTH as seen here:
(http://personal.inet.fi/koti/soon.moro/Clipboard2.jpg)
The engine is throttled up to FTH despite variable speed system because it is adjusted by altitude, see the curve called gebläsedruck in the graph (pressure between impeller and throttle valve). The engine output below FTH is a bit lower at high speed than at climb speed because it's throttled more below FTH due to RAM. If the full RAM is assumed then gebläsedruck would have been same as ladedruck (MAP) resulting higher output. Yes, there is a systematic error but not in the FAF graph.
gripen
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blogs,
Here is the entire page:
(http://personal.inet.fi/koti/soon.moro/DBSpit1.jpg)
Upper part of the page is naturally speed data. Stau means RAM. Gebläsedruck is pressure between impeller and throttle and ladedruck is MAP. Bottom part is air temperature, measured and CINA.
As you probably know that the DB 605 had variable speed supercharger with hydraulic coupling. The hydraulic coupling had two pumps of which one worked all the time making supercharger to work at fixed speed up to 2km. The second oil pump was governed by barometric valve which started to work at around 2km the to increase speed of the supercharger then it gradually increased the speed of the supercharger up to about 5km and above that altitude supercharger worked as a fixed speed system again.
A common missunderstanding is that the supercharger of the DB 605 worked at optimal speed below FTH (between 1st and 2nd FTH). But as you can see from the graph, the engine was throttled all the way up to FTH; gebläsedruck is higher than ladedruck. Therefore it's easy to understand that with high speed RAM the engine is more throttled than at climb speed RAM and therefore the engine works more efficiently at climb speed up to the FTH. If the supercharger had worked at optimal speed between 1st and 2nd FTH, then ladedruck and gebläsedruck would have been same at that range.
If I understand correctly, HoHun has calculated his version assuming full RAM and engine working at full throttle between 1st and 2nd FTH ie at maximal efficiency. Therefore his calculation gives higher speed between 2,4 and 6,4km than FAF data. But this is not the way the DB 605 worked; output curve is given with about climb speed RAM so assuming full RAM for high speed will result overestimated output. HoHun has apparently a systematical error in his calculations between 2,4 and 6,4km.
Regarding statistics and FAF data. There is no sense to speak about standard deviation with such a small data set:
(http://personal.inet.fi/koti/soon.moro/Clipboard1.jpg)
As you can there is lot of variation so it pretty much impossible to calculate anything meaninfull. But one thing should be noted; all HoHun's analyses are based on errorneous curve with wrong speed value at 10100m CINA, he continously refuses to use real measured value for that altitude. It should also noted that if his model gives about right FTH only with that errorneous value for 10100m, then there appears to be another systmatical error in his calculation (which one could call bias).
gripen
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I get the first graph - incidentally does that include a plot of a Spit V with a DB605 installed? Now that could be used for making some aerodynamic comparisons...
The second plot is ram air. Now there are a lot of ways to measure this. On a specific plane it is typically, but not always done done assuming level flight. In any case the thing to work out is the maximum contricution of RAM air to engine horsepower from the chart.
The third plot makes sense too, although it's not clear to me that the pilot would have the throttle wide open for most of the range under 6.7 km. I know some planes (FW 190?) had all these things integrated in the pilot's controls, but I don't know about the 109. And I like your description of the supercharger. Didn't know those things.
The first and third charts seem to imply a supercharger tax on the engine between 2 and 4 km. More horsepower is consumed, but I suspect the pilot has to throttle back a bit until after 4 km.
But I am just guessing here. A simple translation of a G-10 or k manual should tell us.
Is the last chart measured air temperature, a plot against a standard atmosphere, or both?
So your argument is that HoHun is projecting a speed value after setting aside a range of altitudes where the pilot is forced to throttle back the engine? In this case it really does matter what speed-altitude combination you calibrate from.
If what you care about is maximum true airspeed, you'd want a data point at or above the final critical altitude of the engine. Now there remains an obvious non-linearity - above critical altitude power falls, but so does drag as air density declines. Maximum speed is likely attained at some point just above critical altitude, depending on the airframe.
One thing I worry about is that if this flight test was run just once and the supercharger was sludging, the tax might be exaggerated.
Now I need to go back and re-read this thread...
-Blogs
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Hi Blogs,
>The cost of this precision however, is that the numbers won't match up with flight test data...
That's exactly what NACA meant. Engines in test aircraft are usually assumed to be performing correctly for the speed tests, but this assumption hardly ever is verified.
That's why the way of making speed predictions is to derive the drag from flight tests, then calculate a speed curve based on representative engine data.
Regards,
Henning (HoHun)
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Hi Blogs,
>The first and third charts seem to imply a supercharger tax on the engine between 2 and 4 km.
The FAF speed chart is not the result of mere morphing of the DB605A power chart due to ram effect. The FAF speed chart requries the minimum power in the variable-speed altitude band to drop 6% below the minimum power indicated by the DB605A power chart I'm using for reference (relative to respective maximum power).
>In this case it really does matter what speed-altitude combination you calibrate from.
I'm calibrating from speed at critical altitude. (I could use any data point below 2.4 km to get a virtually identical result, so this calibration is fairly robust.)
Regards,
Henning (HoHun)
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Originally posted by HoHun
You probably wouldn't learn much - it's like a one-dimensional flight simulation incapable of real-time operation, and I think you're already one or two steps ahead of that with your own project ;-)
Henning (HoHun)
Hi HoHun, nice thread.
However, I’m going to disagree on a couple of points, at least if we are talking about MS Excel, and probably with other spread sheets too if we checked. You can if you want, run a six degree of freedom, non linear aerodynamics model, with coupled total force equations of motion, solved using 4th order methods (for greater accuracy than you get in most sim’s) and all run in real time. You just need to use the high level language that comes built in. It is also quite possible to include graphics and I think early versions of excel had a fairly basic flight simulation Easter egg. It’s probably still there if anyone knows how to access it.
Why would you want to? Well if you want a state of the art simulation for game purposes, online or otherwise, you wouldn’t, but spread sheets are a very powerful tool, particularly if you are more interested in processing the output data for engineering purposes. Running a simulation and interrogating it in real time to produce graphs and other analysis can be one major advantage of building a simulation that runs in a spreadsheet. Another advantage is that you can build and run a flight model that way, fairly quickly, without investing the time required for a full blown simulation project. There are many other pros and cons of course, but I’m also fairly sure that HiTech is just pulling your leg, judging by the performance graphs on the HTC web site, I’d say he knows as much about the use of spreadsheets as we do :)
Badboy
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Hi Badboy,
>However, I’m going to disagree on a couple of points, at least if we are talking about MS Excel, and probably with other spread sheets too if we checked. You can if you want, run a six degree of freedom, non linear aerodynamics model, with coupled total force equations of motion, solved using 4th order methods (for greater accuracy than you get in most sim’s) and all run in real time.
Agreed, but it would not be my first choice for the job :-)
However, if you know anything about the tools the professionals use, that would be highly interesting!
Regards,
Henning (HoHun)
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blogs,
The throttle valve of the DB 605 is located between impeller and intake manifolds so below FTH there is more pressure between impeller and the throttle valve (gebläsedruck) than in intake manifolds (ladedruck). The MAP itself and control of the throttle valve is a fully automatic system ie pilot just selects wanted rpm and MAP combination and the system keeps these in wanted levels below FTH. The controll of the 2nd supercharger oil pump is simply by barometric valve which starts pump at around 2km.
I quess the best way to understand how MAP and pressure between impeller and throttle valve are connected, is to look power curve of the DB 605 and compare it to both pressure curves. The peaks of the power curve are located in same places where the relative difference between these pressures is smallest ie around 2,5km and FTH and above. Between these points pressure difference is higher and therefore relative efficiency decreases. Due to RAM effect this pressure difference increases at high speed flight, therefore efficiency is worse than in lower speed.
Overall it's up to you what you want to believe; documented stuff or something which might sound cool but is pretty much undocumented.
gripen
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"Now that could be used for making some aerodynamic comparisons... "
I've found that Daimler Benz chart useful for making comparisons.
Check the Spit V with Merlin 45 against this (http://www.fourthfightergroup.com/eagles/w3134.html) data set. Very good agreement.
Check the "Me 109 Serie" curve against the Mtt AG curves shown here (http://www.fourthfightergroup.com/eagles/spit9v109g.html). Again, very good agreement.
Compare the "Me 109 Serie" curve against some speculative estimates posted here. Hmmm, not so good.
Gripen, thanks for explaining Gebläsedruck. I couldn't figure that out. Its fortunate we have the Finnish trials data. Its interesting and valuable. I don't suppose I place quite as much weight on it as perhaps you do (shrug). I've admired your knowledge of the material, logic and clear presentation of facts in this thread. Nice job.
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Hi Mw,
>Check the "Me 109 Serie" curve against the Mtt AG curves shown here (http://www.fourthfightergroup.com/eagles/spit9v109g.html). Again, very good agreement.
Interesting data :-)
Is it correct that Werknr. 14026 achieved 364 mph @ 33000 ft?
Regards,
Henning (HoHun)
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There are known problems with using excel for ordinary least squares let alone nonlinear least squares.
-blogs
Originally posted by Badboy
Hi HoHun, nice thread.
However, I’m going to disagree on a couple of points, at least if we are talking about MS Excel, and probably with other spread sheets too if we checked. You can if you want, run a six degree of freedom, non linear aerodynamics model, with coupled total force equations of motion, solved using 4th order methods (for greater accuracy than you get in most sim’s) and all run in real time. You just need to use the high level language that comes built in. It is also quite possible to include graphics and I think early versions of excel had a fairly basic flight simulation Easter egg. It’s probably still there if anyone knows how to access it.
Why would you want to? Well if you want a state of the art simulation for game purposes, online or otherwise, you wouldn’t, but spread sheets are a very powerful tool, particularly if you are more interested in processing the output data for engineering purposes. Running a simulation and interrogating it in real time to produce graphs and other analysis can be one major advantage of building a simulation that runs in a spreadsheet. Another advantage is that you can build and run a flight model that way, fairly quickly, without investing the time required for a full blown simulation project. There are many other pros and cons of course, but I’m also fairly sure that HiTech is just pulling your leg, judging by the performance graphs on the HTC web site, I’d say he knows as much about the use of spreadsheets as we do :)
Badboy
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Originally posted by HoHun
Hi Mw,
>Check the "Me 109 Serie" curve against the Mtt AG curves shown here (http://www.fourthfightergroup.com/eagles/spit9v109g.html). Again, very good agreement.
Interesting data :-)
Is it correct that Werknr. 14026 achieved 364 mph @ 33000 ft?
Regards,
Henning (HoHun)
Yep, Werknr. 14026 in the DB601E/DB605A swapped engines test did 586 km/h at 10000m, farily low for the type, since the same plane when fitted with the much less powerful 601E engine did 580 km/h at the same altitude.
I guess there may be some problem`s with the 605A engine supercharger, given that it could attain the rated altitude in level flight, tested plane reached level speed VDJ height at 6100m instead of 7000m, and climb was even worser, VDH being only 5300m instead of 5800m.
Still, even this low performing Gustav at reduced boost (1310 HP) compares surprisingly well with the standard Spitfire IX at 150 octane fuel (1940 HP), their speeds at 20k feet being 626 km/h (Bf 109) and 624 km/h (Spitfire LF IX). This might give some idea for high speed aerodynamic effiency comparisons. ;)
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Hi Blogs,
>There are known problems with using excel for ordinary least squares let alone nonlinear least squares.
Interesting - I tried to use the "solver" to fit a curve through the scattered FAF data points using 3rd order polynom least squares, and it gave me a strictly linear graph. I decided not to believe that :-/
Regards,
Henning (HoHun)
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Hi Isegrim,
>Yep, Werknr. 14026 in the DB601E/DB605A swapped engines test did 586 km/h at 10000m
Rather funny! :-)
That's exactly the value I predicted for the FAF aircraft, and which Gripen found so impossible to believe that he accused me of data manipulation and forgery.
Regards,
Henning (HoHun)
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Hi HoHun,
That's exactly the value I predicted for the FAF aircraft, and which Gripen found so impossible to believe that he accused me of data manipulation and forgery.
Well, what can I say, typical of him. :/
Anyway, why not check your e-mail ? ;)
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Better to use Stata or Matlab.
-blogs
Originally posted by HoHun
Hi Blogs,
>There are known problems with using excel for ordinary least squares let alone nonlinear least squares.
Interesting - I tried to use the "solver" to fit a curve through the scattered FAF data points using 3rd order polynom least squares, and it gave me a strictly linear graph. I decided not to believe that :-/
Regards,
Henning (HoHun)
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Originally posted by joeblogs
There are known problems with using excel for ordinary least squares let alone nonlinear least squares.
-blogs
That's interesting because I've recently done both linear and non-linear curve fitting and used excel and done the calculations manually, and the results came out the same in every case. What are the known problems exactly?
Dweeb
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Originally posted by HoHun
Interesting - I tried to use the "solver" to fit a curve through the scattered FAF data points using 3rd order polynom least squares, and it gave me a strictly linear graph. I decided not to believe that :-/
Have you tried the "trendline" option for curve fitting? It seems to work very well.
Dweeb
PS, yes, I am a FSforum survivor from the late eighties, early nineties :)
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I referred to excel's stat features not to its other functions. The primary issue is numerical precision, which can be a problem when inverting matrices. I use excel all the time for other stuff, but not for regression work.
-blogs
Originally posted by Dweeb
That's interesting because I've recently done both linear and non-linear curve fitting and used excel and done the calculations manually, and the results came out the same in every case. What are the known problems exactly?
Dweeb
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Hello Hohun: good, the charts are clear enough. The following taken from the 3 German level speed curves should be interesting then:
Sea level speed
315 mph
316 mph
315 mph
“First Stage”
350 mph at 8,220 ft.
352 mph at 8,220 ft.
353 mph at 8,530 ft.
FTH
388 mph at 20,013 ft.
385 mph at 21,982 ft.
391 mph at 21,653 ft.
32,808 Ft.
364 mph
360 mph
360 mph
Looking at the level speed curves its apparent that the performance of the trials aircraft are within 5 mph throughout most of the flight envelope. That’s pretty darn good.
MT-215’s performance runs a bit stronger on average, by more than 5 mph up to FTH where it falls off.
Given the above data, the Russian data showing 670 km/h @ 7000 is not credible. Your acceptance and priortization of this data set, combined with your rejection of the documented german trials climb performance at 1.3/2600, points towards a need to refine your assumptions of the 109s aerodynamic efficiency.
It could be seen as a bit odd that you place such weight on Russian trials, of which the engine limits, aircraft configuration, and test parameters are unknown, when there is perfectly good German trials data available. It would also seem difficult for a spreadsheet model to allow a good fit for both the Russian and German curves.
Are you trying to calculate a theoretical, idealized 109G? Actually, I suspect your model might fit the German trials data reasonably well, give that a try. Use, for example, the German FTH average of 388 mph at 20,893 as your calibration point and see if your model generates 315 mph at Sea level. If so, then perhaps you are on to something.
I can see where reconciling the engine curves with performance trials could be useful in fabricating a model that could generate rough estimates. It’s a fine thing, and no doubt enjoyable for you to construct your estimates. I only take exception when you present them as fact. My apologies in advance if I’ve misconstrued your position. I’ve not had the time, nor sufficient interest in calculated estimates frankly, to give the thread my full attention.
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Originally posted by mw
MT-215’s performance runs a bit stronger on average, by more than 5 mph up to FTH where it falls off.
Given the above data, the Russian data showing 670 km/h @ 7000 is not credible. Your acceptance and priortization of this data set, combined with your rejection of the documented german trials climb performance at 1.3/2600, points towards a need to refine your assumptions of the 109s aerodynamic efficiency.
Of course it`s 'not credible', Mike, how could it be, : the results too good.
You deliberately choosed the worst figures you can find, for everyone that is crystal clear.
For the same reason the Finnish trials are ignored : first of all, even 640 km/h max. speed is too much for Mike, but even worse, there`s that damned Finnish climb chart, showing 4700 fpm climb rate. That`s on a 30min rating, not even at full power!
It wouldn`t fit into Mike`s agenda, and people would ask : 'Mike, you put the Finnish speed chart on, but why not the climb chart, too?' :D
But faster than a Spitfire? LOL, can`t happen in Miky boy`s head. :D Mustabe a cheat. In any case, hardly a problem, since the 109F-4 could already do 660-670 km/h, in other words, the 109 was already a good deal faster than any of the Spits variants a year later on in 1943, even when we ignore the fact how few of those Mk IXs actually saw service compared to the massess of old Mk Vs in 1943.
Like I said, the good fighters don`t need cheaters to help them out. :lol
Regarding the Bf 109`s aerodynamic effiency, not much to discuss on it.
The Bf 109G as according to the test could do apprx. 525 km/h at 1310 Ps, that would be something like 1285 BPH or so.
The Spit IX F at +15lbs and 1340 BHP at SL could do 502 km/h at SL.
Enuff said. Pitting the most successfull fighter of all times against an orthodoxly designed, all flying thing that never improved beyond the tech level of mid-30s aerodynamics isn`t really fair IMHO.
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It could be seen as a bit odd that you place such weight on Russian trials, of which the engine limits, aircraft configuration, and test parameters are unknown, when there is perfectly good German trials data available.
Glad to hear you have problems with that Mike. Now, pray tell, what are the exact conditions of the planes you call as :
"109 Serie Versuch Nr. 10 18 105 428 Daimler Benz"
Now what on Earth that could be ?
Or this one,
"109 VB Nr. 109 20 L43, Messerscmitt AG"
What model, G-1, G-2, G-3, G-4, G-5, G-6, a G-8or a G-14, a G-10?
What is the serial number of the plane, what do the report say of the external conditions, condition of the surface, loading of the plane, what corrections were used, Miky?
No, you don`t know any of these parameters, NOT ONE OF THEM, still you don`t bother to list the plane as a representative of the Gustav, yet start crying about the NII VVS live trials done with a known Werknummer, captured plane at known power boosting (1.42ata).
How pathetic Mike, your double standards wearing thin.
Come up with an asnwer, Mike. I don`t expect that to happen, you will cowardly run away, back to your little hide where you can m@sturbate wet dreams further on how much the Spitty is 'totally superior' in 'every respect', well, with a little help from Miky himself with the goal to fool the ones who can be fooled - which may turn out it`s only one person who satisfies his own needs in this way..
Uhm, I hurt ya, Mike ? Sorry `bout that, you know, the truth is what hurts the most of all things. :D
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Barbi, can you ever conduct yourself in a civil manner?
This is not one of your 'ambulance chaser' courtroom farces. The few Hungarians I have met are not as obnoxious and utterly ignorant as you are. Hopefully the other Hungarians are not cast in your mold. But, if one is a 'brown shirt' worshipper, your conduct is totally understandable, for sure.:aok
The only one that with an agenda is you and that is to try to convince people that the Messicrap 109 was the best se fighter ever designed and built. Sorry Barbi, it had its good points and bad points like every other a/c ever built.
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Hi Dweeb,
>Have you tried the "trendline" option for curve fitting? It seems to work very well.
I purposefully used the solver with hand-crafted formulae because I wanted full awareness of what Excel is doing :-)
>PS, yes, I am a FSforum survivor from the late eighties, early nineties :)
Nice to meet you (again)! :-) Great place, home to a lot of friendly and knowledgable people back in those times!
Regards,
Henning (HoHun)
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Hi Mw,
>Given the above data, the Russian data showing 670 km/h @ 7000 is not credible.
The discussion of Russian data can be found above in this thread.
>It would also seem difficult for a spreadsheet model to allow a good fit for both the Russian and German curves.
Actually, I get a satisfying fit for Russian and Finnish curves by merely using a different full throttle heights, along with the drag differences pointed out by several contributers.
>I only take exception when you present them as fact.
Well, scientific analysis is the only universally accepted way of arriving at facts.
(Divine inspiration works quicker and more accurately, but I can't use that here because it's not universally accepted ;-)
Be aware, though, that (unlike divine inspiration) scientific analysis is a lengthy process. I'm far from a final analysis of Me 109G data - in fact, I've hardly begun yet.
Regards,
Henning (HoHun)
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Since i have some access to Russian archives, here is the 109G-2 data as tested by the russians.
Alt / Speed / RoC
0K / 524 / 19
1K / 554 / 20.2
2K / 582 / 21
3K / 602 / 18.9
4K / 608 / 17.5
5K / 610 / 16.6
6K / 640 / 15.9
7K / 666 / 13.2
8K / 660 / 10.6
9K / 648 / 8.0
10K / 624 / 5.3
Time to 5000m : 4.4m
Weight 3023 Kg
Power at SL : 1310 ch
Power at 5800m : 1300 ch (!!!)
As a side note the full report is 17 pages long.
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Hi Butch,
>Since i have some access to Russian archives, here is the 109G-2 data as tested by the russians.
Thanks! :-) That's a nice surprise! Am I correct that the tested aircraft was W.-Nr. 14513 as I suggested earlier in this thread?
>Power at 5800m : 1300 ch (!!!)
Ah, there we have an important part of the explanation why the Russian aircraft was so fast. The standard engine would have just 1250 HP at full throttle height. (Low altitude power is almost on specification, though.)
The corrected figure for the Russian Bf 109G-2 with a 7 km full throttle height would be 657 km/h.
Is there any hint in the report how the 7 km full throttle height was possible?
(Did the Russian aircraft feature the retracted tail wheel? It certainly had a better drag condition than the Finnish aircraft.)
Regards,
Henning (HoHun)
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Hiyas, I had a hunch the Russians increased the RPMs above a certain height. Would that explain the FTH and speed?
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Hi Mw,
>Hiyas, I had a hunch the Russians increased the RPMs above a certain height. Would that explain the FTH and speed?
Good suggestion! :-) A similar technique was later used with the Bf 109K-4, so we should check that out. The RAE also tested their Emil that way, which is another precedence.
Hopefully, Butch's document will have the details so we can know for sure.
Regards,
Henning (HoHun)
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i have for 2600rpm:
1310hp@SL
1390@2300m
1300@5800
As for the aircraft tested, there are two of them : 13903 for the Cannonboat and 14513 for the regular version.
13903 achieving 650@7000m with gunpods @ 3235kg
Haven't got my way through the most cryptic parts of the report yet, but i believe that indeed tail wheel was retractable on both.
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Originally posted by HoHun
>Power at 5800m : 1300 ch (!!!)
Ah, there we have an important part of the explanation why the Russian aircraft was so fast. The standard engine would have just 1250 HP at full throttle height. (Low altitude power is almost on specification, though.)
I assume you simply took the static 1.3ata output at 5.8km and moved it to 7km to arrive at this, but that wouldn`t be 100% accurate, as the lower heat means also higher effiency of the s/charger at higher altitudes - just look at rammed speed figures, ie. I have those for the 601N, these show 1190 PS at 5.5km in static position, but when rammed this grows to 1230 PS at 1200 kg/m2 'Staudruck' !
So it isn`t just the same power at a higher altitude.
The corrected figure for the Russian Bf 109G-2 with a 7 km full throttle height would be 657 km/h.
I don`t think there`s need to 'correct' those figures any more. ;)
Is there any hint in the report how the 7 km full throttle height was possible?
(Did the Russian aircraft feature the retracted tail wheel? It certainly had a better drag condition than the Finnish aircraft.)
I suppose the clean (as factory standard) config is the key. As mentioned, (now that we know that the tailwheel on the Soviet plane was retractable) lower drag would mean higher achievable speeds, which mean more ram gain, and a result, higher critical altitude that on the other planes that were all flown with non-retractable landing gears.
By default, the G-2/G-4s tailwheel was retractable, unless it was late production model with the larger tailwheel.
Good suggestion! :-) A similar technique was later used with the Bf 109K-4, so we should check that out. The RAE also tested their Emil that way, which is another precedence.
I don`t think there`s RPM increase. Why would there be? Personally I think this new idea is only supposed to replace the "unknown conditions, thus ignore, ignore!" line after it crumbled.
Speaking of the 109K`s RPM increase at altitude, surely the climb/speed charts show it, but I am not sure of it`s true nature, wheter it`s something automatically happening above a certain altitude, or is it simply a case that over the FTH, the RPM can be manually increased by advancing the throttle further than 100% to reach to same 1.45ata Kampfleistung boost at 2800 rpm`s increased supercharger speed (at 2600rpm supercharging would be inaduquate to maintain that boost any longer)... I tend to believe the latter, but it`s just a guess.
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http://www.x-plane.org/users/hohun/me109g-2.jpg
That P-40 at 57" - is that calculated figures or realtest data ?
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Originally posted by HoHun
Hi Isegrim,
>Yep, Werknr. 14026 in the DB601E/DB605A swapped engines test did 586 km/h at 10000m
Rather funny! :-)
That's exactly the value I predicted for the FAF aircraft, and which Gripen found so impossible to believe that he accused me of data manipulation and forgery.
Here HoHun forgets to told that his calculated value 586km/h is for engine running at 2540rpm and tail wheel down. And he also forgets to told that the data he used was really manipulated (the evidence is above) and made his new curve to start from 200m higher than value in the FAF chart (which allready was 20km/h too high).
My estimate for MT-215 running 2600rpm and tailwheel in was 578km/h at 10000m.
gripen
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Hi Voodoo,
>That P-40 at 57" - is that calculated figures or realtest data ?
Calculated :-) However, I'm entirely confident it's more representative for a real P-40N-1 than any particular set of real test data.
(In fact, it's very close to one particular set of real test data where the engine didn't reach full boost at full throttle height. It appears a bit better than most P-40N-1 data around because it's based on a clean airframe with no bomb racks etc. However, it was cross-checked and confirmed by a real P-40N-5 data point for a very similar clean airframe. If you're interested in the 378 mph top speed sometimes quoted for the P-40N-1, that couldn't be confirmed, neither from real test data nor from calculations. I didn't personally do the research for the P-40, though, just the calculations that were used for the analysis of the raw data.)
The relation to the Me 109 analysis is that the P-40 and the Me 109 spreadsheets are the same. I simply entered new parameters and a new engine graph because I figured the laws of physics are just the same for both aircraft types :-)
Regards,
Henning (HoHun)
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Originally posted by HoHun
The relation to the Me 109 analysis is that the P-40 and the Me 109 spreadsheets are the same. I simply entered new parameters and a new engine graph because I figured the laws of physics are just the same for both aircraft types :-)
Here HoHun forgets to told that the parameters were wrong in the case of the MT-215.
gripen
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Hi Blogs,
>When I saw the origonal plots I wondered about the standard errors of these estimates.
The problem is that the Finnish test only measured speed over altitude, not power over altitude, and the engine was not performing in accordance with the DB605A power graph.
However, from observation of the full throttle heights and the drop of the power it's possible to arrive at an approximated power curve (using a 3rd order polynom) that can be used for further calculations in order to estimate the standard deviation.
Here is the calculated drag (relative to the average) for the full set of data from the Finnish table:
140 m: 95,3%
1130 m: 96,8%
2130 m: 96,5%
3120 m: 95,5%
4120 m: 96,6%
5120 m: 98,7%
6120 m: 97,2%
6420 m: 96,6%
7110 m: 109,7%
8110 m: 103%
9110 m: 95,4%
10100 m: 118,8%
Standard deviation: 7,2%
This gives the following data:
631 km/h @ 6420 m +/-11 km/h
581 km/h @ 10000 m +/-11 km/h
However, one look at the drag values should be enough to recognize that the data gathered above full throttle height is considerably less reliable than that gathered below full throttle height.
Standard deviation drops from 7.2% to 1.1% by simply disregarding all (four) values above full throttle height.
Here's the data resulting from that decision:
0140 m: 98,6%
1130 m: 100,1%
2130 m: 99,9%
3120 m: 98,8%
4120 m: 99,9%
5120 m: 102,2%
6120 m: 100,6%
6420 m: 99,9%
Not considered:
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7110 m: 113,5%
8110 m: 106,5%
9110 m: 98,7%
10100 m: 122,9%
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Standard deviation: 1,1%
635,6 km/h @ 6420 m +1,9/-1,3 km/h
586,0 km/h @ 10000 m +1,6/-1,6 km/h
Due to the incomplete nature of the Finnish test, this should be only taken as an illustration of the inherent inaccuracy of performance measurements.
>I think its under appreciated how noisy these numbers can be when only 1 or 2 tests are run under any set of parameters.
Well, the values below full throttle height are quite consistent in my opinion.
Above full throttle height, they're extremely poor, but considering that up there, the limited excess power up combined with the increasing difficulties of getting accurate measurements at high altitude, that shouldn't come as a surprise :-)
Regards,
Henning (HoHun)
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Originally posted by HoHun
The problem is that the Finnish test only measured speed over altitude, not power over altitude, and the engine was not performing in accordance with the DB605A power graph.
The problem with HoHun's (so called) analysis is that he continously refuses to use real tested value for the 10100m CINA ie 552km/h (for obivious reason) seen here:
(http://personal.inet.fi/koti/soon.moro/Clipboard.jpg)
Hohun's entire analysis above FTH is based on one errorneous value in the FAF graph (http://personal.inet.fi/koti/soon.moro/Clipboard1.jpg). Basicly he picks up the value which supports his agenda and ignores the rest.
gripen
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Actually output of the MT-215 can be estimated by using RPM and MAP values from the test data (http://personal.inet.fi/koti/soon.moro/Clipboard.jpg) and comparing it to the RPM and MAP values of the DB Spitfire:
(http://personal.inet.fi/koti/soon.moro/Clipboard2.jpg)
Up to the FTH output difference between 2600 RPM and 2540 RPM is pretty much directly relative to the RPM diffrence because MAP is same. Above FTH lower RPM also affects MAP making relative difference bigger.As an examples
MT-215
6420m CINA 2540rpm 1,3ata => about 1221ps
10100m CINA 2540rpm 0,74ata => 690ps (measured by comparing to the DB Spitfire climb data).
DB Spitfire
6420m CINA 2600rpm 1,3ata => about 1255ps
10100m CINA 2600rpm 0,81ata =>about 800hp (measured by comparing to the DB Spitfire climb data).
So at FTH output diffrence between 2540 and 2600rpm is just about 30-40ps ie around 3%. But at 10100m the output difference is about 15%.
gripen
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Here is the DB Spitfire climb data to use for output estimates:
(http://personal.inet.fi/koti/soon.moro/DBSpit2.jpg)
And here is the DB 605 output chart. Note that the chart is with about climb speed RAM, this can be easily verified by looking FTH for 1,3ata 2600rpm; it's 5800m in the climb chart and in the output chart.
(http://www.allaboutwarfare.com/files/uploads20/1084205497bh3pt.jpg)
The output of the DB Spitfire at high speed and at 10000m can be estimated by looking MAP value in the DB Spitfire chart which is about 0,84ata. Then by looking the MAP value in the climb chart it can be seen that at climb speed MAP has value 0,84ata at about 9500m. After that output can be measured easily by looking output chart at 9500m and the value there is about 800ps.
gripen