Author Topic: Me-109 turn to right widely said to be poor; any clues?  (Read 9720 times)

Offline Die Hard

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Re: Me-109 turn to right widely said to be poor; any clues?
« Reply #30 on: March 28, 2009, 10:53:24 PM »
"The range would be further increased with the introduction of an 85 gallon self-sealing fuel tank aft of the pilot's seat, starting with the B-5NA series. When this tank was full the c-g of the Mustang was moved dangerously close to the aft limit, as a result of which maneuvers were restricted until the tank was down to about 25 gallons and the external tanks had been dropped. Problems with high-speed "porpoising" of the P-51Bs and Cs with the fuselage tanks would lead to the replacement of the fabric covered elevators with metal covered surfaces and a reduction of the tailplane incidence." [Gruenhagen, 1980, p.91.]
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Offline Chalenge

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Re: Me-109 turn to right widely said to be poor; any clues?
« Reply #31 on: March 29, 2009, 01:16:48 AM »
Chalenge,

Pages 7 and 75 http://trainers.hitechcreations.com/historical/P-51%2051-127-5.pdf  which by the way is posted on the P-51D AHWiki page.  That is not to say that the significance that is being placed on that topic in this discussion is anything short of misguided and misleading.

I cant seem to get to the link you posted. Everything in the link Gaston referenced (MustangsMustangs.com) is very nearly a direct quote from Detail & Scale except for this bit: Metal elevators were added in February 1945. The P-51D continued to have a fabric rudder. Of course every Mustang I have ever seen has a metal elevator and that includes B & C models so I want to see/hear this from a reliable source and not the internet.
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Offline Die Hard

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Re: Me-109 turn to right widely said to be poor; any clues?
« Reply #32 on: March 29, 2009, 01:35:49 AM »
It is better to be violent, if there is violence in our hearts, than to put on the cloak of nonviolence to cover impotence.

-Gandhi

Offline Chalenge

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Re: Me-109 turn to right widely said to be poor; any clues?
« Reply #33 on: March 29, 2009, 01:42:08 AM »
Thanks DH I will order that and see what I can learn from it.  :aok
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Offline Murdr

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Re: Me-109 turn to right widely said to be poor; any clues?
« Reply #34 on: March 29, 2009, 01:48:41 AM »
I cant seem to get to the link you posted.
Give it minutes to load, or right-click save as...  It is a 46.5Mb file (Original scan 1945 USAAF manual.)
Links to historical documents (Pilot's notes, training manuals, flight operational manuals, ect.) added to the following aircraft pages.

http://bbs.hitechcreations.com/wiki/index.php/P-38G
http://bbs.hitechcreations.com/wiki/index.php/F6F-5
http://bbs.hitechcreations.com/wiki/index.php/Tempest_Mk_V
http://bbs.hitechcreations.com/wiki/index.php/Spitfire_Mk_IX
http://bbs.hitechcreations.com/wiki/index.php/P-39Q
http://bbs.hitechcreations.com/wiki/index.php/P-38J
http://bbs.hitechcreations.com/wiki/index.php/P-38L
http://bbs.hitechcreations.com/wiki/index.php/Typhoon_Mk_I
http://bbs.hitechcreations.com/wiki/index.php/P-51D
http://bbs.hitechcreations.com/wiki/index.php/P-39D
http://bbs.hitechcreations.com/wiki/index.php/P-47D-11
http://bbs.hitechcreations.com/wiki/index.php/P-47D-40
http://bbs.hitechcreations.com/wiki/index.php/P-47D-25
http://bbs.hitechcreations.com/wiki/index.php/P-47N
http://bbs.hitechcreations.com/wiki/index.php/Mosquito_Mk_VI
http://bbs.hitechcreations.com/wiki/index.php/Me_262
http://bbs.hitechcreations.com/wiki/index.php/B-25C
http://bbs.hitechcreations.com/wiki/index.php/F4U-1D
http://bbs.hitechcreations.com/wiki/index.php/F4U-1
http://bbs.hitechcreations.com/wiki/index.php/F4U-1A
http://bbs.hitechcreations.com/wiki/index.php/F4U-1C
http://bbs.hitechcreations.com/wiki/index.php/FM-2
http://bbs.hitechcreations.com/wiki/index.php/F4F-4


Note:  A few .pdfs are tens of megabytes, and are not optimized for downloading.  They will eventually (several minutes) load and display in a browser, or you can right-click to save.

« Last Edit: March 29, 2009, 01:57:51 AM by Murdr »

Offline B4Buster

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Re: Me-109 turn to right widely said to be poor; any clues?
« Reply #35 on: March 29, 2009, 07:52:47 AM »
As Sunsfan said the 109 performs poorly when you roll it to the right at the top of the loop, the pony is equally as bad. It's a brick when you get it into a rolling scissors fight and go to roll to the right  :O

Gaston if I remember right you haven't plyed AH before right? I think you should do a two week trial and see what the plane modeling is like. I think you'd be surprised.
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Offline Murdr

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Re: Me-109 turn to right widely said to be poor; any clues?
« Reply #36 on: March 29, 2009, 01:40:35 PM »
The AHWiki description is obviously based on wingloading and aerodynamic formulas; the result is totally opposite in almost all respects to the real aircraft

Quote
PTR-1107 February 1944

TURNING CIRCLES - Results of comparative tests of turning characteristics showed the F4U-1 and F6F-3 to be far superior to the FW-190.  BOth the F6F and F4U could follow the FW-190 in turns with ease at any speed, but the FW-190 could not follow either of the other two airplanes.  The FW-190, when in a tight turn to the left and near the stalling speed, exhibits a tendency to reverse aileron control and stall without warning.  Similarly, when turning to the right it tends to drop the right wing and nose, diving as a result.

From a head-on meeting with the FW-190 both the F4U-1 and F6F-3 could be directly behind the FW-190 in one turn.  From a position directly behind it was possible to turn inside the FW-190 and be direectly behind again in about three turns. 

MANEUVERABILITY - The F4U-1 and F6F-3 were found to be much more maneuverable than the FW-190.  No maneuvers could be done in the FW-190 which could not be followed by both the F4U-1 and F6F-3.

It was found that the FW-190 requires a much greater radius in which to loop than do either the F4U-1 or F6F-3, and tends to stall sharply when trying to follow the F4U-1 and F6F-3 in a loop.

In zooms after dives the FW-190, F4U-1 and F6F-3 were found to be about equal.

THe FW-190 stalls with very little warning, but recovers easily.

Quote
In any case, I was interested in finding out about the REAL aircraft's flight assymetries, so a game or calculated figures are not really relevant.

Here is a developers screenshot showing just a portion of the many points of force that are simultaniously being calculated in real time from the flight model.  That's 32 independent lift calculations across the main foil cords alone.

Your continuing dismissive attitude toward the laws of physics, underestimation of flight modeling in general by a factor of a magnitude, and assertions based on flawed understandings is a bit ridiculous.


Gaston if I remember right you haven't plyed AH before right? I think you should do a two week trial and see what the plane modeling is like. I think you'd be surprised.

B4's suggestion is a good one.  At the very least you might learn a bit of pratical knowledge about ACM techniques.  Something your posts indicate you misunderstand quite a bit about.
« Last Edit: March 29, 2009, 01:42:10 PM by Murdr »

Offline BnZs

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Re: Me-109 turn to right widely said to be poor; any clues?
« Reply #37 on: March 29, 2009, 02:40:38 PM »
Post the bit about 190 dive performance from that same report for all to see if you don't mind Murdr.

The 190 perhaps handles dives and maintain elevator authority a bit better in AHII than the actual flight tests would seem to indicate. I have no qualms about taking a 190 to 500mph IAS, vs. the r/l 460 limitation. However, every plane in the set seems to handle speed and maintain control authority at high IAS abit better than I would expect from my research, so it is not a quirk of the 190 flight model.

Here is a developers screenshot showing just a portion of the many points of force that are simultaniously being calculated in real time from the flight model.  That's 32 independent lift calculations across the main foil cords alone.
(Image removed from quote.)
Your continuing dismissive attitude toward the laws of physics, underestimation of flight modeling in general by a factor of a magnitude, and assertions based on flawed understandings is a bit ridiculous.


B4's suggestion is a good one.  At the very least you might learn a bit of pratical knowledge about ACM techniques.  Something your posts indicate you misunderstand quite a bit about.
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Offline Gaston

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Re: Me-109 turn to right widely said to be poor; any clues?
« Reply #38 on: March 30, 2009, 04:09:04 AM »
    Just to get the metal P-51 elevators out of the way...

    Gruehagen's description of the reason for their introduction does not jive with numerous sources I have read that placed their introduction very late in WW II, at least for the European theater. Also the rear fuselage tank weight balance issue seems an odd reason for stiffening the elevator's surface. Note ALL post-war P-51s, including B and Cs, could very well display metal elevators WITHOUT this being relevant. In any case, the Potter-owned Mustang IV, at "Vintage Wings", is described on their website as having fabric elevators, which could also be wrong!

    I mentionned metal elevators only as a counter to the odd combat account that might show superiority in 500 MPH dive pull-outs against the generally superior Me-109 moveable tail. In any case Me-109 pilots most often did not remember to trim tail-heavy in the dive, hence the baseless legend of impossible pull-outs (In fact, an actual strenght of the type!)...

    BnZ says I mention tests nobody has ever heard of, well here it is; the test most relevant to my argument of poor 190 handling at high speed vs P-47D-4 (and of increasing P-47D turn rate past 250 MPH!). I did mangle some of the wording, but the points all bear out my claims;
           
           http://img107.imageshack.us/img107/9568/pag17bm.jpg
       

       - (Below 250 MPH)"Turns were made so rapidly it was impossible to accelerate, and the ability of the FW-190 to HANG ON ITS PROPELLER and turn inside the P-47D-4 was very evident"

       - (Above 250 MPH)"The P-47 EASILY out-turned the FW-190.... This superiority increasing with altitude. The FW-190 was very heavy in fore and aft control, (Me; possibly not exclusively a stick weight meaning? Since not "on the controls") vibrated excessively, and had a tendency to black out the pilot" (This last is odd, and suggest to me stick response was not progressive, but instead delayed with noticeable mushing that would be followed by a sudden "pitch up" leading to this comment.)

       Incidently, I happen to believe the delayed response to elevator input control is obvious from much WW II footage depending on speed, and is probably a great unexplored area of WW II aircraft performance... Pilot/stick, stick/pitch, and pitch/trajectory are all areas of large variables in my opinion for elevators. Ailerons are much more predictable and quantifiable; they fight much less weight/leverage, and roll rate charts are thus usually more representative.

      Returning to the comparative turn test, NO mention is made of a speed zone of relative equality in turns, which I find VERY telling. To me this probably means the P-47's turn response is STILL improving past 250 MPH, while the FW-190's is rapidly descending. Recent (1990!) tests of the P-51 and P-47 found the pilots saying the peak turn rate was MUCH higher than they expected, leading them to conclude that low speed turn performance was probably not that good...

      Now note; "The airplane (FW-190) is quite nose-heavy, which makes dives near the ground dangerous". I mean... With Eric Brown's "addendum" to his see-saw tactic description ("EXTREMELY vulnerable on pull-outs"), the Russian's "perfect target" while "hanging" on pull-outs, U.S. pilots describing an 8000 ft. minimum to start pulling out or else... The INNUMERABLE descriptions of "pankaking" 190s, of which not one I remember concerning the 109... There IS a pattern here...

      I think YES the 190 could pull 7Gs on pull-outs, but there could be a very long "lag-time" for that response to happen, and even when it DID happen, much of those Gs could have been generated in deceleration by an abruptly shifting, "automatic" tail-down "sinking", not turning, leading to the following inferior performance compared to an aircraft not immune to "sinking" itself!;
     
                "The P-47D-4 had a DECIDEDLY better angle of pull-out." Suggesting the nose-heavy 190 wanted to stay flat.

      Aside from Kurt Tank's 7G pull-outs on tests, which is quite well explained by the sudden "blackout" pitch tendency described in the test (following the lag-time of control response), I am really at a loss to explain where is there ANY evidence of great high speed FW-190A behaviour from actual flight tests, or from any combat report except when going straight...

      The comparative with the F4U-1 and F6F-3 is very interesting, if a bit sparse on speed data. The equality in zoom after dives is interesting, and a potential counter to my point, but neither of the american aircraft were known for their zoom (the Ki-61 would out-zoom the F4U-1!), so the ability of the 190 to retain speed in the climb could have brought it to equality against these unimpressive zoomers... Also note that Eric Brown admonishes that careful pitch control allows pulling-out without "killing speed" by sinking, so we don't know if ONLY the height reached was used as the measure of the zoom performance, without considering the lenght. I don't think a test against the P-47D, P-38L and P-51D would have led to these optimistic zoom parity results...

      That the F6F-3 out-turns the FW-190A-5 should be a surprise to no one; it was the only late american aircraft to tangle regularly with the Japanese, probably equal to most late Spitfires... The F4U-1 is an unknown quantity to me, but a factor should be remembered here. The actual FW-190A-8 ace on this Forum mentionned "catching" the stall with the ailerons, after a slight forward push on the stick, choosing extra aileron chord to boost this, boosting this further with SPACERS, having the broad wood prop, etc... You don't think American test pilots were that well versed in those shenanigans, do you?

      Also THAT pilot, plus many others from several sources, ALL say the FW-190A-8 was a MAJOR advance in maneuverability over ANY previous model. You cannot assume just because it was heavier it did less well, which brings me to a possible alternative I found to wingload calculations;

     http://www.sci.fi/~fta/JohnBo1.jpg

     This is a turn rate performance chart from actual flight data comparing the heavier F-86 Sabre to the lighter Mig 15, both maximum and sustained. Josf14, in the following thread, makes quite a messianic point that this actual data chart goes against every precept of wingloading calculations, because the heavier/weaker thrust F-86 beats the lighter more powerful Mig-15 at low speeds in maximum turn rate.

     If you forgive his difficulties with the English language, and his strange style of expression, I think he has quite a valid point. Here is the entire thread, hopefully, from the "FW-190 consortium" forum;

      http://acompletewasteofspace.com/modules.php?name=Forums&file=viewtopic&t=8470

     Of couse the countering argument is that a myriad of reasons could explain this "physical impossibility". He explains it as the extra weight allowing better speed retention throughout the turn, increasing the amount of air being moved out of the way in a given time.

     I don't know. My theory is this, for all it's worth; heavier aircrafts, up to a point, have the equivalent of a higher center of gravity compared to the center of aerodynamic pressure; AS IF they were sitting more "top heavy" on a soft medium; this gives them an extra leverage, or tendency, to orient their axis of thrust OFF CENTER to their trajectory. This would mean the axis of thrust is at a SLANTED angle, meaning the axis of thrust is hitting SLOWER air relative to itself. This would increase the thrust more than the low-speed friction cost of being at too high an angle of attack. A primitive form of vectored thrust in other words...

     Now I hasten to add this is just an impression planted in me by the expression "hangin on the prop", which in fact you encounter frequently when reading on the FW-190...

     What I DO know for sure, is that an actual wartime FW-190A-8 Western ace said, on this very forum, that the A-8 model was a major advance in maneuverability over all previous Antons, with concurring opinions from other pilots about the very same variant elsewhere. (I think the main advance was due to the increase to a standard 1.58 ata power rating).

     If you want to believe they bent the laws of physics improving those turns, apparently the laws of physics don't agree...

     Gaston.

     
     

     
   

   

   
« Last Edit: March 30, 2009, 06:41:21 AM by Gaston »

Offline mechanic

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Re: Me-109 turn to right widely said to be poor; any clues?
« Reply #39 on: March 30, 2009, 05:21:56 AM »
Gaston, with respect I think the vast majority of the real pilots back then never came close to understanding the full potential of any one aircraft. A pilot who shot down many spitfires in a 109, or flight tested a post-war Fw190 may easily come away with a factual and yet hardly scientific opinion of any given aircraft in terms of equal advantage combat.
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Offline Gaston

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Re: Me-109 turn to right widely said to be poor; any clues?
« Reply #40 on: March 30, 2009, 06:35:08 AM »

     Note; the link to the P-47D vs FW-190 report broke when I corrected a typo.

     I cannot find it again.

     This comparative test was titled as such;

                     
                     Aeronautical Research Committee.                   

                     Stability and control  sub-committee.        S.&C. 1718.               April 24 1944.


        If someone can fix the link (it is the first in my last post) or find it, it would be appreciated. This test report is NOT available at the "WWII aircraft Performance" site.


       Gaston.

               

Offline Gaston

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Re: Me-109 turn to right widely said to be poor; any clues?
« Reply #41 on: March 30, 2009, 06:48:14 AM »


      Found it and fixed it...

      The link to the F-86/Mig-15 turn chart is still broken, but the same chart is at the top of the "Games vs Reality" thread link, and I'm not touching this post again!

       Gaston.

Offline mechanic

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Re: Me-109 turn to right widely said to be poor; any clues?
« Reply #42 on: March 30, 2009, 07:12:50 AM »
Sorry i was thinking along the games line more than reality when it comes to this forum. Was not trying to start anything more.
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Offline Charge

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Re: Me-109 turn to right widely said to be poor; any clues?
« Reply #43 on: March 30, 2009, 07:19:29 AM »
"He explains it as the extra weight allowing better speed retention throughout the turn"

I have though of that idea too and it might be possible if the AoA is kept at moderate levels, otherwise all that mass and energy would be used to practically stall the wing through turn resulting in quick deceleration (i.e. mushing through turn or in dive pull-up). One other idea I have read from someplace was that small wing increases energy retention by posing a smaller drag area (with AoA) in high speed than a bigger wing. That too might hold water if, again, the AoA is kept at moderate levels.

In practice I have sometimes noticed in AH that since even 190A8 is relatively fast at low level fights missing the other elevator ofter increases my chances of survival because I cannot "dump energy" on a whim as I normally do.  :lol

But comparing e.g. Spit 9 and 190A8 in landing the Spit9 decelerates rather quickly without power where as I need to slide and wiggle the A8 a lot to dump the energy to even get gear out for the landing. I'm not sure that if the drag figures are that different without power how the Spit can make up all the difference with engine power when on full power. One possibility is that while at low AoA the Spit has relatively low thickness of the wing (13%) it can go fast but it might bleed energy heavily in high speed turns but again when it decelerates further the engine thrust comes more on par with the drag and it gains the ability to hold a tight turn in very slow speed. In practice this would mean that in a high speed engagement a 190 could make the Spit bleed out is energy by doing a series of high speed turns with low G trusting that with a bigger wing area, and less weight the Spit would actually lose quicker its momentum due to more drag that it could make it up by trying to cut the corners. Disclaimer: This is just an idea, don't take it too seriously.  ;)

One more interesting feature about 109 and 190 is that they fly "tail high" which tells something about their thrust-line so that in maneuvers the thrust is vectored a bit more lower than in planes that flew tail low. Considering the prop flow and how it energizes the flow over the wing in near stall situation I have no idea if it is a more optimal solution than others, but I think that even if it could be its effect could be negligible.

-C+
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Offline Gaston

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Re: Me-109 turn to right widely said to be poor; any clues?
« Reply #44 on: March 30, 2009, 08:38:52 AM »

     Interesting idea about the tail-high attitude, Charge!

     I myself have been wondering if the square wingtips don't bring more lift by leverage, because a broader wing surface area further away from the weight of the fuselage would have more "leverage" against that weight, maybe delaying the true stall and allowing a more prolonged "mushing" behaviour while a pointy tip wing would have stalled outright.

      In any case, my link to the P-47D vs FW-190A was incomplete; here is the most relevant part in the original document form. I consider this test one of the most informative aircraft comparisons I have ever read, full of intricate unexpected details. I find it surprising it is so hard to find...:

                      http://img105.imageshack.us/img105/3950/pag20pl.jpg


      The first part; http://img107.imageshack.us/img107/9568/pag17bm.jpg


       I couldn't put it back in my original post...  As with the FW-190A-8 ace's descriptions six years ago on this forum, the results are consistent and illuminating.

      As for the very interesting video about the 109G airshow pilots discussing its turning ability versus the P-51D, I had seen it.

      Note that I never claimed the P-51D definitely out-turned the 109G below 250 MPH, and certainly NOT while climbing below 20 000 ft.

      If the spiral is slightly descending, however, I think, with flaps, the P-51D can be thrown about in such a way that it will catch up briefly even at speeds below 250 MPH, but the risk of a stall is great, and the gain will be fleeting. Airshow pilots would not try this...

      Under some circumstances, it seems, specifically at speeds above 250 MPH, but below 420, and maybe ONLY to the right, the P-51D has several anecdotes of gaining 360° in 720°, or even in 360°, against the Me-109G-6. This is an incredible rate of gain against a lighter aircraft, and the fact that I know of several anecdotes where the 109's tail position was reversed in one or two turns, so far always to the right, suggests that it is more than just pilot incompetence or exaggeration, as even if you halve the performance gap to four 360° turns, it is still a pretty quick way to gain a whole 360°...

      I don't think the 109's turn rate was inferior across the board to the Mustang, but I do note the Luftwaffe considered it close to, or less, maneuverable in turns against the 190 at low altitudes. At low altitudes it was considered close at any rate, which is not what you would expect. A larger assymetry in turn ability to one side might account for this anomaly, especially against the Mustang pilot's descriptions.

      I general, in combat reports below 20 000 ft., one definitely gets the impression the FW-190A matches the P-51D's turn rate more often than the Me-109G. At higher speeds though, the 190A is very poor;

       http://www.spitfireperformance.com/mustang/combat-reports/20-murrell-2dec44.jpg

      Note the ellongated loop, and the significance of the 400 MPH speed at the end(!).

      Gaston.