Aces High Bulletin Board
General Forums => Aircraft and Vehicles => Topic started by: Gaston on January 31, 2009, 08:16:00 AM
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Hello everyone, I'm Gaston Marty, the designer of an extensive re-vamp of the old Avalon Hill "Air Force" boardgame. It is called "Advanced Air Force", and you can see and print it for free at "Mike's Air Force Dauntless web site";
http://www.visi.com/~mrowles/Mike%27s_Air_Force_page.html
This re-vamp of this old "outdated" game took place over about fifteen years, so although the original information in the original game was very poor, don't confuse your memory of this game with this version. Mine was finished in 2007, with 2007-current research...
Since much of the information I used in the color Data Cards came from this very forum, I thought it would be appropriate to chime in with some observations based on the discussions I read here, especially regarding the aircraft performances as described in AHWiki.
To begin with, although the performance increments in a boardgame are by necessity coarser, especially for the speed, there are general trends in performance that can be counter-intuitive, and I always made sure to keep an eye out for those. I don't play Aces High, so keep in mind my observations are based on six years of observing this forum, and recently reading AHWiki's performance descriptions.
One basic thing worth pointing out, is that maneuverability occasionally does improves dramatically, and continuously, with speed; the boosted-aileron P-38L, for instance, rolled faster and faster the higher the speed, to the point of nearing 100° per second at 440MPH TAS. At low speed it was a poor roller even with boosted ailerons. This is Lockeed data, and is absolutely unique in WWII, and not mentioned in the AHWiki profile...
The P-51B and Ds achieved their best turn radius above 350 MPH, from much worse at low speeds, but the heaviness of these responsive high-speed elevators caused serious problems to the pilot above 450 MPH, to the point where at these extreme speeds, above 420 MPH, a 109 correctly trimmed tail-heavy would fairly easily out-turn it, as the 109's flying tail was outstanding in this respect, a point also noted by the RAF. North American engineers recognized this as one of the few superior points of the 109, and thus adapted the flying tail concept to the Sabre...
My intended point is, there are few things in aircraft performance that are as non-linear, unpredictable, and full of myths, as maneuverability...
For instance, torque has an effect on roll in one direction at low speeds, BUT at higher speeds, it is the slipstream of the prop wash spiral that has an effect on roll, ALWAYS in the opposite direction to the low speed torque effect. From aircraft type to aircraft type, the magnitude of variation varies greatly for both effects.
I will point out a few oddities that I found in AHWiki's performance descriptions. These comments have NO bearing on the game itself...
FW-190A-8: In AHWiki, the emphasis on the 190's high speed maneuverability is probably based on a Kurt Tank comment of very light elevators producing x Gs for each pound of pulling effort on the stick. These Gs are probably of short duration, OR due to the aircraft DECELERATING nose-up while still going down. ALL combat anectotes and side-by-side comparisons demonstrate a good initial nose-up response followed by severe mushing at high speeds. Against U.S. aircraft, the FW-190A was a medium to low speed TURN fighter, and every displaced Eastern front ace was advised to ALWAYS turn against U.S. fighters, and to NEVER use the vertical. This applied to the 109 as well. With a broad wood prop and extended chord ailerons, the A-8 was the ultimate turn-fighting A-series 190; this I found out in this very forum, from someone who knew personally an actual 190 Western front ace... The wing-drop stall made it very assymetrical in turning ability, depending on whether the flaps were dropped or not; the "good turning side" was the same as the wing drop side, and reversed according to the flap position, up or down. Apparently, a low speed turn with down flaps would be better to the right, and the powerful ailerons could be used to "catch" the stall, making the FW-190A-8 a passable low-speed stall fighter!
Another point, worth emphasizing, is the supremely good high altitude dive performance of the 190, marred at low altitude by the necessity of beginning the pull-out extremely early (8000 ft.!)to avoid the consequences of the severe mushing-then-pancaking tendencies... NOT a high speed fighter this is, unless there is height to keep going...
Spit XIV: From the Mk IX onwards, the Spitfire's roll rate became less than two-thirds of what the Mk V could achieve, and this with the SAME early peak in the speed range, that is, of around 200 MPH TAS(!). The Mk V's highest roll was about 70-78° per second at this 200 MPH TAS point. The Mk IX was 2/3rds of that according to the Supermarine's factory test pilot, so about 50° per second, getting WORSE afterwards... The Mk XIV was slightly worse than this, with the SAME early peak, as is borne out by MK XII roll data, which indicates a peak of 35-40° per second at 200MPH TAS. Outlandishly, Farnborough's well-known side-by-side tests indicate a "generally" superior roll rate for the MK XIV versus the P-51... If you search VERY long on this absolutely bizarre claim, you will find a comment saying "The MK XIV's ailerons were defective but will be fixed in production". THIS is what besting the P-51's roll rate is based on; a test pilot's wishful thinking... A major feature of most Spitfires is in fact slow ailerons, leading to the Galland comment; "great for aerobatics, but ridiculous for fighting". Clipping the wings helped moderately at low altitudes mostly, and the MK V's 78°/sec. at 200 MPH could be the top Spitfire figure if clipped, as 60-70°/sec. seemed common. This would put the MK IX peak at a 40-45°... Obviously, the NACA 868 roll chart's Spitfire figures are not valid for any mass-produced wartime Spitfires...
Another feature of all Spitfires is a slow initial turn, getting worse at high speed, because a movement of the stick top of more than 3/4 of an inch will cause it to mush forward in a controlled stall. This could be used to gain a firing lead, mind you, but at a great loss of speed or at the risk of "bending" the aircraft at high speed. Though very useful offensively, this is not really an impressive feature of the turn for escaping a pursuing ennemy, and it demonstrates a remarkably poor lift for such a large wing... The high altitude dive speed mach number is outstanding, but at low altitude it is the rigidity of the wing against buffeting, not the mach number, that makes a good diver. The Spitfire does no better than the 109's fluttering ailerons below 20 000 ft..
ME-109G: AHWiki claims the best maneuverability is between 250 to 400 MPH; true for roll, but for the G and later variants, it is completely and utterly the opposite for turn and elevator response! Concerning the G, the pilot's manual warns the pilot of a more than DOUBLING of the turn time from 250 MPH TAS to 280 MPH TAS! This could be alleviated by trimming it very tail-heavy, but the nose-down "tuck" that causes the problem, as the aircraft crosses 250 MPH or so, takes an extra amount of downward tailplane drag to alleviate and improve the nose-up response; this in theory equals poorer speed retention in turns. Above 400 MPH, the tail-heavy trim starts working well again, because the volume of the faster air, or the increased wing or nose lift, allows crisper pulling on the "mushiness" of the 250-400 MPH nose-tuck tendency. At 450 to 500 MPH, the pull-out and turn performance of a tail-heavy trim 109 is superior to a P-51B or D(several combat anecdotes), but the P-51 can go to 550 MPH, something the 109 can't match.
Me-163B: No emphasis in AHWiki on the fact that the Me-163B climbs FASTER and FASTER as the altitude increases! At 40 000 ft the Me-163B's climb rate is almost DOUBLE what it is at 10 000 ft! This unique feature is due to the decreasing air density that does not affect the non-breathing rocket engine. I have heard the figure that, at this high altitude, the horsepower equivalent is 9000... The Me-163 had a good wingload EMPTY, but the turn performance varied in minutes as burning fuel halved the weight(!). Empty or not, the design had a lazy pitch response, like all tailless designs, but roll was optimized for high altitude and excellent, although it apparently became heavy and lazy at low altitude(this from a well-known P-38 combat account)...
P-47 Razorback: No AHWiki emphasis on turn and roll assymetries, which are a feature of the type, as well as on the importance of high speed for crisp maneuvers. Initial lazy response in the turn is a feature of the type, but less so at low altitude, high speeds, and to the left, if the pilot is gentle on pulling the stick. Like the Spitfire, overly light elevators at high speeds causes mushing if the pilot pulls too much.
While I am on this subject, stay away from Robert Jonhson's claims of 470 MPH TAS at 30.000 ft. for his "Hot Rod"...
In any case, maybe this will clarify some points, if you visit "Mike's Air Force Dauntless", and find the aircraft performance data of my "Advanced Air Force" variant to be strange and unexpected. I have found this forum to be by far the most useful of all in making this game, so I hope some of you will enjoy comparing the cards, even if you play in another medium!
Gaston.
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Thanks Gaston.
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:rock
wow that's impressive.
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Excellent stuff Gaston. After reading and then later researching WW2 aerial combat, pilots and airplanes I have certainly found it so true, that the more you think you know, the more you know you don't know. There are so many urban myths and glaring errors in the "general" knowledge about WW2 aviation, as well as little or barely known surprising details under the well known facts. Every new book, every interview always brings new surprising things to think about. Your post gives some very interesting new things to ponder at.
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Wow... GREAT info! Thanks! :salute
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Galland's comment was based on the Spitfire's float carburetor at the time. All tests I have seen put the Spitfire Mk I's roll rate as equal or better than the Bf109E-4's, though both got better later in the war.
Do you have an documentation to back up your claims about the Spitfire? Your casual dismissal of the NACA chart is suspicious.
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Now the question is...
will anything get acted upon once the next step is deleivered? ;)
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I doubt it will be delivered. His take on it that Spitfires were helpless crap does not match the wartime record at all.
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A great deal of this stuff Gaston posted does seem odd and out-of-sync with pilot reports I've read.
I will agree that indeed our pilot in AHII seems to laugh at the high control forces some sources describe for certain planes at certain speeds, but his Ah-nold upper-body strength at the controls is probably not beyond the scope of human exertion and is consistent for all planes across the board. He may have no trouble pulling to blackout in a 109 at 300mph IAS for instance, but then again he can haul a P-51D around at any speed short of mach .65 or so very well, despite the fact that the Mustang purportedly didn't have the lightest control surfaces at very high IAS either.
Of course, IMO a big edge in control authority starting at ~300 IAS would be far more useful than one starting at at 400mph IAS, since you have to power-dive to reach the latter speed and are so G-limited by the blackout anyway at that kind of velocity....but I digress.
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BnZ, the NACA chart that the OP dismissed so readily was done with 50lb stick forces and AH matches those roll rates as I recall.
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BnZ, the NACA chart that the OP dismissed so readily was done with 50lb stick forces and AH matches those roll rates as I recall.
Understood, but go grab a 50 lbs. barbell right quick and see how many times you can curl it with your stick arm before your "control response" starts to slow down a wee bit. :D
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Is this the same Galland that asked Goering for a squadron of spitfires during BoB ?
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Yes, I have have read these comments of Galland and they were specifically regarding the Spit's carburated engine cutting out under neg Gs and the two-setting prop. Both problems were quickly corrected.
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Is this the same Galland that asked Goering for a squadron of spitfires during BoB ?
Same guy, but the "request" for a squadron of Spitfires was made in frustration and not because he really wanted Spitfires.
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Ehm?
" Spit XIV: From the Mk IX onwards, the Spitfire's roll rate became less than two-thirds of what the Mk V could achieve, and this with the SAME early peak in the speed range, that is, of around 200 MPH TAS(!). The Mk V's highest roll was about 70-78° per second at this 200 MPH TAS point. The Mk IX was 2/3rds of that according to the Supermarine's factory test pilot, so about 50° per second, getting WORSE afterwards... The Mk XIV was slightly worse than this, with the SAME early peak, as is borne out by MK XII roll data, which indicates a peak of 35-40° per second at 200MPH TAS. Outlandishly, Farnborough's well-known side-by-side tests indicate a "generally" superior roll rate for the MK XIV versus the P-51... If you search VERY long on this absolutely bizarre claim, you will find a comment saying "The MK XIV's ailerons were defective but will be fixed in production". THIS is what besting the P-51's roll rate is based on; a test pilot's wishful thinking... A major feature of most Spitfires is in fact slow ailerons, leading to the Galland comment; "great for aerobatics, but ridiculous for fighting". Clipping the wings helped moderately at low altitudes mostly, and the MK V's 78°/sec. at 200 MPH could be the top Spitfire figure if clipped, as 60-70°/sec. seemed common. This would put the MK IX peak at a 40-45°... Obviously, the NACA 868 roll chart's Spitfire figures are not valid for any mass-produced wartime Spitfires...
Another feature of all Spitfires is a slow initial turn, getting worse at high speed, because a movement of the stick top of more than 3/4 of an inch will cause it to mush forward in a controlled stall. This could be used to gain a firing lead, mind you, but at a great loss of speed or at the risk of "bending" the aircraft at high speed. Though very useful offensively, this is not really an impressive feature of the turn for escaping a pursuing ennemy, and it demonstrates a remarkably poor lift for such a large wing... The high altitude dive speed mach number is outstanding, but at low altitude it is the rigidity of the wing against buffeting, not the mach number, that makes a good diver. The Spitfire does no better than the 109's fluttering ailerons below 20 000 ft.."
Lots there, don't know where to begin, but the whole roll rate claims here remind me of Izzy.
As for the turning claim, that one leaves me puzzled as well.
And the Wing lift, well as a total the lift was quite okay;) Look at the Spits ROC for the horsepowers.
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Thanks for your responses, I am pleased to see how rational and level-headed they have been. I usually post on aircraft modeling sites (the scale plastic variety), and if these guys were here they would demand to know how many times I have flown the real thing...
I will try to clarify the points I made about the Spitfire and NACA 868 in general.
Believe me, I am the last person who would dismiss the NACA chart 868; I think this is probably one of the greatest single discovery about WWII aircraft maneuverability ever made. The 109G is sadly absent, and thus its roll rate is still a matter of debate. 109F charts do exist, and show a much higher speed for the roll peak (350 MPH TAS) than usually assumed, with peak values ranging from 85° to 109° per second. I would peg the G at 70°-80°/sec at 350 MPH, worsening to 50°/sec below 250 MPH.
Note that the Zero roll rate is labelled "stick force unknown", and that this is critical, because all Zeroes had outstanding roll up to 200 MPH, being close to 100°-120°/sec(!) at a low 120-150 MPH, this always going down after, and ever more steeply after 250 MPH TAS...
[Of note with Japanese aircrafts is that most of their speeds are quoted at Military Power, NOT War Emergency Power. In comparison, the Japanese WEP was usually longer, for instance, than the 109G's 3 minutes (I suspect the 10 WEP minutes-capable MW-50 tank of the 109 often went unused for logistical reasons...). I estimate the Ki-84 topped out at 690-700 km/h, the A6M5 at 590-600 km/h, the Tojo is quoted in a report at 640 km/h. And so on...]
Getting back to NACA 868, you will note that the Spitfire Mark is not specified on the chart, while the specific model is specified for almost all the other, conveniently obsolescent, types. This should immediately draw our undivided attention; the year of the report was 1947, and there were still MANY Spitfires in active service with many nations friendly to American interests. Moreover, in Indochina and elsewhere, many of these Spitfires were in active combat, and keeping the info blurry on these and CURRENT British aircrafts might have been seen as the polite thing to do...
As for what the NACA 868 Spitfires actually were, an indication here with these clipped MK XII tests;
http://www.spitfireperformance.com/mk12roll.gif
This from the excellent "WWII aircraft performance" site.
So the CLIPPED Mk XII ranges from 25° to 50° per second, roughly. 38°-25°/sec to right at 300-400 MPH, 50°-40°/sec to left at 300-400 MPH. The unclipped wing substracts about 6°-8°/sec. to the left at high speed and that's it. I ignored the poor performance of EN 221.
Note the unusual preference to dip the LEFT wing at higher speeds; most other aircrafts above 250 MPH have a preference to the RIGHT; but here the spiral of air spins in the OPPOSITE direction; the Griffon propeller turns the other way... Below 250 MPH, the reserve power of the engine turns UPSIDE-DOWN the preference, under acceleration, because this time the stronger TORQUE of the propeller twists opposite against a much weaker slipstream spiral. It is then that the Griffon torque wants to dip the RIGHT wing, again opposite to what most others fighters do at low speeds, and again for the same rotation direction reasons...
Some may find things to quibble, but my feeling is that the above Mk XII performance is probably slightly superior to what we can expect the real, heavier, Mk XIV to do, and is in fact more a mirror image of the MK IX... The Mk IX is slightly better than the MK XIV, if the Supermarine factory test pilot is to be believed, so my guess for the MK XIV would be a range of 40° to 20°/sec. instead of 50° to 25°/sec., from 300 to 400 MPH.
Obviously the 140°/sec of the NACA 868 chart are from another dimension; ie; fully re-designed wings of the post-war Marks...
Note that the Mk XIV was produced in fairly modest numbers, a clear sign to my eyes that it was not seen as a huge success.
Let's disgress for a moment, and consider the strange fact that a MK IX augmented to +25 lbs (colored 150 fuel) will OUT-CLIMB a MK XIV at +18 lbs, yet fails to gain 1 MPH from this extra 350 hp(!), being 40 MPH slower than the +18lbs MK XIV, despite having nearly the same power: ?!! : Radiator design, supposedly...
Does the slow roll rate mean the late Spitfires were crap? Not entirely. Take the ability to point the nose across the turn in a high speed "mushing" stall; very good offensively when the enemy numbers are dwindling, but bad defensively when they are numerous and behind you.
Much as I love the roll rate as a maneuver feature, in my game at least its importance is exaggerated. The Spitfire is probably the worst rolling pure day fighter of WWII; pilots flew around the problem quite well, and it did out-climb and out-accelerate ANYTHING, including ALL 109s... Where the Mark XIV was supreme was at high altitude, where its heavy ailerons may have lightened up and its climb rate was comparatively even more incredible. Other than this narrow high-altitude point defense role, I think it is fair to say that with its more rigid wings, the Me-109 had aged slightly better, if you discount its small, and diminishing, endurance...
Gaston.
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Let's disgress for a moment, and consider the strange fact that a MK IX augmented to +25 lbs (colored 150 fuel) will OUT-CLIMB a MK XIV at +18 lbs, yet fails to gain 1 MPH from this extra 350 hp(!), being 40 MPH slower than the +18lbs MK XIV, despite having nearly the same power: ?!! : Radiator design, supposedly...
Spitfires gained speed with 150 octane at low alt, generally 20-30 mph.
http://www.spitfireperformance.com/merlin66_18_25.jpg (http://www.spitfireperformance.com/merlin66_18_25.jpg)
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I like the part about the 190A-8 being a good stall fighter. :)
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I like the part about the 190A-8 being a good stall fighter. :)
I'm curious about that too.
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I like the part about the 190A-8 being a good stall fighter. :)
Well, all sources agree the 190 series didn't have the best rate or radius of turn.
SEEMS rather odd, but it could be argued that with the performance disadvantage German fighters tended to experience above 20K vs. the American opposition, forcing the horizontal scissoring fight might have been the best option.
Going by the wingloading and CLmax, seems like the 190 A5 ought to at least somewhat turn with the P-47 at low alt where it has a power loading advantage.
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Let's disgress for a moment, and consider the strange fact that a MK IX augmented to +25 lbs (colored 150 fuel) will OUT-CLIMB a MK XIV at +18 lbs, yet fails to gain 1 MPH from this extra 350 hp(!), being 40 MPH slower than the +18lbs MK XIV, despite having nearly the same power: ?!! : Radiator design, supposedly...
As thrila pointed out at low alts the 25lbs LFIX did gain approx 20-30mph.
However comparing a Griffon based (hi alt) XIV to a low alt Merlin 66 LFIX is absurd.
The XIV will outclimb the LFIX at high alts WITH EASE.
Horses for courses.
XIV - Hi alts.
LF IX/XVI - Low alts.
A much better comparison is the orignal Merlin 61 based F IX against the F XIV.
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Another question I'd like to know the answer to is this: Has HTC seen this data already? Or is this stuff new to them? If they have seen this data then why are there same major descepancies between AH2 aircraft models and the historical data???
If this data is new to HTC... I hope they are paying close attention. ;)
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I'm not sure about the A8 but numerous historical accounts exist of the early 190's (A3/4) just dominating the spit V's over France. The surprise was that the 190's abandoned the normal hit and run tactics and "mucked it up". While the A5 is a reasonable dogfighter when flown to its strengths I do think its raw turn capabilities are a bit under modeled. The 8K floor is correct, but what I read is a bit different. The A4 had a high speed accelerated stalled at 322 mph at high G loading. Very few pilots proved capable of catching the tip before it departed and the recovery proved very difficult. The restriction was on dogfighting below the 8k "hard deck" for that reason...
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Well for starters I have read about a clim that 109G could maintain 60 deg nose up attitude while flying otherwise horizontally level. Now if that is true what does it tell about its strengths as a turn fighter? Also interesting is J. Meimberg's story in his book about his duel with Egon Meyer how Meyer's 190 was already "hanging from its prop" and from there started a duel which took quite a while and ended in a tie. Thats probably A6 against a G2. No doubt how that kind of stall fight would end in AH.
Awhile ago I also posted link to a Russian report which claimed that the 190 would always try to turn inside LA5 and best defense would be a prolonged vertical fight to make the 190 to bleed its energy because it was a heavier aircraft.
About NACA 868 and Spitfire roll rate: If you read the document you find that the features that make a good roller are found mainly in FW190, not in Spitfire, and the chart which shows the Spitfire catching 190 in roll performance in high speed highly doubtful as in high speed the wing warping of that large wing would take care that 190 would not have to worry about Spit matching its roll, IMO that is. The newer wing was another matter which I cannot comment since I have not read about pilots experiences about those.
The internal (box?) structure of 190's wing made it torsionally very stiff and the fuselage resting on top of solid bars made the wing strong even in high speed pull-outs. The tubular spar structure of Spit is very strong (due to flexibility) in this sense too but rest of the structure does not support its torsional stiffness. I even recall a Spit veteran telling how the outer machineguns in Spit were quite useless in high speed fights as they tended to fire here and there but not the enemy in sights, again indicating that the wing indeed did warp torsionally. Of course the wing clipping was a good move as was discussed in another thread, but I don't think it could match 190 in rolling performance in any speed until the wing was completely redesigned if even after that.
After all fighter design is full of trade offs and some features can be used to counter others but no fighter holds all the cards.
-C+
PS. "seems like the 190 A5 ought to at least somewhat turn with the P-47 at low alt where it has a power loading advantage." There is also a film available of a (claimed) FW190 turning with a P47, turning inside it and even pulling lead for a shot and at the same time you can see vapour trails coming from wing tips of the P47 as it tries to turn tighter. Of course it does not tell much but, at least to me, it certainly tells me about 190's turning ability in some speed range.
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Well for starters I have read about a clim that 109G could maintain 60 deg nose up attitude while flying otherwise horizontally level.
Not too much. You fly normally with the nose pointed straight up until you run out of air if you have enough thrust to do so. Jet fighters can do this but that doesn't mean they can match a WWII prop job in turn radius.
Also, I cannot see how the 109 could have been pitched up at 60 degrees relative the Earth *and* literally flying level relative the Earth, as opposed to climbing. If that is really what is being described Wouldn't that put it well past the AoA for stall? Leading-edge slats can raise the critical AoA for a wing, but raise it to 50+ degrees???
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Of course the Spitfire IX/XIV comparison was NOT at matching altitudes; the Spit IX outclimbed the XIV at a broad band of LOW altitudes, while the Spit XIV was faster throughout but more so at high altitudes, where it outclimbed everything else, including the +25 lbs MK IX...
I was just making absolute comparisons I thought were unexpected and significant. Note that the +25 lbs (80 inches MAP) Mk IX is 20-25 MPH SLOWER than a 67 inches MAP P-51D, which has the same engine and 350 fewer hp(!), and the +25lbs MK IX was, in addition, 30 to 40 MPH SLOWER than a P-51B with 72 inches MAP(+21 lbs) and 150 fewer hp(!). Of note is that the +21lbs P-51B was no slouch climber in its own right, and was beginning to match a basic 109G-6, provided it had the -7 engine (about half the B-C production).
Of course the +25 lbs Mk IX absolutely crushes EVERYTHING in low-medium altitude climb rate, but the interesting point I wanted to make was that it apparently had little else. Perhaps the gap in speed at lower altitudes was less, but it kind of gives one pause when a fighter like the P-51 that has 350 fewer horses, with the SAME engine, and weighs thousands of pounds more, is still about 12-15 MPH FASTER at most altitudes, and about 20-25 MPH(!) faster at some of the higher altitudes...
As a comparison, the Me-109 radiator drag did not creep up with the increase in speed and power, so that when the G-14 added 300 hp, maximum speed did go up at ALL altitudes by 8MPH, and hugely so (+20-25 MPH)at low altitudes (but was rarely present, especially in later G-10s/K-4). When later G-10s and K-4s had the undernose oil cooler redesigned, this also added 8-12 MPH at ALL altitudes, and the AS/G-10/K-4 supercharger added to that another 10-12 MPH at higher altitudes.
Increases in power in the 109 led to a higher maximum speed AS WELL as more speed at lower altitudes (except in some oddball K-4 Russian tests, due perhaps to the condition of the aircraft). In the Spit IX, some of the extra power went to low altitude speed, but most of all it seemed to go mostly into its monstrous climb rate. A sort of one-trick poney that was essentially converted into a fighter-bomber with the heavier and longer-legged MK XVI.
Note that the climb rate advantage of a +25 lbs Spit IX versus a late 109 was exaggerated further by the fact that MW-50 could not be used for prolonged climbs (or dives!), the issue being I think oil circulation at sustained nose up angles. In prolonged dives, MW-50 would detonate the unloaded engine... (In any case, I think MW-50 was rare in the 109 after its few first months, because it required C-3 fuel that had to go to the 190 which could fly with nothing else.)
It is not my intention to disparage the beautiful aircraft that was the Spitfire. However, it does seem to me that despite the high speed controlled mush and its absolute climb rate superiority, advantages it retained all the way to the end of the war, the above does seem to indicate a less well rounded aircraft than usually assumed. The aging 109 definitely seemed to be holding its own better, and with infinitely fewer design changes... The only really totally obsolete feature of the late-war 109 was its endurance, and even there the Spitfire was not much better until the MK XVI was loaded down with fuel for its fighter-bomber role...
Gaston.
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:salute
I had that game back in the 80's
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Gaston,
Just to point out, every AHWiki aircraft page is headed with:
This aircraft page is in two sections:
Historical information about the {plane type} in World War II; and
Information about the {plane type} in the massively multi-player online combat simulation Aces High II.
To date, all the maneuverability information that I am aware of is contained in the AHII section of the pages. The information there is not only contexted by the AH flight model, but also by the arena format of AH itself. There are mutiple arena setups availible, but the vast majority of players congregate in the format where all planes are availible for all countries.
So the context is that in AH late war arenas you may encounter combat with any of nearly 80 plane varients modeled in the game, and performance information is colored accordingly. For instance, with the 109G, depending on which varient, loadout options, and gross weight, the Cv for clean configuration could be anywhere between 230 mph, to 250ish mph. Anywhere above Cv, the planes best rate of turn is on a decending trend, and being limited by the pilots G tolerence. So the games flight model itself gives the best turn performance below 250, but in the gameplay environment a typical AH player will be using it in, any 109G has a number of planes to contend with that will out class it in rate and radius of turn. When you place it in that context, it makes sense to advise to keep it between the top end of corner velocity, and VNE, so that the option to disengage is there when facing a more nimble plane it would never have historically faced.
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I understand what you are saying, the CV means that past a certain velocity, the increasing turn rate shifts to an always descending trend.
I think this concept is inherited from jet air combat, where "energy" has a great role to play, because the range of speeds is so vast compared to WWII. The "CV"; the speed at which the turn rate "peaks", is always very low compared a jet's maximum speed, so it is crucial to adjust CORRECTLY between that and the top speed to get where you want to go; thus the slowing "high yo-yo" versus the accelerating "low yo-yo"; terms and maneuvers I have never heard from WWII pilots accounts, which are absolutely bread-and-butter to jet fighter pilots...
When you listen to WWII accounts, the "energy" (which I read as "excess relative speed") counts less than the altitude advantage and acceleration. Also the CV "peak" was not linear, limited to one, or similar in shape among these vastly idiosyncratic aircrafts. The Me-109G had two CV "peaks", with a big hole in the middle, the P-47 and P-51 had very late CV "peaks", which meant their best turn rates could not be sustained without making a descending spiral, because the engine had no reserve power at this best turn rate, so close was this to the maximum level speed.
With altitude, a WWII fighter could make a high speed attack/getaway (boom and zoom), but an overlooked aspect of this "energy fighting" is the exaggerated effectiveness of the gun armament in computer games; in reality, the higher the relative speed, the weaker the armamament strike. The more energy you have compared to your opponent, the more bullets/shells will miss. In WWII they HAD to stay and maneuver to finish the job, and they could not attack at too high a relative speed. This is why the Me-163B was so hopeless, despite an armament that could crush any foe. This was simply not how guns allowed the game to be played...
The exception to the above was combat against Japanese aircrafts, where a few hits would ignite the large long range unprotected fuel tanks of the Japanese, and where the higher speed actually minimized the maneuverability disparity between Japanese and American aircrafts. Here is a WWII situation where excess relative speed was actually useful...
In Europe there were more maneuvering contests. The Germans faced a disadvantage due to the low fuel situation; no permanent Combat Air Patrols (CAP) were possible; fights were entered after a long climb with a hot engine. This probably lost them the acceleration parity they had a higher altitudes, making it impossible for them to avoid the descending spiral or dives that so favored the P-51 and P-47's best turn rate. A turn rate peak (CV) which, without altitude loss, could not be sustained, so near was it to the maximum level speed of these two American fighters...
To summarize, my point is that during WWII, the weakness and range of the gun armament did not allow "energy fighting" to the extent of applying the later principles of jet air combat, and the "corner velocity" principle is too neat and simple for the bunch of prop-driven weirdos that are supposed to fit into it.
Gaston.
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PS. "seems like the 190 A5 ought to at least somewhat turn with the P-47 at low alt where it has a power loading advantage." There is also a film available of a (claimed) FW190 turning with a P47, turning inside it and even pulling lead for a shot and at the same time you can see vapour trails coming from wing tips of the P47 as it tries to turn tighter. Of course it does not tell much but, at least to me, it certainly tells me about 190's turning ability in some speed range.
Here it is:
http://www.youtube.com/watch?v=Xqjs5NzKSxg
190A-8 vs La-5 timecode 4:52
190A-7 vs P-47 timecode 6:08
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Hello everyone, I'm Gaston Marty, the designer of an extensive re-vamp of the old Avalon Hill "Air Force" boardgame. It is called "Advanced Air Force", and you can see and print it for free at "Mike's Air Force Dauntless web site";
Gaston.
<sniffle> fond memories of having no one to play Air Force or Dauntless with way back when. It was my first exposure to a ww2 aircraft game, building on the interest I was developing at that age. I think I might even still have the data cards somewhere.
4SLL (pp) -.6
:noid
<edit> after browsing the replies, it seems I'm the only one who actually played these games, lol.
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<edit> after browsing the replies, it seems I'm the only one who actually played these games, lol.
No, you're not alone...
(http://img169.imageshack.us/img169/966/p1010478mk1.jpg)
You can see, I still have them. They are waiting for the day I find someone to play with ;)
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Even cursory review of contemporary from the period will show that "boom and zoom" was copiously practiced whenever circumstances allowed in all areas of operation.
Furthermore, even a cursory review of the available gun camera footage and contemporary reports will reveal plenty of cases where a single pass and a single burst resulted in either severe damage or destruction of the enemy aircraft. I have never seen any evidence that the guns lethality in AHII is greatly out of whack, especially when you consider that he average AH pilot has the advantage of dozens/hundreds/or even thousands of hours of gunnery practice under realistic conditions, unlike his real life contemporary.
Finally, while the specific terminology of "energy fighting" was not invented yet, pilots were taught about converting airspeed to altitude and vis versa, and taught almost the entire range of vertical maneuvers still in use today. There are plenty of examples from contemporary sources of the use of 3 dimensional/vertical/energy maneuvering in WWII....Hell, Max Immelman probably "invented" the concept in WWI!
I understand what you are saying, the CV means that past a certain velocity, the increasing turn rate shifts to an always descending trend.
I think this concept is inherited from jet air combat, where "energy" has a great role to play, because the range of speeds is so vast compared to WWII. The "CV"; the speed at which the turn rate "peaks", is always very low compared a jet's maximum speed, so it is crucial to adjust CORRECTLY between that and the top speed to get where you want to go; thus the slowing "high yo-yo" versus the accelerating "low yo-yo"; terms and maneuvers I have never heard from WWII pilots accounts, which are absolutely bread-and-butter to jet fighter pilots...
When you listen to WWII accounts, the "energy" (which I read as "excess relative speed") counts less than the altitude advantage and acceleration. Also the CV "peak" was not linear, limited to one, or similar in shape among these vastly idiosyncratic aircrafts. The Me-109G had two CV "peaks", with a big hole in the middle, the P-47 and P-51 had very late CV "peaks", which meant their best turn rates could not be sustained without making a descending spiral, because the engine had no reserve power at this best turn rate, so close was this to the maximum level speed.
With altitude, a WWII fighter could make a high speed attack/getaway (boom and zoom), but an overlooked aspect of this "energy fighting" is the exaggerated effectiveness of the gun armament in computer games; in reality, the higher the relative speed, the weaker the armamament strike. The more energy you have compared to your opponent, the more bullets/shells will miss. In WWII they HAD to stay and maneuver to finish the job, and they could not attack at too high a relative speed. This is why the Me-163B was so hopeless, despite an armament that could crush any foe. This was simply not how guns allowed the game to be played...
The exception to the above was combat against Japanese aircrafts, where a few hits would ignite the large long range unprotected fuel tanks of the Japanese, and where the higher speed actually minimized the maneuverability disparity between Japanese and American aircrafts. Here is a WWII situation where excess relative speed was actually useful...
In Europe there were more maneuvering contests. The Germans faced a disadvantage due to the low fuel situation; no permanent Combat Air Patrols (CAP) were possible; fights were entered after a long climb with a hot engine. This probably lost them the acceleration parity they had a higher altitudes, making it impossible for them to avoid the descending spiral or dives that so favored the P-51 and P-47's best turn rate. A turn rate peak (CV) which, without altitude loss, could not be sustained, so near was it to the maximum level speed of these two American fighters...
To summarize, my point is that during WWII, the weakness and range of the gun armament did not allow "energy fighting" to the extent of applying the later principles of jet air combat, and the "corner velocity" principle is too neat and simple for the bunch of prop-driven weirdos that are supposed to fit into it.
Gaston.
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And Boelcke. His Dicta Boelcke is still used in fighter pilot training today.
http://en.wikipedia.org/wiki/Dicta_Boelcke
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<sniffle> fond memories of having no one to play Air Force or Dauntless with way back when. It was my first exposure to a ww2 aircraft game, building on the interest I was developing at that age. I think I might even still have the data cards somewhere.
4SLL (pp) -.6
:noid
<edit> after browsing the replies, it seems I'm the only one who actually played these games, lol.
My brother was an Air Force/Dauntless fanatic. Still has the boxes in a...um...safe place. Oddly enough was just emailing him yesterday about addons for the games.
If you're seriously into playing, let me know - -I can see if he's up for some PBEM!
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No, you're not alone...
(http://img169.imageshack.us/img169/966/p1010478mk1.jpg)
You can see, I still have them. They are waiting for the day I find someone to play with ;)
I still have Luftwaffe, in the basement. Tried playing that solo several times, but not a great solo game. Also played a lot of Richtofen's War - and found one of my all time "I must be getting old" moments on a visit to Smithsonian Air and Space Museum, where they had a copy of the game on display outside the WW1 hall.
Personally liked Panzer Blitz/Panzer Leader about best from that era. Still have those, plus Tobruk and a few others, in the basement stack.
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To answer Bnz's comments;
I did not intend to mean that energy fighting was useless, not used, or unknown in WWII. What I meant is that it was not as dominant a tactic in WWII Europe as usually assumed, and that contrary to widespread assumptions, maneuvering combat was a lot more prevalent in Europe than in the Pacific. This was due to the relative equality of characteristics between the opponents in Europe, and was noted as such by actual pilots of the time. In the Pacific, the Japanese noted ONLY the Hellcat would engage them regularly in maneuvering combat, and it has, by the way, by far the highest tally of kills... In theory the P-38 could also maneuver, but I think in person the P-38 is a blinder and more intimidating ride than "on paper"...
Note that I do concede energy tactics were more predominant in the Pacific, but I think it is useful to emphasize that this importance was due in large parts to the characteristics of the opposing aircrafts involved.
Note the premium I put on the altitude advantage, which is in part related to energy tactics, but the most important, and overlooked, thing about altitude advantage is that, when you are not lined up behind another aircraft, which is most of the time, pointing your nose at or in front of him means he is slipping away, because his progress will be faster than yours, since you are at a cross angle to his trajectory. Even if your aircraft is faster and more maneuverable, allowing you to keep the lead ahead, your inputs will not match exactly enough his rate of progress to put most of your shots into him.
By being above him and nosing down, the dive acceleration allows you to match his rate of progress easier, making for a steadier aim from a wider variety of angles. So altitude advantage gives you a better, steadier aim, and, I would argue, that this is at least as important as the overtaking speed to obtain the single-burst kill you were talking about.
I attempted to duplicate this in my game by allowing a greater vertical gun reach from above; 1200ft., vs 600 ft. from below.
The way I see it, pure Boom and Zoom was essential against a more maneuverable enemy that was not slower; early Pacific. Very good against an unusually fragile enemy that was slower; late Pacific, and useable against an enemy that started or stayed below you, PROVIDED you had good high speed handling on your side; P-47, P-51; late Western Europe. The P-38 could Boom and Zoom at LOW altitudes against the slower Japanese, where its poor allowable TAS was much higher, but did badly against the faster or higher Germans. The FW-190A and A6M Zero are two types that generally would do poorly with Boom and Zoom tactics. The Me-109G, on the other hand, would do well if the pilot remembers the big trim wheel (Not always the case!)...
As for jet-era vs prop-era tactics;
A high yo-yo to slow you down to a better turn rate would be of no use in a P-51 or P-47, which turn better at higher speeds...
A low yo-yo to accelerate in a turn would probably make more sense in many American prop fighters, but not if you are flying a FW-190A, A6M Zero, or any other kind of WWII fighter that mushes at higher speeds (FW-190A), or that doubles its turn radius quickly as speed goes up (A6M, FW-190A or medium speed Me-109G). It is a valid tactic in some circumstances, but at the serious cost of having to raise the nose afterwards to hit your opponent, and I think it would have been done often simply to stay in the enemy's blind spot...
WWII fighters had such diverse personalities that cookie-cutter energy maneuvers like high/low yo-yos were not necessarily applicable.
Another general concept like Corner Velocity simply has no practical value for numerous types; Me-109G, P-47, P-51...
Jets have far more consistent traits (and on top of that behave symmetrically!), so I would underline instead the specialized WWII knowledge that was necessary to achieve dozens or hundreds of kills, and encourage to not try to placate post war jet fighter training on that era.
I would say a few things would stand out to simmers who would fly these WWII contraptions for real; the confusion and near-physical pain created by the tremendous engine noise, the vibrations and crummy static-ladden radio (not so on spark plug-free jets!), all of which means it takes a while to see calmly past the windows...; the difficulty of seeing down and ahead; and perhaps most of all the shocking weakness of the guns, due in large parts to the various buffeting oscillations of a small maneuvering aircraft.
The effect of guns would be hard to replicate exactly by a computer model, but I will take as an example a recent poster in this forum who had great success with the Me-163B, shooting down regularly several bombers, to a maximum of four. In reply, someone said that the Me-163B had trouble getting to the bombers, but once there it had no trouble shooting them down. In fact, it is just the opposite; the guns were the single biggest headache of the Me-163B, despite 30mm ballistic properties that were not all that bad, as recently shown here in an animation (or is it in Il-2 GD?).
That someone in real-life shot down 2 B-17s with the Komet is probably a minor miracle, and was seen as such at the time. I think most discrepancies with real-life successes in simulations boils down to the gun impact on actual structures and the real flight buffeting accuracy, but solving these problems is not an enviable task...
I hope I'm not boring everyone to death, so I'll conclude quickly by saying to Lusche, Shane, or anyone, that if they want to play by E-Mail my version of the Air Force game, available for free as "Advanced Air Force", I am perfectly willing: Here again the link;
http://www.visi.com/~mrowles/Mike%27s_Air_Force_page.html
My E-mail; Gaston1_01@hotmail.com
For me too, the recurring problem is to find someone who likes to play this game. Note that my "Advanced" variant requires having the original game rules, preferrably Avalon Hill, and the maps and counters.
Good luck to all simmers, whether on screens or cardboard!
Gaston.
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Oh, believe it when I say you are not boring any of the likes of us. You have a great many tuned in to the info you have provided. Each new post you make lends to a wealth of information that you have to share. All of it, I hope can be proven (or disporven) and taken seriously by HTC because if what you're saying (and showing) is true then a number of aircraft models in AH2 need to be adjusted accordingly.
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To answer Bnz's comments;
I did not intend to mean that energy fighting was useless, not used, or unknown in WWII. What I meant is that it was not as dominant a tactic in WWII Europe as usually assumed, and that contrary to widespread assumptions, maneuvering combat was a lot more prevalent in Europe than in the Pacific.
The most common kind of "tactic" described in accounts is flying up behind the poor SOB and blasting him before he knew what hit him. Speed, translating into the ability to close the distance quickly before being spotted, obviously facilitates this.. Whether you want to call it boom and zoom or whatever is up to you. Personally, I think "one pass, haul a**" is more descriptive of most kills I've read about. :) I agree that it does stand to reason that pilots in Europe did not shun turning dogfights to the extent American pilots in the Pacific did, simply because the airplanes were more evenly matched in that regard.
For that matter, most "energy fighting" in the game will actually be finished by some "turn fighting" after the E fighting has given an initial advantaged position.
The FW-190A and A6M Zero are two types that generally would do poorly with Boom and Zoom tactics.
If the 190A was no better than the Zero at high speed this is the first I'm hearing of it.
Here is what Eric Brown has to say:
"The elevators proved to be moderately heavy at all speeds, particularly at above 350mph (565km/h), when they became heavy enough to impose a tactical restriction with regard to pullout from low-level dives."
Moderately heavy is distinct from being locked up. "with regard to pull out from low level dives" indicates enough elevator authority is retained to influence the course of the machine even at high IAS, provided you have the room to pull out. 350 mph is a high IAS, more than enough to inflict all the Gs the pilot can stand in the Fw-190. Above 20K, 350mph is well over 420mph.
Here is what a Navy document describing tests of a captured 190-A5 have to say:
"In general, stability and controllability of the Fw-190 in dives were satisfactory. However, at speeds above 350 knots indicated vibrations were felt and control forces became noticeable. In no case did control forces become objectionable. Diving restrictions indicated by a captured document, and as posted on the airspeed indicator in the captured airplane, were as follows:
466 mph (ind) below 10,000 feet
426 mph (ind) 10,000 feet to 16,500 feet
360 mph (ind) 16,500 to 25,000 feet"
I'd say an airplane which can be taken to 450mph TAS or more safely can be slightly useful for bnz tactics. ;)
Later, under control forces
"Control forces in the Fw-190 were generally extremely light....Control forces become noticeable, but not objectionable, at high speeds."
For comparison, look up some of the reports on the control forces in the P-51. It would seem the Fw-190's handling in a high-speed dive was fairly competitive for its time.
As I said in an earlier post, one could perhaps argue that control forces at high speed are a little under-modeled in AHII. Or that our "pilot" simply seems inordinately strong. ;) But that phenomenon seems to be consistently true across the board and not to be a problem with any specific plane in AHII.
A high yo-yo to slow you down to a better turn rate would be of no use in a P-51 or P-47, which turn better at higher speeds...
The primary purpose of a high yo-yo is not to slow down. That can be done through throttle management, a high-G barrel roll, deployment of drag devices, etc, and doing this while staying "saddled up" is indeed the simplest solution if one can match the bandit in front of you turn-for-turn at low speed. The primary purpose of a high yo-yo is to avoid overshooting and stay more or less in the rear quarter of a slower bandit while maintaining enough total energy that your plane can still maneuver tolerably well for a shot. As such, it can be a useful maneuver for both planes against adversaries that turn better at low speeds. Albeit, I realize at typical MA alts both planes are at a thrust ratio disadvantage against many types, thus limiting how long they can maintain superiority in vertical maneuvering before energy levels even out. This of course becomes less true at more realistic altitudes.
I don't know what you mean by "higher speeds", a P-51/47 turn with a reasonably high rate between 220-300 mph, any faster than that you are G-limited and easily dodged by a slower opponent at a more optimal maneuvering speed for a typical prop fighter. IIRC correctly, the structural maneuvering limit for the P-51 was 8gs/270mph IAS.
Another general concept like Corner Velocity simply has no practical value for numerous types; Me-109G, P-47, P-51...
Care to explain yourself here? Alot of us find the concept of corner velocity very useful, in the general sense of knowing the range where we have enough speed to turn at a decent rate without having excess speed, and also in the general sense of knowing that if we can convince our opponent to bleed his own airspeed well below corner he may become an easy target, even for a far less "maneuverable" aircraft.
and perhaps most of all the shocking weakness of the guns, due in large parts to the various buffeting oscillations of a small maneuvering aircraft.
As I alluded to earlier, the guns seem to have splashed many an enemy fighter before he knew what hit him. I mean, single rounds of .50 cal are used to disable vehicle engines at thousands of yards to this very day, and many armaments from WWII dwarf .50s. From what I've seen of gun camera footage, even concentrated .303 fire seems to have been quite nasty, provided the shooter was *close* and *on target*, to say nothing of HMG or cannon. It is no wonder that AHII players are lethal with all the practice they get. On the other side of the fence, we get posts from noobs regularly lamenting the impotence of one gun package or the other...presumably their inexperience puts them in the same boat as the average recruit in WWII.
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Gaston wrote;
When you listen to WWII accounts, the "energy" (which I read as "excess relative speed") counts less than the altitude advantage and acceleration. Also the CV "peak" was not linear, limited to one, or similar in shape among these vastly idiosyncratic aircrafts. The Me-109G had two CV "peaks", with a big hole in the middle, the P-47 and P-51 had very late CV "peaks", which meant their best turn rates could not be sustained without making a descending spiral, because the engine had no reserve power at this best turn rate, so close was this to the maximum level speed.
Gaston please do a little research on the definition of Conner Velocity.
Just a few notes, no fighter in WWII had a Cv that could be maintained. All fighters had to descend in a spiral to maintain Cv.
The definition of Cv is the lowest speed at which you can pull max G. Traditionally Max G is airframe limited.
So your statement of 2 peak Cv of the 109 is sort of meaningless because by definition LOWEST means 1.
"energy" (which I read as "excess relative speed")
Energy is and always will be defined as Speed ^ 2 + Altitude.
Simply put you can convert speed to Altitude and Altitude to Speed. The total energy does not change when you do this conversion, with the exception of inefficiencies such as drag.
HiTech
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This is the velocity versus G diagram for the P-51D from T.O. No. 1F-51D-1:
(http://img3.imageshack.us/img3/8854/p51dvgyu5.jpg)
I don't see any evidence of peculiar bumps.
There is a clearly defined corner velocity which is the intersection of the lift-limit curve and the structural limit.
Contrary to the claim made here, I find that jet fighters have far more variations from the ideal norm than WW2 prop fighters due to their higher wing loadings and higher speeds: their lift curves are warped to some degree by compressibility as their corner velocities tend to approach transonic speeds.
So they don't quite follow the ideal curves where the lift limited value for n increases directly with the square of velocity.
For comparison, here is a v-n diagram for the F-4 Phantom at various angles-of-attack:
(http://img167.imageshack.us/img167/8985/vnm05dd6.jpg)
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I will try to answer the points of Bnz and Hitech more or less in order.
- "No WWII aircraft could maintain CV; they all had to spiral downward". The primary maneuver recommended by Steinhoff in combat with the Me-109G against the P-51 and P-47 was the CLIMBING spiral. This was THE major advantage of the 109G over almost all foes. Steinhoff went on to point out the P-38 was a particularly dangerous foe because it was the only (American?) aircraft capable of matching or exceeding the 109's spiral climb. (Borne out by the P-38's climb rate if not its kill ratio!) Not a maximum rate turn, I know, but from lower speeds the acceleration was there...
- "I have never heard the FW-190 was no better than the Zero at high speeds." They were equally bad but in different ways at DIFFERENT speeds.
Eric Brown's phrase "tactical restriction in pull-out from low-level dives" sounds mild and understated, but the story from NUMEROUS U.S. pilots sounds like this; "They could dive, but if by 8000 ft. they were not starting to pull out, you knew they were not going to make it." or "I've seen numerous times the 190s pilots try, try, try to pull-up and then just watched them pankake themselves." or " The 190s went out of control at low altitude, by contrast I've never seen a 109 go out of control like that and hit the ground."
I think many have been mislead by the notion of very light elevators, which the FW-190 DID have. Lightness of control does not necessarily translate into a trajectory change. The Zero had immensely heavy controls at much lower dive speeds, and thus nose dived into the sea with inexperienced Kamikaze pilots. It probably WAS more survivable to pankake than nose dive, and the speeds that did this to the Zero were MUCH lower than those that doomed the 190, but the difference is definitely not great. 8000 ft. for a pull-out means a very poor high speed maneuverability.
A bit of trivia; above 500-550 MPH TAS only the 190's nose mgs could be safely fired...
This confusion about "light" controls led me to break-down elevator response into three parts to try to get the "feel" right for my boardgame.
I simplified maneuverability issues into two categories; Roll rate on one side, and pitch/turning on the other.
Roll rate is in my opinion fairly straightforward, and is very well covered in my view by a roll rate chart, with only the low speed engine torque and the high speed, always opposite, air spiral to muck things up. On some types, the drifting of the nose to one side will require the pilot to use the rudder to keep the nose straight; LEFT rudder(All Me-109s, and at an increasingly heavy left footload with speed! At lower speeds (below 250 TAS) it shifts to the opposite for the 109; right rudder under acceleration, or climb.) or RIGHT rudder (A6M Zero, similar amplitude as the Me-109, but a very light right pedal for the luckier pilot!). This constant offset rudder position slows the roll to the side applied, increasingly so with speed, making the aircraft a less and less symmetrical roller as speed increases above 300 MPH TAS.
Pitch/turning/loops etc... is a massively more difficult thing to figure out, as much of the data is only partial; I broke it down like this;
1-Pilot authority over elevators; FW-190A has that in spades. A6M Zero bows out early at med-high speeds(300-370 MPH)... P-51B/D is heavy, with difficulty at high speeds (420 MPH+). Spitfire excellent. P-47D excellent. Me-109G very heavy, but with unexpected increased performance at the end, if the pilot did not wait until the trim wheel was too hard... P-38 excellent, enhanced by twin handhold.
2-Elevator control surface authority over aircraft attitude (which I define as the initial turn-in); FW-190 excellent, P-51 poor at low speeds, growing rapidly to excellent, Spitfire average, worsening to poor, Zero outstanding, P-47D poor at low speeds, growing to average, Me-109G very good. P-38 average, growing to outstanding. Further up, the P-38 blows out in a big way if the extremely severe, low mach 0.67 limit is exceeded.
3-Aircraft pitch attitude authority over aircraft trajectory; FW-190 blows out in a big way, mildly at 300 MPH TAS, badly at 400 MPH TAS, Spitfire mushing worsening above 300 MPH TAS, but from such a good start that the turn rate is still good (650 ft. radius for a MK XIV at 400 MPH TAS!). Above 450 MPH TAS, a new limiting factor appear because of the feather light elevators; an unnatural, very light touch is required to avoid bending the wings... Me-109G starts very well but bows out abruptly at medium speeds only to make a huge come back at 400-420 MPH, IF the pilot thought of lightening his heavy load with the trim wheel... The P-47 bows out from the very start, mushing throughout the speed range in turns, but improving with speed, especially with the wings level, to the point of excellence for loops and pull-outs at dive speeds. The P-51D starts poorly but becomes extremely crisp, probably the absolute best, with an incredible turning radius of 450 ft. at 400 MPH TAS(!), which could probably be approached at even higher speeds, if the wartime fabric elevators did not waste the pilot's strenght. An aging Saburo Sakai flew a P-51D long after the war, and he enthused about the tight turns he could make at 500 MPH TAS(!). Metal P-51D elevators had appeared just as the war ended, too late to prevent the P-38 from beating the P-51D by a wide margin above 400 MPH, where it would also beat by a smaller margin the closely matched P-47D and Me-109G also.
The Hellcat, Corsair and many others I do not know in detail.
-"Cornering Velocity has no practical value"; I meant it has value for determining the peak rate of turn of the ennemy, but in the case of SOME WWII aircrafts, the tightest radius of turn is near 400 MPH! The Me-109G can be trimmed tail-heavy to have two peak turn rates, and though I don't know the exact figures, I don't think its 420-480 MPH turn rate is hugely wider than its 200-250 MPH turn rate. If the Mustang can turn like a Zero at 400 MPH TAS(!), then be beaten by a tail-heavy 109G at 420 MPH, surely the 109's 420 MPH turn can't be much wider than it's own first peak, or then the first peak would be Zero-like at Zero speeds; unlikely.
Very interesting on this issue was an EXTENSIVE series of flying mock combat tests flown for historical research in.... the 1990s!
Thanks to these tests I figured out the high speed air spiral as being opposite to the torque.
They found, to their surprise, that the P-51D and P-47D peak turn rate was at about 400 MPH TAS; close to the maximum speed, and that for the P-51D the stall was surprisingly harsh much below that peak turn rate, to the point they found it unsuitable for much maneuvering combat at low-medium speeds. Surprised to hear this, one well-known P-51 ace commented that maybe in their day they could sense the stall better and fly closer to it. I think somewhere in between is likely. Memories are often embellished...
I disagree the maximum rate of turn on WWII aircrafts is airframe limited. Oleg Maddox pointed out, correctly in my view, that these small WWII fighters were near-impossible to break in level turns or in any maneuver below dive speed. They would break during dive pull-outs, but NOT from level speed turns. The P-51 was rated for 12G, the Me-109 for 15. I don't know how many Gs pilots could take, 6 or 7, but it was said veterans often died in combat after a long vacation; they didn't recover quickly enough from G-induced blackouts...
Finally for the armament effects, the Luftwaffe during the war came out with a well-known statistic; 1% of fired shells in combat would find the target, and a B-17G required 20 X 20mm shells to be brought down. The FW-190A-6 of the time carried 780 20mm shells, which gave about 8-9 rounds on target; at least the entire ammo of TWO or THREE FW-190 was the MINIMUM required... Though occasionally a well-centered burst will light-up an aircraft, remember that in all likelyhood the more boring gun camera footage will be less well-known...
I remember I thought the Luftwaffe overstated their case, but still...
I hope I did not forget too many points.
Gaston.
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Gaston:
"Some may find things to quibble, but my feeling is that the above Mk XII performance is probably slightly superior to what we can expect the real, heavier, Mk XIV to do, and is in fact more a mirror image of the MK IX... The Mk IX is slightly better than the MK XIV, if the Supermarine factory test pilot is to be believed, so my guess for the MK XIV would be a range of 40° to 20°/sec. instead of 50° to 25°/sec., from 300 to 400 MPH."
The XIV has the same wing as the VIII AFAIK. The ailerons had been modified for better performance. (Hinge issue), and AFAIK the wing was stiffer.
"Note that the Mk XIV was produced in fairly modest numbers, a clear sign to my eyes that it was not seen as a huge success."
To the eyes of Jeff Quill, one of Supermarine's chief test pilots, the XIV was a quantum leap, no less.
The numbers indicate more of that WW2 was coming to an end, as well as there were many more Griffon variants.
When Hawker was introducing the Typhoon, there was some speculation if the Spitfire would be phased out due to insufficient top speed. But the Griffon cured that, and the Mk XII proved to be faster than the Typhoon.
"Let's disgress for a moment, and consider the strange fact that a MK IX augmented to +25 lbs (colored 150 fuel) will OUT-CLIMB a MK XIV at +18 lbs, yet fails to gain 1 MPH from this extra 350 hp(!), being 40 MPH slower than the +18lbs MK XIV, despite having nearly the same power: ?!! : Radiator design, supposedly..."
Apples and oranges. It will have the same clock to 20K...maybe. (5 minutes).
Now, the prop is quite different BTW.
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Gaston,
The Spitfire Mk IX at +25lbs boost is significantly faster than the Spitfire Mk IX at +18lbs boost, just as the Spitfire Mk XIV is faster at +21lbs boost than at +18lbs boost.
I don't know where you are getting claims that the +25lbs boost made no difference in the Mk IX's speed.
Mind you, that Mk IX at +25lbs boost was still a bit slower than the Mk XIV at +18lbs boost.
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- "No WWII aircraft could maintain CV; they all had to spiral downward". The primary maneuver recommended by Steinhoff in combat with the Me-109G against the P-51 and P-47 was the CLIMBING spiral. This was THE major advantage of the 109G over almost all foes. Steinhoff went on to point out the P-38 was a particularly dangerous foe because it was the only (American?) aircraft capable of matching or exceeding the 109's spiral climb. (Borne out by the P-38's climb rate if not its kill ratio!) Not a maximum rate turn, I know, but from lower speeds the acceleration was there...
Gaston when you wish to learn and expand your knowledge, let me know, because your response to my statement "No WWII aircraft could maintain CV; they all had to spiral downward".
Has absolutely nothing to do as to why a climbing spiral is a good idea in a 109.
Your statement that any plane in WWII had its tightest turn radius at speeds about 400 mph is just simply insane, and shows a complete lack of any understanding of the theory of flight, and hence what ACM is all about..
So as long as you wish to state facts that have nothing to do with a discussion I am finished with this thread. You can try baffle the clueless with useless information, but many people here see the truth behind the BS.
P.S. Would you happen to know a man named crumpp?
HiTech
HiTech
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Gaston:
Unlike many who post here, I'm not an aeronautic engineer, math guru, or trained pilot. However, even as an "Aircraft and Vehicles Forum" amateur some of what you're saying doesn't make any sense.
E/M curves, baby.
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P.S. Would you happen to know a man named crumpp?
HiTech
HiTech
Ya beat me to it, HT! :rofl :rofl :aok
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Gaston when you wish to learn and expand your knowledge, let me know, because your response to my statement "No WWII aircraft could maintain CV; they all had to spiral downward".
Has absolutely nothing to do as to why a climbing spiral is a good idea in a 109.
Your statement that any plane in WWII had its tightest turn radius at speeds about 400 mph is just simply insane, and shows a complete lack of any understanding of the theory of flight, and hence what ACM is all about..
So as long as you wish to state facts that have nothing to do with a discussion I am finished with this thread. You can try baffle the clueless with useless information, but many people here see the truth behind the BS.
P.S. Would you happen to know a man named crumpp?
HiTech
HiTech
Boom roast it
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I disagree the maximum rate of turn on WWII aircrafts is airframe limited.
What's relevant to the discussion is that it is G limited.
I think this concept is inherited from jet air combat, where "energy" has a great role to play,
This is backwards. E-M plots exist from early war, which were of course classified information at the time. The concepts were a little more widely disseminated and somewhat tweaked during the jet age.
-"Cornering Velocity has no practical value"; I meant it has value for determining the peak rate of turn of the ennemy, but in the case of SOME WWII aircrafts, the tightest radius of turn is near 400 MPH! The Me-109G can be trimmed tail-heavy to have two peak turn rates, and though I don't know the exact figures, I don't think its 420-480 MPH turn rate is hugely wider than its 200-250 MPH turn rate. If the Mustang can turn like a Zero at 400 MPH TAS(!), then be beaten by a tail-heavy 109G at 420 MPH, surely the 109's 420 MPH turn can't be much wider than it's own first peak, or then the first peak would be Zero-like at Zero speeds; unlikely.
Maximum rate of turn or Cv is going to be where the stall and G limits are both met simultaneously.
And here is a plot from 1940. The top is clipped, but it is clear that the peak (Cv) is Below 250 CAS. On the left line is the stall limit, on the right line is the G limit. Time to turn 360 can be read on the right. Radius is marked with the dotted lines.
(http://www.badz.pwp.blueyonder.co.uk/images/Sust2.jpg)
But for even better clearity. Badboy took the Spit E-M diagram from the same document, and produced one for the Spit1 under the AH flight model.
(http://www.badz.pwp.blueyonder.co.uk/Files/Images/Spit1b.jpg)
But let's compare that with the diagram for the real Spitfire MkI.
(http://www.badz.pwp.blueyonder.co.uk/Files/Images/Spit1a.jpg)
Here we can see that both the real Spitfire and the AH Spitfire have the same corner velocity at that altitude and configuration, so let's compare a turn. Just for example I've selected a 5g turn at the corner speed of 250mph. I've indicated on the diagram for the real Spitfire that it would need to descend at 16 degrees below the horizon to sustain that turn and it would turn a full circle in about 14.5 seconds with a radius of about 850ft. You can see from the diagram for the AH Spitfire that it would also make the same turn in about 14.5 seconds with a radius of 850ft, and that it would need to descend at an angle of 23 degrees below the horizon, a descending turn only 6 degrees steeper than the real aircraft. But the turn rates and radii for the turn, along with the corner speed are amazingly close. The difference in the angle of descent is probably due to differences in engine power available at that altitude between the real world tests and Aces High, and perhaps some differences in weight.
It is interesting that both diagrams are essentially the same shape, and that they agree quite closely in many respects, indicating that the flight model in Aces High has accounted for all of the aerodynamic factors that would influence the shape of the curves to any significant degree. A worthy achievement indeed. Kudos to HTC.
This is even more significant, because I've made a similar comparison with the Spitfire and 109e from other simulations, and so far Aces High has first place for accuracy. I'm just thinking of writing up the whole comparison for an article on SimHQ.
Merry Christmas guys...
Badboy
You seem to have latched on to odds and ends of details, but are not putting them in the correct context or even within the flight envelope. With that first image for the 109E we can follow the 6G line through various speeds and see that the turn radius and turn rate do not "re-peak" in some way. Even with a mechanical control peculiarity specific to an aircraft model that limitation is going to take place inside the stall limit and G limit (within the flight envelope).
Maybe that will help.
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blah blah blah... we're talking about a 2d board game (fun as hell).. after going to the site, I eventually discovered Mr. Martin's "Advanced Air Force" page and examples of new data cards.
I like the game and see where he's going with this technical blahdebalh (I just fly either game and shoot stuff down :noid ). My only "meh" is the data cards... for some reason I find the arch format hard to read at a glance. I like the old grid style.
I agree the cards need to be a bit bigger for the data. The color is cool, keep that, but more $$. I think you could benefit from editing some of the data presented. You also might want to spiff up the bomber cards with colors and field of fire arcs like the old data cards did.
Are you working on a rule book too? Or are your efforts contained within the data cards utilizing existing rules? Another question I have is the planeset. Air Force and Dauntless, both with expansion packs, iirc, covered just about everything, lol. Not to mention various ship classes, ground targets, AA, etc... (I was planning to buy little miniture planes to use instead of the little printed cutouts - never got around to it.) Are you updating them all or just a certain planest, ala Aces High?
You may now return to your technical blahdeblah. :cool:
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I don't know if I'm one of the clueless, but I found this thread to be very interesting. I actually read through all four pages, word for word. So, even if I'm overly gullible, thanks Gaston.
"...but an overlooked aspect of this "energy fighting" is the exaggerated effectiveness of the gun armament in computer games; in reality, the higher the relative speed, the weaker the armamament strike. The more energy you have compared to your opponent, the more bullets/shells will miss. In WWII they HAD to stay and maneuver to finish the job, and they could not attack at too high a relative speed."
This, however, doesnt make much sense to me. Like many others here, Im far from an aeronautical engineer - Im a finance guy. I just love war birds and AH gives me the chance to get about as close as I ever will to driving one.
I do agree with Hitech that "energy" is a clearly defined term and you seem to be using it incorrectly... but, that said, and especially in the case of the effectiveness of non-incendiary, non-explosive ammunition, I don't understand the math behind the statement that a higher relative speed results in a decreased armament impact value.
While I'll buy that higher speed may result in greater projectile dispersion simply due to airframe stress and the corresponding changes to strike points, I think your statement that more rounds would "miss" assumes two things which are qualitative, not quantitative: a pilot's ability and the tactical situation.
Excluding those qualitative variables and approaching the statement purely from a mathematical perspective, I believe that the higher the relative speed, the greater the impact of any projectile weapon deployed.
Yes, the initial reduction in projectile speed would be accelerated in response to the higher initial drag against the atmosphere, but you would still be deploying the projectile at a higher rate of speed from your own aircraft than you would from a standstill and, relatively speaking, if the other aircraft is traveling at a reduced rate of speed, the impact effectiveness would be amplified in comparison to a steady-state speed differential of zero.
Im thinking of it like a car accident. I'd rather be rear ended, going 30 MPH, by an Asian, female driver on a cell phone going 35MPH than be rear ended, going 30 MPH, by an attorney chasing an ambulance going 100MPH.
The relative speed of the attorney is higher and so too would be the impact effectiveness.
Now... someone more knowledgeable... am I over-simplifying this, missing something or am I on the right track?
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Tell you who we need to pop up on here, Remember the Eingineer who really knew what he was talking about? The guy who started the discussion about the ME163 engines and their fuel consumption? Now that's guy I belive, in fact wasn't he some sort of Aero engineer?
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Race? Pyro and HT prolly are as good as engineers, and if they don't, they certainly qualify as far as coding is concerned. And that's what it always comes down to, how to code it.
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.50 cals were *quite* deadly in Korea at jet speeds. 'Nuff said.
Modern rotary cannons and what have you with insane ROF, the problem is not the effectiveness of the individual projectile, so much as that they need that ROF to make the bullet stream "thick" enough that a fighter moving very fast doesn't stand a good chance of "threading the needle".
I don't know if I'm one of the clueless, but I found this thread to be very interesting. I actually read through all four pages, word for word. So, even if I'm overly gullible, thanks Gaston.
"...but an overlooked aspect of this "energy fighting" is the exaggerated effectiveness of the gun armament in computer games; in reality, the higher the relative speed, the weaker the armamament strike. The more energy you have compared to your opponent, the more bullets/shells will miss. In WWII they HAD to stay and maneuver to finish the job, and they could not attack at too high a relative speed."
This, however, doesnt make much sense to me. Like many others here, Im far from an aeronautical engineer - Im a finance guy. I just love war birds and AH gives me the chance to get about as close as I ever will to driving one.
I do agree with Hitech that "energy" is a clearly defined term and you seem to be using it incorrectly... but, that said, and especially in the case of the effectiveness of non-incendiary, non-explosive ammunition, I don't understand the math behind the statement that a higher relative speed results in a decreased armament impact value.
While I'll buy that higher speed may result in greater projectile dispersion simply due to airframe stress and the corresponding changes to strike points, I think your statement that more rounds would "miss" assumes two things which are qualitative, not quantitative: a pilot's ability and the tactical situation.
Excluding those qualitative variables and approaching the statement purely from a mathematical perspective, I believe that the higher the relative speed, the greater the impact of any projectile weapon deployed.
Yes, the initial reduction in projectile speed would be accelerated in response to the higher initial drag against the atmosphere, but you would still be deploying the projectile at a higher rate of speed from your own aircraft than you would from a standstill and, relatively speaking, if the other aircraft is traveling at a reduced rate of speed, the impact effectiveness would be amplified in comparison to a steady-state speed differential of zero.
Im thinking of it like a car accident. I'd rather be rear ended, going 30 MPH, by an Asian, female driver on a cell phone going 35MPH than be rear ended, going 30 MPH, by an attorney chasing an ambulance going 100MPH.
The relative speed of the attorney is higher and so too would be the impact effectiveness.
Now... someone more knowledgeable... am I over-simplifying this, missing something or am I on the right track?
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my mind is aglow with whirling transient nodes of thought careening through a cosmic vapor of invention
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See Rule #4
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Yeah, I never question HTC for any reason. :rolleyes:
I think I was rather polite. If I had chose to be less polite. I could have said a great deal of this stuff does not resemble anything from any valid source material I've ever seen and quite abit in fact contradicts other sources, or the obvious signs the OP does not know anything about ACM, such as framing his ideas about which speeds maximum turn rates may be achieved in terms of TAS instead of IAS.
See Rule #4
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To Shane; I added 3 pages of rules, with a new much more fun firing table, to modify EXISTING rules, and on top of that there are four pages of the most important rules clarified in "plain" language, with extra rule details, and an errata at the end about the H-loop rule. You DO need the original Avalon Hill or Battleline rules...
Each of these cards is a titanic struggle to make sense of the mess of incomplete data that is out there, and there are actually few WWII aircrafts that could be made into an accurate, well-rounded Data Card, so incomplete is the available data. Excluding variants, British and Russian aircrafts, and staying in the late-war arena only, only the F4U and F6F come to mind as being even possible, without just guessing the whole thing, which I already did for much of the Me-163B... The F6F is the only undone aircraft that I REALLY like that could be done accurately. (Note that all but one of the 1/144 scale profiles are done by me, as no accurate thick-line profiles could be found, and this is a lot of work in itself... If I saw a lot of interest, I would do an F6F, and for fun would 70% guess a Ki-84 Frank.)
To Karnak; +25 lbs Spit IX top speed is 1-3 MPH higher than lower power Mk IXs, IF that... Of course, speed was increased +15-20 MPH at lower altitudes. Still, is it not VERY significant that no MK IX ever went beyond about 405 MPH TAS, when the same-engine P-51B, or the MK XIV with little more power, did 440?... Why confuse the issue with what speed the Mk IX gained at SOME altitudes? Putting it another way, excluding the Japanese Military Power vs WEP debacle, show me a SLOWER top speed for a light weight fighter with 2000 HP... (Light weight excluding the Hellcat/Corsair etc...)
To Saurdakar; at 2000-2700 fps of bullet/shell speed, the added speed of an unrealistically high 200 MPH overtake is minuscule. The issue is repeatedly ajusting the aim in a short time; most gun-cam footage show a very tepid overtake... Which is why the damage is more spectacular! And thus the footage is better-known...
Murdr; "What is relevant to the discussion is that it is G-limited".
Hightec; "Your statement that any plane in WWII had its tightest turning radius at 400 MPH is just simply insane."
Well, I didn't quite realize that this was not an accepted fact... If you want the very first clue I had of this, it was a single post by Skychimp, a well-known simmer(discoverer of NACA 868!), 6-7 years ago where he posted two turning radiuses, both at 400 MPH TAS;
Spit XIV; 625 ft.
P-51D (probably metal elevators?); 450 ft. (!!!!)
To put it in perspective, the lowest turning radius I have read for an EARLY A6M2 Zero is 650 ft. at 250 MPH, but I think even an early, lighter-variety A6M5 might do a little better at a lower 200 MPH, say maybe 500-550 ft., or maybe even 450 ft. for the A6M2 ONLY, but that is REALLY pushing it...
So I had just learned that a P-51D at 400 MPH TAS could DEFINITELY out-turn ALL Zeroes at 250 MPH TAS. The world had fallen in...
How come we don't hear of Mustangs beating the Zero's turn as they zoom by it? Well, if you remember my argument above about closure rates and gun effectiveness, especially in a confusing turn like this...
I'm sure Skychimp can be contacted as to where he got the data. I am not making an obscure reference here...
But there's plenty of other clues about this. We even have an extended series of tests done in the 1990s, for Pete's sake!
THEY found out, to their surprise, that the tightest turns were made at or near 400 MPH for the P-47D and P-51D. I'm sure THEY can be looked-up. I don't think there would be that many WWII aircrafts dogfights tests done in the 1990s... The F4U and F6F were there also.
And then, ironically enough, we have a genuine WWII Zero ace, Saburo Sakai, flying a P-51D (in the '70s!), expounding on these amazing turns he did at 500 MPH TAS (because of the speed, I am sure those were done with post-war metal-skinned elevators)... He then said, shortly after mentioning the turns; "Now I know I can place the Mustang in company of the Zero, as the two greatest fighters of WWII!".
Let's examine now how this can be possible, and why the reference to G-forces and CV is ok for pushed-from-behind jet speeds, but COMPLETELY misleading for pulled-from-the-front WWII fighters.
To begin with, this P-51 turn radius of 450 ft., at 400 MPH TAS, is probably not a perfect semi-circle, but more likely a somewhat elongated ellipse, which would "soften" the G-forces on the pilot with some sideways sinking of the aircraft, a-la-FW-190, but probably comparatively more shot-lived.
Then, and probably even more important, is the fact that the Mustang is pulled from the FRONT, NOT pushed from the REAR, while being somewhat posterior-heavy as is well-known. This allows the aircraft to "pivot" around the prop (hence "hanging on the prop"), immensely relieving the pilot of the G-forces because this rotation is achieved by a pivot center close to him or directly on him. In addition, this makes the transfer of blood not constantly uni-directional but rotating/changing, and also more front-to back on the body instead of top-down all the way (especially in the second half of the 180°), softening the blow even more.
You could even theoretically have a radius of turn of o ft. (with lateral mini-rockets as in Battlestar Galactica). The aircraft would then pivot on itself, the pilot as the point of pivot, decelerate BACKWARDS, then accelerate forward again with NO excessive gs on the pilot; 0 ft. 180° turn radius!
Then you have to add that the P-51D also had the first G-suits...
It IS quite shocking that this is true, but it does shows that the entire notion of using jet-era formulas in the prop age is a recipe for confusion. Jets operate in an unforgiving, cement-like air that is like another world from the prop era, and the fact that they are propulsed instead of tracted has a huge influence on how they can pivot on themselves to alleviate the pilot even at medium-low speeds. That the famous Cobra maneuver is seen as a major novelty shows just how uniform jets usually are in maneuvers most of the time, compared to the rambunctious bunch of weirdoes WWII fighters are... Also compare the handling of a front-wheel drive car to a rear propulsion car; quite a difference...
When Kurt Tank said the FW-190 at high speeds could pull x gs per ONE Kilo of pull on the stick, either it was an internal document for a specific use, or the gs were very short-lived, or he was trying to impress an audience by using G-forces as a factor of confusion; it fooled me a long time into thinking the 190 was a tight turner at high speeds... But a SINKING aircraft CAN pull a LOT of gs, and with those types of machines, that doesn't mean it's NOT going down... I hope all those pancaking 190s were not thinking; "hey, with all those gs, I should be ok!..." For sure it was MUCH better, and slower, than hitting nose first like a frozen-stick Zero...
Unlike the jet era, where a given amount Gs WILL match a given rate of turn (although maybe not always so at the very lower range of speeds; ie; the Cobra), in WWII, Gs are little more than a factor of confusion, because they don't tell you exactly what the prop-driven contraption is actually doing... For turn/loops, I always hope to find maneuver DIMENSIONS (more valuable than turn times), and these are not often available. Then I turn to psycho-analysing combat pilot anecdotes... Gulp!
Gaston.
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To Karnak; +25 lbs Spit IX top speed is 1-3 MPH higher than lower power Mk IXs, IF that... Of course, speed was increased +15-20 MPH at lower altitudes. Still, is it not VERY significant that no MK IX ever went beyond about 405 MPH TAS, when the same-engine P-51B, or the MK XIV with little more power, did 440?... Why confuse the issue with what speed the Mk IX gained at SOME altitudes? Putting it another way, excluding the Japanese Military Power vs WEP debacle, show me a SLOWER top speed for a light weight fighter with 2000 HP... (Light weight excluding the Hellcat/Corsair etc...)
You don't seem to understand the effects of 150 octane fuel. It increases speed below critical altitude for a supercharger, it also reduces the original critical altitude, thus a figher will have a similar top speed but at a lower altitude.
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Gaston,
Did you not read my post. This is not "jet era formulas". The diagrams I posted are from 1940 (http://479th.jasminemarie.com/community/Smileys/default/rolleyes.gif).
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To Karnak; +25 lbs Spit IX top speed is 1-3 MPH higher than lower power Mk IXs, IF that... Of course, speed was increased +15-20 MPH at lower altitudes. Still, is it not VERY significant that no MK IX ever went beyond about 405 MPH TAS,
Erm http://www.spitfireperformance.com/spitfire-IX.html 415.5 mph @ 27,800ft. merlin 70
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... I hope all those pancaking 190s were not thinking; "hey, with all those gs, I should be ok!..." For sure it was MUCH better, and slower, than hitting nose first like a frozen-stick Zero...
Oh lord, where to begin?
First of all, if "pancaking" means what I think it does in this context, then the aircraft is in a stall. Certainly an aircraft hitting the hitting the ground more or less belly first with the relative wind more or less *perpendicular* to the chord-line of the wing, then that wing is above critical AoA....and then some. The ability to pull your aircraft into an accelerated stall at a given speed does *not* mean you have bad pitch authority, it means the opposite.
Unlike the jet era, where a given amount Gs WILL match a given rate of turn (although maybe not always so at the very lower range of speeds; ie; the Cobra), in WWII, Gs are little more than a factor of confusion, because they don't tell you exactly what the prop-driven contraption is actually doing...
I could be wrong, but I was under the relationship between speed and Gs in a turn and the turn rate/radius (in the subsonic range anyway) is no more variable or subject to debate than any other law of physics.
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he posted two turning radiuses, both at 400 MPH TAS;
P-51D (probably metal elevators?); 450 ft. (!!!!)
Pure fantasy. That's 75 degrees per second, and almost 24 Gs. I'm almost curious enough to calcuate how ridiculously above CL max that would be....*almost*.
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To Karnak; +25 lbs Spit IX top speed is 1-3 MPH higher than lower power Mk IXs, IF that... Of course, speed was increased +15-20 MPH at lower altitudes. Still, is it not VERY significant that no MK IX ever went beyond about 405 MPH TAS, when the same-engine P-51B, or the MK XIV with little more power, did 440?... Why confuse the issue with what speed the Mk IX gained at SOME altitudes? Putting it another way, excluding the Japanese Military Power vs WEP debacle, show me a SLOWER top speed for a light weight fighter with 2000 HP... (Light weight excluding the Hellcat/Corsair etc...)
You are looking at blower limitations, IIRC. At low altitude, where it could actually get +25lbs boost, it was ~15-20mph faster than +18lb boost Mk IXs.
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Bronk, the Spitfire Mk IX you are quoting at 415 MPH did so at 27 500 ft., and it was a high altitude Merlin 70 engine at +18 lbs, and had nowhere near 2000 hp...
This did not see massive service, and in any case has NOTHING to do with the 2000hp +25 lbs low-altitude engine I was talking about...
I am talking about the mass-produced LF Mk IX at +25 lbs; the main mass of Mk IXs produced. A super climber, but still unusually slow for a lightweight 2000 hp aircraft... Your claim that this 415 MPH top speed is from a 2000 hp +25lbs engine is false, and is clouding things more than clarifying them... I'll concede that this site IS confusing...
Murdr, How do you know how many Gs the P-51 takes in its HISTORICAL 450 ft. wide, 400 MPH TAS turn, when you don't even know the LENGTH of the curve, or how much slippage/rotation/deceleration the aircraft does? Show me your formula taking into account these factors, I'd be real curious to see it...
I've just explained in the previous post how a 0ft. radius, 400 MPH 180 ° turn could have perfectly acceptable Gs. (If quite a long length!)
If you guys really think a 450 ft. wide turn at 400 MPH is impossible, why don't you ask Skychimp where the data came from? I'm sure some of you guys know him better than I do... He posts regularly on Il-2 GD.
If you can't believe the extensive flight tests of the 1990s, that show CONCLUSIVELY the best P-47/P-51 turn rate was near 400 MPH, why don't you look up that series of tests? Its conclusions were in numerous aviation-related sites/articles, and achieved with a fairly large number of pilots... I will try to find the link.
On top of that, those tests are barely 18 years old; I'm pretty sure a good number of these pilots are still around to let some reality intrude here...
Gaston.
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"Murdr, How do you know how many Gs the P-51 takes in its HISTORICAL 450 ft. wide, 400 MPH TAS turn, when you don't even know the LENGTH of the curve, or how much slippage/rotation/deceleration the aircraft does? Show me your formula taking into account these factors, I'd be real curious to see it...
If the diameter of the circle is 450 feet and the speed is 400 mph, it means a whole circle done in about 2.5 seconds. Don't see that one possible, I'm afraid....
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Just a simple question when you seemed earlier to be discussing "Energy" and form to get it, lose it and utilize it. Isn't it so that while in jet aircraft you can "use the weight" of the aircraft to gain engine efficiency by ramming air to turbine in prop planes you really do not gain almost anything in thrust by diving.
By that I mean that while in a tail chase it is beneficial in a jet to go for 0 Gs for some time to gain speed and thus more thrust so you might actually be able to close the gap to the plane you are pursuing where as in prop planes while accelerating you actually gain nothing by diving because the prop does not benefit from faster airflow but only the effect of drag becomes bigger. Of course you might be able to utilize the excess energy gained by diving in speed that will wear out after a while or try to zoom up to target to get a snap shot but all in all you end up in less energy than by simply flying behind your target and trying to catch it in level flight.
If that is true then it probably has an effect how efficient or inefficient certain "energy transfer" maneuvers are in prop planes and in jets?
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"I hope all those pancaking 190s were not thinking; "hey, with all those gs, I should be ok!..." For sure it was MUCH better, and slower, than hitting nose first like a frozen-stick Zero.."
If a plane stalls through a turn it doesn't really create as much Gs as it would with flow attached as the Gs in maneuvers are created by the mass changing its direction. A 190 mushing to ground after a dive is unable to change the direction of its mass and thus unable to create much Gs. The theoretical max AoA of its wing profile is around 16 deg but going straight down it could be more so even while totally stalled the wing would certainly decelerate the plane but how much I cannot estimate. I've been in a similar situation even in AH with 190A8 (quite often actually) that while pulling up from a dive the wing stalls and the plane tries to mush into ground and if you do not ease the stick to reattach the flow it will certainly auger. I'm sure many novice 190 pilots fell for that during WW2 and I'm sure other planes did that too, but of course a plane with high wingloading is more prone to that kind of behaviour. The difference to 190s benefit would have been that at least it had a wing that could handle such accelerations without failing but might also be its shortcoming since the pilots learned that you could always trust the wing to be able to handle the load of any kind of maneuvers, but to keep the load on wing was another matter and in panic many forgot or simply did not know (which is my bet).
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".50 cals were *quite* deadly in Korea at jet speeds."
Not really. There are even some estimates of how many sure kills they lost because of the ineffectiveness of .50s. The enemies went "down" all right, but damaged, not destroyed and due to distance to Chinese border they often got away to fly another day. The Migs were not very effective since, as seen during WW2, cannon armament requires a skilled shooter, where as with a shotgun you are bound to get more hits but with less effect. The deceleration of a light projectile is bigger than that of a heavy and in jet speeds that has bigger effect on effective range than in prop fighters. Of course that is relative also so that a bullet fired from a jet flies faster and further than that fired from a prop plane but in relation to target flying at same speeds the effective range is shorter. I don' think there's much doubt that with 4 20mms in Sabres the results would have been much better. That is due to old wisdom that while fighting over enemy territory you need to carry armament that will d e s t r o y the enemy and not just cripple him, as if he is able to land you are fighting a losing war on attrition.
-C+
"The bellybutton kissing in this thread is amazing. So is the rudeness towards the O/P." Just what I was thinking too... :lol
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Bronk, the Spitfire Mk IX you are quoting at 415 MPH did so at 27 500 ft., and it was a high altitude Merlin 70 engine at +18 lbs, and had nowhere near 2000 hp...
This did not see massive service, and in any case has NOTHING to do with the 2000hp +25 lbs low-altitude engine I was talking about...
I am talking about the mass-produced LF Mk IX at +25 lbs; the main mass of Mk IXs produced. A super climber, but still unusually slow for a lightweight 2000 hp aircraft... Your claim that this 415 MPH top speed is from a 2000 hp +25lbs engine is false, and is clouding things more than clarifying them... I'll concede that this site IS confusing...
Still, is it not VERY significant that no MK IX ever went beyond about 405 MPH TAS
]
Then please be more specific. Which Mk IX are we talking about? Being the the Mk they tried hanging every engine/wing combination off of.. to do every job needed. I'm talking geared from low alt work to high alt photo recon.
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400mph and 450ft radius? Holly G-force, Batman!
http://en.wikipedia.org/wiki/Centripetal_force
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Murdr, How do you know how many Gs the P-51 takes in its HISTORICAL 450 ft. wide, 400 MPH TAS turn, when you don't even know the LENGTH of the curve, or how much slippage/rotation/deceleration the aircraft does? Show me your formula taking into account these factors, I'd be real curious to see it...
Thanks you have just made this a great day , because bursting out in laughter always lightens my mood.
Hmm I believe it was in 4th grade I learned Circumference (I.E. the distance around a circle for the physics impaired) = 2 Pi r = Pi d.
HiTech
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Well, looks like everyone beat me to it. Newtons Second Law, and a little value called Pi that the Greeks discovered a couple thousand years ago. Fluid dynamics without thrust vectoring, exclude or invalidate every rational you've come up with. Since you've ignored my previous post containing lots of info, including period data, there's no need to waste my time explaining anything further, because you have no real interest in the reply.
But we don't need to look up someone who has flown a real P-51, because we have someone right here who just posted ahead of me.
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WOW.
That's gotta be a 10G turn at least, doesn't it? I'm no good with math.
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WOW.
That's gotta be a 10G turn at least, doesn't it? I'm no good with math.
Closer to 25g turn I think.
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"I hope all those pancaking 190s were not thinking; "hey, with all those gs, I should be ok!..." For sure it was MUCH better, and slower, than hitting nose first like a frozen-stick Zero.."
If a plane stalls through a turn it doesn't really create as much Gs as it would with flow attached as the Gs in maneuvers are created by the mass changing its direction. A 190 mushing to ground after a dive is unable to change the direction of its mass and thus unable to create much Gs. The theoretical max AoA of its wing profile is around 16 deg but going straight down it could be more so even while totally stalled the wing would certainly decelerate the plane but how much I cannot estimate. I've been in a similar situation even in AH with 190A8 (quite often actually) that while pulling up from a dive the wing stalls and the plane tries to mush into ground and if you do not ease the stick to reattach the flow it will certainly auger. I'm sure many novice 190 pilots fell for that during WW2 and I'm sure other planes did that too, but of course a plane with high wingloading is more prone to that kind of behaviour. The difference to 190s benefit would have been that at least it had a wing that could handle such accelerations without failing but might also be its shortcoming since the pilots learned that you could always trust the wing to be able to handle the load of any kind of maneuvers, but to keep the load on wing was another matter and in panic many forgot or simply did not know (which is my bet).
Like I said before, not having enough lift available to alter your course is not an elevator authority problem, the 190 can "mush" into the ground in certain situations like this because its wingloading is so darn high.
***
".50 cals were *quite* deadly in Korea at jet speeds."
Not really. There are even some estimates of how many sure kills they lost because of the ineffectiveness of .50s.
Yet still .50s were bringing down jets fighting at high-subsonic speeds. Where does that leave the OP's contention that WWII armaments, many of which were greater than .50s, were too impotent to bring down enemy aircraft except by saddling up and pouring out the entire ammo load? The central problem was always the pilot's aiming abilities and experience.
"The bellybutton kissing in this thread is amazing. So is the rudeness towards the O/P." Just what I was thinking too... :lol
It is ass-kissing or rude to question information that includes, among other things, literal physical impossibilities?
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Found a G-force calculator, thought it was interesting to mess with speeds.
http://www.rcpro.org/rccalc/GForce.aspx
If you were to complete a 450ft radius cirlce at 7G's, you couldn't be going faster than 216.5MPH TAS.
At 400MPH TAS the P-51 would be pulling 23.9G's and would weigh roughly 182,485.93lbs... Empty...
That is 776.53lb/ft^2 wingloading... If it still had wings...
The radius of the circle would have to be 1345ft at 400MPH TAS to keep the G's in aircraft specifications of 8G's.
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At 400MPH TAS the P-51 would be pulling 23.9G's and would weigh roughly 182,485.93lbs... Empty...
That is 776.53lb/ft^2 wingloading... If it still had wings...
Nice to see I didn't mess up the calculations (posted on reply #63)...Or if I did, someone also did it exactly the same way :) Nice find on the flight specific calculator, added to bookmarks.
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Well, looks like everyone beat me to it. Newtons Second Law, and a little value called Pi that the Greeks discovered a couple thousand years ago. Fluid dynamics without thrust vectoring, exclude or invalidate every rational you've come up with. Since you've ignored my previous post containing lots of info, including period data, there's no need to waste my time explaining anything further, because you have no real interest in the reply.
But we don't need to look up someone who has flown a real P-51, because we have someone right here who just posted ahead of me.
HiTech flew a P51 :D
Anyway, ....is Gaston perhaps...Voss?
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To Karnak; +25 lbs Spit IX top speed is 1-3 MPH higher than lower power Mk IXs, IF that... Of course, speed was increased +15-20 MPH at lower altitudes. Still, is it not VERY significant that no MK IX ever went beyond about 405 MPH TAS, when the same-engine P-51B, or the MK XIV with little more power, did 440?... Why confuse the issue with what speed the Mk IX gained at SOME altitudes? Putting it another way, excluding the Japanese Military Power vs WEP debacle, show me a SLOWER top speed for a light weight fighter with 2000 HP... (Light weight excluding the Hellcat/Corsair etc...)
I am talking about the mass-produced LF Mk IX at +25 lbs; the main mass of Mk IXs produced. A super climber, but still unusually slow for a lightweight 2000 hp aircraft... Your claim that this 415 MPH top speed is from a 2000 hp +25lbs engine is false, and is clouding things more than clarifying them... I'll concede that this site IS confusing...
Correct me if i'm wrong but top speed is determined by thrust and drag, weight has very little effect on top speed which is achieved when thrust = drag. A heavier plane will have a higher top speed with the same thrust, if it is aerodynamically cleaner. There is no reason not to compare top speed between the f6f and the spitfire considering weight is a moot point.
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Thrust & lift vs weight & drag.
Increasing weight will increase (lift induced) drag.
cleaning up (getting rid of parasite drag) will help.
But, loading up an aircraft will basically lower top speed.
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Angus , you are correct that adding weight will lower top speed, but when we are speaking of aircraft that travel at 3 to 4 times their 1 g stall spread, the amount of speed lost to induced drag in level flight is very very small.
HiTech
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... If it still had wings...
..or a pilot that wasn't a pile of goo in the seat LOL! At 23.9 G's, the pilot alone weighs more then 4,000 pounds. OYE!
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Thrust & lift vs weight & drag.
Increasing weight will increase (lift induced) drag.
cleaning up (getting rid of parasite drag) will help.
But, loading up an aircraft will basically lower top speed.
aye, i guess i should have said primarily determined :)
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Thanks you have just made this a great day , because bursting out in laughter always lightens my mood.
Hmm I believe it was in 4th grade I learned Circumference (I.E. the distance around a circle for the physics impaired) = 2 Pi r = Pi d.
HiTech
Pie are round not square..... :devil
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Angus , you are correct that adding weight will lower top speed, but when we are speaking of aircraft that travel at 3 to 4 times their 1 g stall spread, the amount of speed lost to induced drag in level flight is very very small.
HiTech
I know. It will do more harm to the cruise and acceleration though, and the stall speed..
Would you know what the different would be on a toploaded WW2 aircraft vs a very light one? (same) A tad hard trying that out in AH except on aircraft with big internal stores.
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Yes, the 450 ft. wide turn at 400 MPH doesn't seem to add up. Perhaps if it was stretched 2000ft., as the P-51 spun on itself, acting as a giant brake... I think Skychimp posted a misprint or something...
The ability of the Mustang to spin on itself controllably at as it slided (at higher level speeds only) WAS useful to quickly gain something like 90-120° for aiming, and was featured in one episode of History Channel's "Dogfights", where a strangely painted yellow-nose Me-109G-10 was shot down in this way, while the actual pilot who had shot it down described this "special" maneuver, and the lucky shot he got as he sprayed gunfire ahead of him in a semi-circle, as his Mustang "spinned" on itself well over 100°.
I have often heard of Mustangs instantly turning the tables on a pursuer directly behind by GAINING 360° inside ONE 360° turn, which means, to cite several specific combat reports, having double the turn rate of the pursuing Me-109G-6 at speeds of about 250-350 MPH TAS (the Messerschmitt's hole between its two turn peaks).
There are dozens, hundreds, of anecdotes of the Mustang appearing near-invincible at higher speeds, and gaining 360° in less than 30 seconds (over 12° per second !), on a turning enemy.
Though that 450 ft. turn will certainly turn out to be a misprint or an error by Skychimp (It really does seem not to add up...), a fact much easier to demonstrate is that the best turn rate of the P-47 and P-51 WAS at speeds closer to their maximum level speeds than the usually assumed 250-300 MPH range. This is supported by combat anecdotes, and by flying tests done with modern instruments less than 18 years ago...
1990s tests. Quote (from memory); "To our surprise, these two aircraft's (P-47-P-51) best turn rates turned out to be quite a bit closer than expected to their maximum level speed, which implied an inability of these machines to sustain their best turn rate for any lenght of time. The P-51's stall at lower speeds was unforgiving, to the point where prolonged combat would not to be recommended, to avoid speed decreasing to a much lower point, making this more of an interceptor. The P-47 also maneuvered less well at lower speeds, but its stall was much more forgiving."
I'll get those 1990's tests for your perusing...
Gaston.
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I was lucky enough to get to know a pilot who flew, fought, and ACED in both the Spit and the P51.
He loved them both. He was not happy going from the Spit IX to the P51, but liked his P51 for the speed and range. When asked which was the better one, he said "The Spitfire". The P51 could not dogfight a Spitfire. However, the P51 was one heck of an offensive fighter, and the German aircraft could not run away from it. But in a dogfighting position he preferred the Spitfire.
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I was lucky enough to get to know a pilot who flew, fought, and ACED in both the Spit and the P51.
He loved them both. He was not happy going from the Spit IX to the P51, but liked his P51 for the speed and range. When asked which was the better one, he said "The Spitfire". The P51 could not dogfight a Spitfire. However, the P51 was one heck of an offensive fighter, and the German aircraft could not run away from it. But in a dogfighting position he preferred the Spitfire.
Who was this person. Just curious.
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Yes I would like to know too.
Despite my criticism of the late Spitfires, I would agree too that it would dogfight better than the P-51 in prolonged duels.
On another subject, I have to admit I porked the high-speed elevator handling of at least 3 of the 8 fighters in my game; P-38L, P-51B/C/D, and the Me-109G-6.
Based on comparative evaluations with the P-51 and its supernatural high speed turn, the two others were porked along with it.
I had assumed that high speed mushing could alleviate Gs, and explain tighter-than-expected high speed turns, but I didn't realize HOW MUCH mushing would be required; at least 2000 ft. of perpendicular braking at 400 MPH, if not more... Not really a turn anymore...
I still think WWII aircraft can mush at these high speed, and that this can help produce tighter turns than one would expect (if the pilots can rave about them!), when combined with the rotation of "hanging on the prop". But clearly, I was influenced too much by these 400 MPH turn radius figures...
Note that the Me-109 still in my opinion has two turn rate peaks, with the second one starting at 400-420 MPH, but, as Hitech said, the second "peak" cannot in any remote way be in the same category as the first one...
The peak turn rate of the P-47 and P-51 cannot be near 400 MPH TAS, but I would still say it is much higher than usually assumed; say 330-350 MPH TAS...
I consider myself fortunate that my game still has five fighters left... I'll fix the three porked ones, eventually...
I guess that's what this forum is for!
Gaston.
http://www.visi.com/~mrowles/Advanced%20Air%20Force.html
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Who was this person. Just curious.
That one:
http://www.geocities.com/pentagon/bunker/3351/allmen/ace.html
(http://www.photos.is/main.php?g2_view=core.DownloadItem&g2_itemId=44822&g2_)
A somewhat remote family member. One heck of a character, and I had one of the best moments of my life sitting between him and this guy:
(http://www.luftwaffe.cz/images/rall1.jpg)
You can pretty much try to guess the subjects....
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I've been reading this post since the beginning (and all the others in this section), but since I don't know much about flying physics I was just trying to learn a bit, and surprised with some of Gaston (lagaffe ?)'s conclusions, especially on the 190 low speed behavior and lately on the spit vs P51 duel issue.
It is well known along AH players that a P51 will get its parts handed by a late war spitfire (spit14 at high alt and spit16 at low alt) in a knife dogfight, the P51 would have to extend kilometres and try to get an energy advantage, which is not easy considering the spitfire climb of rate. It is well known too that a 190 whatever its version has a terrible low speed rate of turn, that compensates its very good high speed handling, especially in dives, making it one of the best "E-fighter" in the game. Both this facts have been accepted for a long time by the AH community, along with some other facts, and that explains why you, Gaston, have met such opposition in your claims on this board I believe.
Gaston, You said you weren't an AH player, but why don't you try the game for a few days, offline (offline use is unlimited) or online and try to compare your conclusions with hitech's ? So this thread, this game and yours get a bit better, cause this is going nowhere ! I'll be happy to fly against or with you, I'm just a gamer that tries to push the envelope of the planes so my view is neutral :) Buy a cheap Saitek stick but a mouse will do...at first :devil
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Though that 450 ft. turn will certainly turn out to be a misprint or an error by Skychimp (It really does seem not to add up...),
The radius of the circle would have to be 1345ft at 400MPH TAS to keep the G's in aircraft specifications of 8G's.
450 X 3 = 1350. SectorNine calculates a nearly equal 1345ft. 450 yard turning circle, not feet.
Misprint or you read it wrong.
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Excellent stuff Gaston. After reading and then later researching WW2 aerial combat, pilots and airplanes I have certainly found it so true, that the more you think you know, the more you know you don't know. There are so many urban myths and glaring errors in the "general" knowledge about WW2 aviation, as well as little or barely known surprising details under the well known facts. Every new book, every interview always brings new surprising things to think about. Your post gives some very interesting new things to ponder at.
Maybe one day we can stick an aircraft with the engine operating into a wind tunnel with super computers and get exact numbers on abilities, even down to scanning thicknesses of armor ....down to the position of the seating and how many g's a guy could take. But until then, all we have is speculation and some real world accounts with statistical data.
Some day! :)
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Concerning the G, the pilot's manual warns the pilot of a more than DOUBLING of the turn time from 250 MPH TAS to 280 MPH TAS!
I think I see a source of confusion here. The English translation says "Turning time at speed". This indicates to me that we are talking about a steady state turn (eg. "sustained turn"). The degrees per second also seems to indicate this is a sustained turn.
The following EM diagram is in a bit different format than the previous ones I posted, and is based on the AH flight model...
(http://www.badz.pwp.blueyonder.co.uk/images/109G6vP-51DSL.jpg)
If we take the speed figure 250 MPH for the 109G under this configuration, and follow the ps=0 line we find the sustained turn rate is at 12.5 DPS. The manual figures work out to 13.8 DPS.
If we take the speed 280 MPH, we find the sustained rate of turn is about 9 DPS. The manual figure works out to 7.1 DPS. Without knowing the power, weight, and altitude configuration of the manual figures reference, that's not too bad of a correlation.
On the other hand if we look at the maximum rate of turn (at a 6 G limit) we find 29.5 DPS at 250 mph, and just under 26 DPS at 280 mph.
Also note that once both planes are above Cv they are subject to the same G force at max dps for a given speed. This particular diagram plots data only up to maximum level speed at the given altitude, and only indicates level turns.
My point is that G load at a given speed and rate of turn is a known factor. Whether we pick an arbitrary 6G sustained unaided pilot limit, or an aircrafts structural limit, the G load at a given speed and dps is going to be the same no matter what type of WWII plane we are talking about.
So when talking high speed handling, the question is whether an aircraft is capable of achieving a given G load/dps. Things like a lower critical mach number, high control forces, or lower structural limits can prevent a given aircraft from reaching a given dps at high speed. The P-51 had relatively good high speed attributes in comparison to it's competition, which leads to it "out turning" planes historically at higher speeds. But that is an issue of the turn performance of the other plane tailing off because of inherent high speed handling issues, as opposed to the P-51 defying the laws of physics.
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Thanks E25280!
I think the explanation of a 450 M vs 450 ft. confusion is very plausible, as I was never able to find that IL-2 thread again...
But a guy expressed scepticism at what HE calculated to be 12 Gs. Also, why the metric/MPH mix? It seems the fault was likely not in my reading...
The fact I couldn't find it again at the time may mean Skychimp had second thoughts about the source, though it was (claimed)official...
If true, It does indicate the Spit XIV would be out-turned significantly by a P-51D at 400 MPH TAS, which is very interesting in its own right...
I still have failed to find those 1990s P-47/P-51 tests, but my quote from memory is accurate as to the most relevant part, except that the moderate "peak turn closer than expected to the top level speed" I NOW put in it, MAY have actually been "peak turn quite close to the top level speed" which is a rather stronger statement, and this contributed to my buying the 450 ft./400 MPH radius, since I felt I could not know the amount of mushing involved, and the exact shape of the elongated curves...
I still think Gs are related to the speed and trajectory only, and that the degrees per second of turn the aircraft's nose actually does may be higher if it spins on itself, which the front-driven prop makes quite possible, and depends on the aircraft type. There are many high speed accounts of P-51s gaining 360° in one turn, mostly against the Me-109Gs, strangely enough, which I think may in part be due to a recurring notion I hear of the 109 not turning well to the right at some speeds. I could not confirm this. It may be related to what follows;
From the Me-109G-6 pilot's manual, this is my recollection of the huge drop in turn rate at 250-280 MPH TAS (posted by Skychimp in IL-2);
21 seconds for 360° at 400 km/h. (This high rate indicates a maximum rate of turn to me.)
27 seconds for 110° at 450 km/h. (This is clearly intended as a warning of a speed-related change.)
You can see why I speak of a "hole" in the turn rate, and this correlate to an observation by pilot Mark Hanna that is I think very relevant to this "hole";
"At 400 km/h the nose abruptly drops, like the aircraft wants to get close to the ground, and you have to pull on the stick to catch it. It is a bit unsettling at first, and you learn eventually to trim it in."
Contrast all of this to the RAF comment; "Surprisingly, the Me-109F can make quite tight turns at 420 MPH TAS."
Or this P-51D pilot vs 109G-6; "We were stuck in the dive (at 500 MPH+), but to my surprise he pulled out of it first."
The first comment is another one of those that oversold me on high speed turn radiuses...
I still think the peak turn rates of the P-47 and P-51 are somewhere above 300 MPH TAS or whatever is generally assumed; it is in the character of these aircrafts that they turned BETTER with speed, though I definitely got carried away with it to say all the way up to 400 MPH TAS...
I will also moderate my view on the FW-190's poor high speed elevators, but I am still convinced, by numerous Allied pilot anecdotes, that its elevator performance above 400 MPH is nowhere near that of late American fighters or the slower-diving Me-109. In Europe at least, it was in a class of its own in mediocrity, and I am convinced Kurt Tank's impressive high speed dive tests of x Gs per Kilo of stick pull reflected a VERY small time frame, which would correlate well with the always good initial turn-in response of the type.
The thread about the horizontal stall-fighting FW-190 ace on this very forum would be very useful to dig up, being full of details about different ailerons the pilot could choose, and correlating as it does with the admonition given to Eastern front pilots to NEVER use the vertical against the Western Allies. He describes out-turning a P-51D at speeds of about 300-200 MPH, to the right, using flaps and the powerful ailerons to "catch" the stall, then shooting it down after a full 360° gain in about three or four turns, maybe even two...
Interestingly, he describes preparing for the fight by REDUCING the throttle before the engagement, to have more reserve power to compensate for the drag of the flaps, and thus not have a decreasing speed in the fight, but one he could MAINTAIN more easily... He describes also the broad wood propeller as a major enhancement, out-accelerating at low altitudes the Me-109G-6, and helping with the stall-fighting.
Correlating this is the well-known, and VERY detailed, P-47D vs FW-190A-5 test, which shows a great superiority of the 190 in turns up to 250 MPH TAS, then a drastic reversal above that, due I think to a combination of improving P-47 turn vs worsening FW-190 turn. The performance and overheating of the P-47 in climbs indicates full 72" MAP 150 octane use, which usually had to be restricted to 65" MAP in climbs.
Returning to the 190 ace, I think this active throttle use is less typical of other fighters who don't have the "brainbox" throttle, and use a narrower range of throttle/pitch/mixture adjustments in combat.
In any case I appreciate the inputs I got here, and WILL fix the relevant aircrafts in my game, though it may take awhile for the fixes to appear on Mike's Air Force Dauntless web site.
I think calculations have limitations in reflecting reality in these subjects, but at least they can put boundaries on the "facts"...
I'll be more wary the next time around...
I hope that despite the errors the info provided was useful.
Gaston.
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From the Me-109G-6 pilot's manual, this is my recollection of the huge drop in turn rate at 250-280 MPH TAS (posted by Skychimp in IL-2);
21 seconds for 360° at 400 km/h. (This high rate indicates a maximum rate of turn to me.)
27 seconds for 110° at 450 km/h. (This is clearly intended as a warning of a speed-related change.)
I thought my post made it obvious I had the referenced document and figures in front of me, and not a third hand recollection...
Turning time at speed 400 km/h. 180° ca. 13 s.
" " " " 450 " 100° ca. 14 s.
Is exactly what it says. (http://479th.jasminemarie.com/community/Smileys/default/rolleyes.gif)
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The peak turn rate of the P-47 and P-51 cannot be near 400 MPH TAS, but I would still say it is much higher than usually assumed; say 330-350 MPH TAS...
TAS is not important here, IAS is.
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Both this facts have been accepted for a long time by the AH community, along with some other facts, and that explains why you, Gaston, have met such opposition in your claims on this board I believe.
Or maybe it was the physical impossibilities.
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I still think Gs are related to the speed and trajectory only, and that the degrees per second of turn the aircraft's nose actually does may be higher if it spins on itself
to turn an aircraft it requires G's, basics physics. No other form of turn rates are ever listed.
HiTech
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Or maybe it was the physical impossibilities.
well that too, except I wouldn't know :D
I still think Gs are related to the speed and trajectory only, and that the degrees per second of turn the aircraft's nose actually does may be higher if it spins on itself
Stalling ?
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Yes Murdr, my recollection was not accurate... What I said amounts to 80 or so seconds per 360, it was more like 50 seconds, from 26 instead of 21, but the basic point I said previously was that it was a vast increase of the turn time, mentioning the correct speeds, which is a huge drop in turn rate for a measly 30 MPH, and that it seems to be related to the nose-down tuck described by Mark Hanna, occuring at the exact same speed.
I've yet to hear anyone commenting on this peculiar behavior when mentioning the 109G, as though it behaves like any other aircraft at these speeds. Even rarer is the mention of the excellent elevator response when trimmed tail-heavy above 420 MPH TAS, which is backed up by numerous combat anecdotes.
As far as the elevator response of the FW-190 is concerned, the above-mentioned P-47D tests mentions turning contests, and the pull-out after a detailed dive description; "rapidly INCREASING turn superiority above 250 MPH (for the P-47). Much better elevator response at high dive speeds, with a far superior angle of pull-out (for the P-47)." Plus numerous concurring combat anecdotes as well...
These points are worth emphasizing, and I didn't see them in AHWiki.
Gaston.
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"These points are worth emphasizing, and I didn't see them in AHWiki."
I think that the reason is that many of those flight tests contain personal impressions of pilots flying an aircraft they are not entirely familiar with and many times there is no measurable data to back up their observations. Some observations are correct but some aren't. Usually only commonly accepted facts are filtered and put to wikis and the relative turning performance between 190 and P47 is not one of them.
-C+
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but the basic point I said previously was that it was a vast increase of the turn time, mentioning the correct speeds, which is a huge drop in turn rate for a measly 30 MPH, and that it seems to be related to the nose-down tuck described by Mark Hanna, occuring at the exact same speed.
Yes, you keep repeating that, and it's obvious you're not going to allow facts to get in the way of your eronious conclusion.
Turning time at speed 400 km/h. 180° ca. 13 s.
This is only about a 2.9 G turn.
" " " " 450 " 100° ca. 14 s.
This is less than a 2 G turn.
These are not max rate of turn numbers.
And this does not indicate what you think it does...
Pitch tends to heavy up above 250 mph but it is still easily manageable up to 300 mph and the aircraft is perfectly happy carrying out low-level looping maneuvers from 300 mph and below. Above 300 mph one peculiarity is a slight nose down trim change as you accelerate. This means that running in for an airshow above 300 mph the aeroplane has a slight tucking in sensation - a sort of desire to get down to ground level ! This is easily held on the stick or can be trimmed out but is slightly surprising initially. Maneuvering above 300, two hands can be required for more aggressive performance. EIther that or get on the trimmer to help you. Despite this heavying up it is still quite easy to get at 5G's at these speeds.
~the late Mark Hanna on flying the 109
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Dang, I sure hope the bit about the Komet wasn't wrong too, that's all I'd really paid attention to out of the first post.
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moot
Me-163B: No emphasis in AHWiki on the fact that the Me-163B climbs FASTER and FASTER as the altitude increases! At 40 000 ft the Me-163B's climb rate is almost DOUBLE what it is at 10 000 ft! This unique feature is due to the decreasing air density that does not affect the non-breathing rocket engine. I have heard the figure that, at this high altitude, the horsepower equivalent is 9000... The Me-163 had a good wingload EMPTY, but the turn performance varied in minutes as burning fuel halved the weight(!). Empty or not, the design had a lazy pitch response, like all tailless designs, but roll was optimized for high altitude and excellent, although it apparently became heavy and lazy at low altitude(this from a well-known P-38 combat account)...
I do not have the specific numbers at hand,so I do not know if doubling is correct, but once again the conclusion is completely incorrect even if the facts are.
Yes air density drops with Alt while thrust does not, but this is the minor factor in the increased climb rate. The big factor is simply burring most of its weight in fuel while maintaining a constant thrust. The fuel burn rate is so high, that computing and documenting climb performance becomes problematic.
So when statements like At 40 000 ft the Me-163B's climb rate is almost DOUBLE what it is at 10 000 ft!
are made , they are completely misleading. Because what is really meant is that the 163 climbs twice as fast at 1/2 the weight, to which most people would say "Well Duahhh"
HiTech
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Thanks.
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Gaston...one of the anecdotes:
"Or this P-51D pilot vs 109G-6; "We were stuck in the dive (at 500 MPH+), but to my surprise he pulled out of it first.""
Does it have any more data?
A 51 would stay in the dive with a 109, or start closing in on it. So would a P47. If a 109 started first, say after a merge, it does have some distance to work with. The 51 may have been doing more speed when the 109 pulled up.
BTW, in one of my first WW2 books I read, there was an account of a Spitfire chasing a 109 into a dive (I actually think they were 2) of which neither recovered. Take it with a grain of salt, - read it some 27 years ago.
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-To Angus; I'm afraid there is no more data on the P-51D vs 109G combat I described, but it should be noted that the P-51D was noticeably slower in top speed in the dive than the B/C models, and all U.S. pilots were well aware of it, despite some apparent lack of "official" warning about the actual extent of the loss... So the margin in speed would have been much smaller vs the 109, especially if the "G-6" was a smoother later G-6/14AS model... In addition, at higher altitudes, the porpoising effect of the bubble top Mach number had an effect closer to 30MPH in speed reduction or maybe more... Also the chase could go on a long time because at higher altitudes the initial acceleration in the dive of the 109 was apparently noticeably greater, which would give it a sort of head start.
The B model was substantially faster in the dive, but was subject to unpredictable failures throughout its airframe; wings, tail etc... So it is not clear to me how much of that extra performance was actually used. Despite an "on paper" parity, the P-47 was much more esteemed by U.S. pilots in the dive...
As for the 109 versus Spitfires pull-out, note that the critical aspect is whether or not the tail-heavy tailplane trim was used. Numerous German pilots confess later in interviews that they did not use this feature when it could have made a huge difference. One of the top Finnish ace described almost going into the ground, and when asked about the trimmer, he had to admit he was so caught up in the action he did not even think of it... Also, the trimmer had to be used early in the dive or it became too hard.
It was an unnatural device to use, and, if pre-set tail-heavy, required the pilot to push constantly on the stick to maintain level flight, probably at a cost in speed too. This would probably also rob some of the great initial dive acceleration of the 109, which was a tempting but ultimately fruitless tactic against U.S. fighters. One U.S. pilot said; "They would keep diving; they never seemed to learn".
-To Murdr; Quote; "180° in 13 sec. at 400 km/h. This is only about a 2.9g turn. .... 100° in 14 sec. at 450 km/h is less than 2gs...NOT a maximum-rate turn."
If you take into account that the second part of the 360° would be done at a slightly slower speed, thus at a slightly higher turn rate, it is not unreasonable to say that this is a 22-24 sec. 360° turn. Even at the full 26 seconds, this is almost an exact match to Russian tests that pegged the 360° turn rate of a G-2 at 20-21 seconds and of a G-6 at 22-24 sec., speed unspecified. A rate of 15°/second does seem low compared to a roll rate of 80° sec, but not out of line with film footage... If they can do 30° sec. for a full 360°, then I would be interested to see the data. My impression of WWII footage is that they are all surprisingly slow in turns, but if a 10 sec. 360° is possible, then I definitely want to know...
A doubling from a conservative turn rate, seems logical, but if peak turn rates are supposed to be much higher than this, then pulling 4Gs would require according to you a 360° circle completed in 10 sec. I've never seen such a figure, but that doesn't make it impossible. My impression is that pilots did not suffer greatly from continuous Gs at 400 km/h, but briefly suffered at 500 km/h and above...
Even the Yak-3 could do no better than 18 sec., so if a 26 sec. 360° at 400km /h to 50 sec. 360° at 450 km/h is a drop in the sustained turn rate, it must be entirely due to a lack of acceleration power in the engine above 400 km/h; possible, but sudden and large?
Yes, Mark Hanna mentions 5 Gs at much higher speeds, but notice that the elevator authority over the 109's attitude is always good.
Gunther Rall (109G-6, NOT the P-39 collision); "I was going down too fast and pulled on the stick to avoid him, the aircraft responded nose-up but despite this kept going down. There was a terrific crash..." I do remember this was NOT a prolonged dive, but a very short one.
This is just like the 190 tests with Kurt Tank's x(7?)Gs per Kilo of stick pull at very high dive speeds; impressive-sounding, but what if it was for a mere one second? Mark Hanna does not say how long these 5Gs were sustained, and we know even less about how the 109's trajectory responded. If sustained then it would indeed mean I am wrong about the 109 performance "hole". It is a "hole" in sustained turns only then, due to a fall-off in engine acceleration?
This "hole" in peak turning performance as I "see" it would explain why the 109 is often portrayed in U.S. combat reports as slower turning than the 190, when Russians reports rave about the 109's turning ability and berate the 190; U.S. fighters could keep the speed just high enough to spend most of the turning combat in the worst possible zone of 250-280 MPH, where even the 190 had no such "falling off the cliff" in its turn rate.
In another issue, the notion that the 190 has great pull-out and turn performance in prolonged high speed dives has NEVER been verified/described in any test and combat report I have ever seen. Even Eric Brown's highly favorable view of the 190 underlines politely the "tactical restriction in pull-out from low-level dives". In other words, a truly superior diver as long as the ground is really far away...
As for the Me-163B issue, Rudy Opitz mentions in an old article that at 15000 ft., or so, the climb rate was at a given value, while at an altitude of a mere 10000 ft. more, the climb rate increased by 40 or so %. Sorry about the exact figures, but my game's Data Cards are designed for play... Yes the weight in fuel diminished, but the moderate acceleration described as "surprisingly slow" at low altitudes became so ferocious at higher altitudes that the warning for Mach overspeed had to be changed THREE times, from a blinking light, to a light with buzzer, to a light higher in viewpoint, with a LOUD buzzer(Opitz)... In "Warplanes of the Luftwaffe", p.226, the acceleration at the top of the climb is described as 250 MPH to 600 MPH "in seconds", while I have seen at least one reference to the high altitude power being equivalent to 9000 hp...
On another subject, here is the Lockeed roll rate chart of the boosted-aileron P-38L;
http://home.att.net/~ww2aviation/P-38rollchart.JPG
It does illustrate my point about unpredictable performance. Sadly, there is so much incomplete info on so many of these aircrafts, that especially on the axis side (most particularly the Japanese!) some significant features will remain forever obscure...
I will try again to find those 1990s P-47/P-51/F4U/F6F tests, as I have found them to be very significant, but at the time (long ago!) I could only jot down the info... These however did NOT specify the exact peak of the P-51/P-47's turn rate, but I am sure now the actual sentence was "surprisingly,...quite close to the max. level speed." I would agree this cannot mean anything close to 400 MPH, but at the very least it does suggest something more than 300 MPH, especially when combined with the poor rating they gave the P-51 for sustained turning combat. Note that many official documents of the time, with smooth progressive curves, turn out to be calculated even when no mention is made anywhere of this...
As Socrates said; "The only thing I know is that I know nothing!"
Gaston.
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Gunther Rall was caught by a hail of bullets while fighting P47's high up. He kicked his 109 into a completely insane dive and recovered right above the deck, only to find out that the P47's were right on his tail. So he bailed.
His words were that the P47 was faster in the dive.
I have an excellent account about P51 diving vs 190. (Tony Jonsson).
The P51's encountered 190's at higher altitude, but went in to attack. The 190's tried to run by climbing. Starting at 12K, the P51's caught the 190's at 22K. The 190's then did split-S, and headed for the deck. The P51 quickly caught up with the 190 and fired, then was forced to pull aside so he wouldn't overshoot. It ended with a GL turnfight where the 51 got the better.
190 vs 109 in a dive?
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One U.S. pilot said; "They would keep diving; they never seemed to learn"."
Interesting comment but does not really make the choice to try to dive out of harms way a tactically wrong choice, quite contrary. I'd imagine that many veteran pilots told the young and inexperienced pilots to always dive away if they got into trouble while flying over Germany. The point was not only to get away but also bring the enemy lower and possibly to reach cover of your own light flak, get help from your friends possibly still a bit higher and reduce the amount of threatening aircraft. In similar situation I'd always dive but not all the way to ground level but to bring the enemy to a more disadvantageous position and to make it easier for him to make the decision to go somewhere else. In fact for an escorting fighter any enemy fighter diving away is a "mission kill" helping to achieve their goal, which is after all to keep the bombers safe and not to hunt for personal glory, which many probably did, and in turn any escorts breaking away from escort duty is also "mission kill" for the escaping attacker.
So the diving was not necessary an erroneous trust in superior dive characteristics of German rides but merely a valid tactical choice to get to safety.
-C+
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To answer Angus,
The FW-190A initially accelerates as well or better as the Me-109G in a dive, and can reach much higher speeds between 30 000 ft. and 10 000 ft.. Apparently, in dives the Me-109G accelerates slightly less well from low altitudes, but although it has a 50-70 MPH lower top dive speed throughout, it can keep what it has much lower to the ground, because with its tail trimmed heavy, the pull-out is much better.
Below 10 000 ft. it must begin its pull-out, or will fail to recover from its incredible top dive speed of 600 MPH, which astounded Russian testers... The Me-109G is far behind at about 520-530 MPH, the limit at which the ailerons start to flutter, making it impossible for the pilot to "center the stick". I've always been puzzled by Gunther Rall's long escape, and I think he kept the speed below 520 MPH by maneuvering violently, which also slowed down the P-47s if they did not want to get in front...
The P-47D is in the same class as the FW-190A, but has slower dive acceleration (based on tests with paddle-blade props vs P-51D, but not in tests with needle-tips prop vs P-51B, where the acceleration in dive was comparatively much better for the P-47???)with the luxury of pulling out much later, with a much better recovery.
The P-51B is close behind these two, with the D slower but safer(?). There were wings pulling out and other issues...
To answer Charge, it seems to me the flak was often "unfriendly" and a bit far away to help at 20000 ft. or more. I think an overlooked issue is that German fighters did not have enough fuel to wait for the raids at high altitude (CAP), both in internal endurance and overall quantity. I think the relative performance of their aircrafts suffered from the long climb to battle, and thus they could do little but dive. An indication of this is that their kill/loss ratio was 1/1 at low altitudes, 1/5 at high altitudes...
Hope this helps.
Gaston.
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Well, they were not up there to kill fighters at that point.
Anyway, then both the P51 grabbing the 190 as well as Rall being caught do not make sense. Yet this happened.
Rall actually claimed 900 km/h (I think he said 1000 though), which leaves him at 560 to 620 mph.
I do have an account of a Hurricane exceeding 500 mph in a dive by some number (500 was the highest number on the Mk II gauge). It did recover, but now with a dihedral of 3 degrees and some parts missing !
And the record-breaker, - a Spitfire. Doing 606 mph, which makes Rall's claim unlikely.
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then pulling 4Gs would require according to you a 360° circle completed in 10 sec.
I'm not sure where you got to the "according to you" conclusion.
Refering back to this AH flight model, but phisics based graph...
(http://www.badz.pwp.blueyonder.co.uk/images/109G6vP-51DSL.jpg)
We find a 4G peak rate of turn is at about 25.25 dps.
However, refering back to the Aircraft production minstries spitfire EM diagram:
(http://www.badz.pwp.blueyonder.co.uk/Files/Images/Spit1a.jpg)
We can see at the data point indicated by the red circle, that at 12k the spit1 could sustain a 250 TAS 5G 360 turn in under 15 seconds if it decended at a 16 degree angle. To sustain a turn at 250 TAS without altitude loss, it would instead be slightly under 3Gs at about 27 seconds to complete a 360. To get a better rate we would have to slow the turn down to corner velocity. Then the level turn (on the diagram) would be at 160 TAS only taking around 19 seconds to complete a 360.
Have to go for now.... to be continued....
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so if a 26 sec. 360° at 400km /h to 50 sec. 360° at 450 km/h is a drop in the sustained turn rate, it must be entirely due to a lack of acceleration power in the engine above 400 km/h; possible, but sudden and large?
Yes exactly. The closer you get to top speed, the quicker the sustained rate of turn drops off. We can see that in a typical level turn E-M diagram...
(http://www.badz.pwp.blueyonder.co.uk/images/Corner.jpg)
This annotated diagram may be easier to show it. See how all three Ps=0 lines takes a nose dive as we approach the maximum level speed for the tested altitude? Anywhere along the Ps=0 line, you can sustain that turn rate at that power setting and speed indefinitely in a level turn.
If we change our thrust output, the Ps=0 line is going to change. Obviously the lower the available thrust, the lower the best sustained rate of turn and speed are going to be. So when you reference the P-47D-4 with the Curtiss Electric C542S propeller, vs the captured FW 190A3, I can see why at lower speeds the 190 faired better in that match up. Even though the P-47 has a more favorable stall boundary for turning and can turn a slightly tighter radius, the 190 can sustain a better rate of turn. The lack of the later paddle bladed props on the 47D-4 probably only exacerbated the power deficit situation. However when we take the speeds closer to the two planes corner velocity, the P-47s better instantaneous rate of turn, and smaller turning circle changes the outcome. So I also question your conclusion about the high speed handling of the FW 190. Everything I've ever seen says that the stick forces were generally light and not objectionable at high speeds. That single test only displays the difference between their sustained and instantanious rates of turns, and doesn't indicate that there was some problem with reaching the max AoA in the 190 at speeds above 250.
Oh, and it's too late to edit my previous post so...
To get a better rate we would have to slow the turn down to well below corner velocity. Then the level turn (on the diagram) would be at 160 TAS only taking around 19 seconds to complete a 360.
:uhoh I had to leave the computer and didn't really get a chance to proof read...fixed :salute
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Always illuminating, Murdr.
I love this forum, even if I only lurk here :D