[Gaston]

Originally Posted by IceFire

I'd first like to ask why the German and Russian reports are better than the British and American ones?

Because German tests by stating the obvious: IE: the P-47 turns better than either the Me-109G or the similar performing P-51, they get something that matches the blindingly obvious from all air battles.

I defy you to find any WWII air battle anywhere where the Me-109G was even in the same league in low speed sustained turns vs the P-47: That very notion is laughable... This gives you an idea what the US tests a are worth when they claim: P-51 gets on a P-47's tail in four turns...

WWII Test pilot conclusions are generally laughable, with even one German one assuming as a matter of course that the Me-109G out-turns the FW-190A when comparing to a La-5. Laughable...

Bullets flying apparently inject a lot of objectivity into comparative flying...

Russian front-line observations are that: Observations of combat, so they rank far above what any test pilot says. And what do you know, the Russian's combat observations don't conclude the FW-190A is out-turned by the Me-109G...

Originally Posted by IceFire

Moving along... as far as sustained turn information goes what you've got seems to be contradicted by other sources although it does seem that the RAE tests for the Bf109 suggest a horrible turn rate in all related tests with a variety of different aircraft..

Well horrible if the P-51 was considered horrible by them too, which it wasn't, so the British conclusions here can be safely be considered as bunk as well... Which is why I don't worry at all to see Typhoons holding their own with FW-190As: Have you ever read any British tests concluding the Hurricane easily out-turns the Spitfire? No? Why not? It was completely and utterly true, and widely known among combat pilots...

Gosh, why the discretion about the Hurricane's sustained turn superiority over the Spitfire all of a sudden? Not iconic enough maybe? Or not fitting flight physic theories?

See why I'd rather ignore whatever test pilots in those days have to say?

Originally Posted by IceFire

I would like to point this one out: http://www.wwiiaircraftperformance.o...-47c-afdu.html

All kinds of interesting statements about the P-47C versus other types. Unfortunately not a later model being used but best I can do right now.

Versus the Mustang Mark X (P-51B prototype)
"The rate of roll of the P-47 is considerably better than that of the Mustang, which cannot follow sudden changes in direction. In rate of turn, howeverm the two aircraft are practically identical."

Well for the rate of roll it's bunk, since roll rate charts show little difference, though you hear about the P-47's roll reversal being good...

You know what to think of the consistency of test pilots when here they are equal, and then on later models the P-51 supposedly reverses a tailing P-47 in four turns...

Four turns... Think about it: Going from roughly equal to gaining 90° for each 360°...

Vs the Model 52 Zero the P-47 was also reversed in ONE 360° turn from a full 360° tailing position (.5 turn to .75 turn from the tested 180° opposite merge), P-51 nearly one full 360° turn from 180° opposite merge, (or a bit below 2 X 360 turns for a full 360° tailing reversal), and a full turn for the P-38 from 180° opposite merge, (or a full two 360° turns from a full 360° tailing position), making it the best "turner" of the 3...

Unsustained turns have nothing to do with sustained, so these results are meaningless for more closely matching European types, assuming they even got the hierarchy correct for sustained turns (gravely doubtful here since these may not even be sustained)...

Note I have no idea what the P-38 can do in turns. For Europe it is not important enough for me.

The P-47 coming dead last behind the P-51 is just a laughable conclusion when you've read any amount of P-47 combat reports, and compared them to a similar number of P-51 combat reports, as the Mike Williams site lets you do.

So what if its only 600-700 reports apiece: Do I have to take your whole blood to know what's in it?

I know all the reports that are contrarian to what I say, including the one vs the Zero: Either the late Bubbletop is really much worse than a Razorback, or it's typical test pilot nonsense you will find not a clue of in real battles.

I go with the real battles because after 17 years of looking at this, I noted they have one huge advantage over test pilots: They all say the same things, while those guys go all over the place...

Find me ONE P-47D out-turned in sustained low speed turns by a Me-109G...

Find me ONE FW-190A out-turned in sustained low speed/low altitude turns by any Mark of Spitfire...

See what I am getting at?

Originally Posted by IceFire

Versus the Spitfire IX
"The rate of turn of the Spitfire is naturally superior to the heavier P-47 and in turning circles it was found that after four turns the Spitfire could get on the P-47’s tail and remain there with a chance of shooting with correct deflection."

My advice to them is: Put bullets and cannon shells in those things, with orders to shoot, and see what happens with their theories...

Originally Posted by IceFire

And then this:

http://www.hawkertempest.se/TacticalTrials.htm

Comparing the Tempest Mark V (Series I, unboosted ailerons)

Versus the Typhoon:
"Very Similar. Any difference appears to be in favour of the Typhoon. This is too slight to alter combat tactics."

Versus the Spitfire XIV:
"The Spitfire XIV easily out-turns the Tempest. "

Versus the Mustang III:
"The Tempest is not quite as good as the Mustang III. "

Versus the FW190:
"There is very little difference in turning circles between the two aircraft. If anything a very slight advantage lies with the Tempest."

Versus the Bf109:
"The Tempest is slightly better, the Bf.109G being embarrassed by its slots opening near the stall. " <---- I honestly don't believe that the Bf109G would be worse than a Tempest, Typhoon, Mustang or FW190... but this is what is said here.

So by all of these tests it would suggest the Spitfire is easily the top contender in all turn rate comparisons beating everything tested against it. Then you have the Mustang and Thunderbolt which are on similar levels. Then you have the Tempest and Typhoon and FW190A which all seem to inhabit the same turn abilities. Then, for whatever reason, the Bf109G which seems to have the worst... which is counter to what I've read from a German pilot account.

They also said the Spit Mk XIV generally out-rolled the P-51 Mustang, but then in the pilot notes of that specific test you can read:

"The Spitfire's ailerons were defective, but will be fixed in production..."

Hmmmm...

I estimate the actual Wartime top roll rate of a Mk V to be around 78-80°, reduced to 50° on the Mk IX/Mk XII, and a paltry 40-45° on the Mk XIV...

I know there are Mk Vs quoted at 100°+, but I think this could be helped by high altitudes, where on some types roll did get faster.

This Jives with a Supermarine factory pilot who said the Mk IXs was only 2/3rds as fast rolling as the Mk Vs, and the Mk XIVs worse still...

The peak roll speed on all Spits is also much lower being around 160-200 MPH, while on the P-51 at 90° it is closer to 300 MPH...

Don't rely on what the Spits can do today in airshows: They are much faster today because the aileron hinges have been completely re-done mechanically, and they have no guns or ammo...

So you can see how unlikely it is to say the Spit "generally" outrolls the P-51during wartime, especially with "defective" ailerons...

Just take what the period's test pilot say with a grain of salt is my motto: Every battle matters more to me than whatever they say...

Originally Posted by IceFire

This is from Osprey Aircraft of the Aces #6: FW190 Aces of the Russian Front by John Weal:

Hauptmann Heinz Lange:
"I first flew the Fw 190 on 8 November 1942 at Vyazma in the Soviet Union. I was absolutely thrilled. I flew every fighter version of it employed on the Eastern Front. Because of its smaller fuselage, visibility was somewhat better out of the Bf 109. I believe the Focke-Wulf was more manoeuvrable than the Messerschmidt - although the latter could make a tighter horizontal turn, if you mastered the Fw 190 you could pull a lot of Gs and do just about as well."

So at least one German pilot seems to think that the Bf109 was better in the horizontal. His point of comparison may be Bf109E or F series as he was with 3./JG 51 and with I./JG 54 previously according to the book.

I don't understand why wing loading is reduced when throttled down? Please explain.

Heinz Lange partly confirms what I say all along:

To understand him, you have to have prominent in your mind the distinction between high speed unsustained 6G + turns (In which no doubt the Me-109G can beat the FW-190A, despite its much heavier elevator controls: The lightness of the FW-190A's elevators not translating into actual turn or dive pull-out performance: Nose-up sinking, remember?), and sustained low-speed 3 Gs turns, which is what I am talking about:

"although the latter could make a tighter horizontal turn": IE: A tighter unsustained high G radius, "if you mastered the Fw 190 you could pull a lot of Gs and do just about as well." That is, in the long run, if you were patient in sustained turns, you would find them about equal (but not with the FW-190A's flaps down I'll bet, a trick that came later)...

Originally Posted by IceFire

I don't understand why wing loading is reduced when throttled down? Please explain.

One aircraft being better at high Gs will not necessarily be better at low Gs. This is because depending on aircraft types, the engine loads the wing with different proportions of leverages according to speed, which the geniuses of those days don't know about, since they never actually measured the wing bending in turning flight in those types of nose-pulled machines...

A long nose type with big wings may have nearly 50% of its lift caused by the engine alone, putting the wingloading higher than a short nose small wing type at 3 Gs (actual turn 3G on pilot), since the big wing type bends its wings nearly like 6 Gs when the smaller wing type only get one extra G from the engine's shorter nose, so 4Gs of wing bending for the same 3 Gs of turning...

But at 6 Gs the big wings regain the advantage, since they still get only an extra 3 G of engine-caused wing bending over the 6 Gs of actual turning, so 9 Gs of bending (they can typically take 13-14 Gs without deformation), while the small wing short nose type has now to take 6 Gs plus one: 7.

9 to 7 Gs of wing bending (at 6 Gs of actual turn) is a lot closer than 6 to 4 Gs of bending (at 3 Gs of actual turn)...

Now if the small wing short nose also happens to be a lot heavier, then 9 to 7 is close enough for the big wing to beat it easily, when it couldn't do so by a wide margin at a 6 to 4 Gs wing bending ratio in the lower sustainable 3 Gs...


I understand now how this leap from engine power to wingloading was done, but it is much more complicated than it first seemed to me when I realized this about ten years ago: The CL must shift in front of the CG to relieve the pilot from the forces of curving the prop's trajectory. The amount of this prop "turn curving" effort depending on the surface of the prop pulled below potential forward speed: The larger the surface, the larger the slanting of the thrust, the larger the slanting of the thrust the more lift is generated through the actual induced angle of attack: 7° is worth 20 000 lbs of extra lift?, add 6° of thrust slanting (13° total) and you could be close to 40 000 lbs of extra lift, but maybe all that extra force is now working only with a four inch "forward shifted" lever to lift the nose's 10 foot distant unwilling prop...

For all that extra lift to be there, in addition to the thrust angle slanting down, the airflow "void" above the wings must deform throughout the turn and increase in depth to lift things more up by the same amount, which is why wing bending measurements during turning flight would show if this is going on (this measuring never done in flight and in turns, AFAIK, on these types of WWII fighters)...

In theory the CL is always behind the CG for stability (but the prop now resisting you pulling back on it makes this moot for stability in a turn: The prop's resistance creates stability far more forward), but I think this is not true while turning: The airflow's void above the wing changes shape -in a curved turn's airflow- and moves the CL forward, which is why the pilot never feels like he is fighting, with his elevators, hundred of pounds of force on a prop that wants to go straight and not in a curve: The effort is taken over by the reversing direction of the "scissor action" when the CL shifts in front of the CG.

Otherwise, with, say, a tail as long as the nose, the elevator's action would be only a 1:1 lever to defeat what I think is about 100+ lbs of resitance per 1° of AoA increase at the prop (which does not like assymetrical incoming airflow, because it wants to go straight), or 700 lbs total at 7°: Beyond structural tail strenght almost...

The wing's lift is greater but operates with maybe a 30:1 lever agaisnt the prop on some types, depending how far the CL has moved forward and how long the nose is. (Exactly why the Dora can't compare to the Anton in sustained turns...)

All that "induced" extra lift would produce extra drag, but two objections come forward: Extra drag compared to what? Other nose prop types? No. To a similar size and wingloading jet, yes.

You will then find the jet out sustained-turning the prop aircraft despite the jet having a much lower climb rate and acceleration, which is exactly the case of a Vampire vs a Spitfire Mk XIV... Despite nearly identical wingloading, the Vampire gains in low-speed sustained turns to the tune of 90° to every 360° vs a Spit XIV... Four turns to reverse a tailing position, despite a far lower climb rate and acceleration...

The other "masking" factor of the extra lift/drag of nose props in turns is that when the prop fights being made to curve in a turn, its thrust is not reduced but actually increased on the inside-turn part of the prop: It's increased inside-turn efficiency is actually what cause the thrust to slant in the first place. So an increase of prop efficiency on the inside-turn part of the prop disc (because of slower incoming air in that area) could mask some of the extra drag with extra thrust...

Mind you, the only pusher prop fighter to see front-line service was not that great a turner: Maybe the SAAB 21 had a balance problem that did not affect the Vampire... This does strike against the notion that a pusher prop should have enjoyed a "real" wingloading advantage... All sides tried and tried to make a pusher during WWII, but this was the only one to ever see some service...

That's my "proploading" theory anyway, and it does jive nicely with this doesn't it?:

http://www.spitfireperformance.com/m...an-24may44.jpg

Gaston