Bf-109 vs P-40

BTW
Soviet figure for 360deg turn for P-39D-2 was 17,7-18,7 sec, wing armament in place and for P-39Q-15 20-21sec, without gunpods.

Juha

Soren said:

Sorry Demetrious but you need to read some more then.


Herbert Kaiser, German fighter ace. 68 victories.
"Personally, I met RAF over Dunkirk. During this battle not a single Spitfire or Hurricane turned tighter than my plane. I found that the Bf 109 E was faster, possessed a higher rate of climb, but was somewhat less manouverable than the RAF fighters. Nevertheless, during the campaign, no Spitfire or Hurricane ever turned inside my plane, and after the war the RAF admitted the loss of 450 Hurricanes and Spitfires during the Battle of France."

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450 Seems a bit on the high side don't you think maybe ?

BTW At risk of appearing super-thick, I really do not understand 'inches' of manifold pressure in a lot of the reports referred to on this thread.

Can anyone explain please ? this is something I seem to have struggled with for a while.

Thanks.

Cromwell said:

BTW At risk of appearing super-thick, I really do not understand 'inches' of manifold pressure in a lot of the reports referred to on this thread.

Can anyone explain please ? this is something I seem to have struggled with for a while.

Thanks.

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It's the amount of pressure in the intake manifold measured in inches of Mercury.

Hello

Soren said:

Believe what you want VG-33, but I prefer to believe in what is actually physically possible.

To me there's no doubt that the Bf-109 turns tighter than the P-40.

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Listen Soren, i might be not as good in engish as you, and assume it. But you use improper worlds:

- you'v got the belief that 109 E/F turns better than P-40C/E.
- I shaw you by concrete soviet test figures, that physically P-40 turns better than Bf 109, even in very favourable test conditions for the german plane.

Can you make us the mathematical demonstration that Bf 109 turns better?

VG-33

VG-33

claidemore said:

I have no problem believing that the P40 had a small turn advantage over the 109, but I also believe that the 109 was superior in many other areas, and the overall better fighter.
.

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Not that small, 18 (P-40C) against 20,5 ( 109F) is a confotable 14% advantage. Now, was the Bf 109F 14% faster?

Regards

Cromwell said:

BTW At risk of appearing super-thick, I really do not understand 'inches' of manifold pressure in a lot of the reports referred to on this thread.

Can anyone explain please ? this is something I seem to have struggled with for a while.

Thanks.

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I'm no expert but believe the following to be correct.

+18lbs (British) is approximately 66" Hg (American) or 168cm (Soviet), the latter two being mercury displacement at the manifold (absolute pressure) and the British being positive manifold pressure (where neutral has neither vacuum nor pressure but is ambient).
Germany uses boost bar, so 1.42 atü is roughly equivalent to British +6lbs like you might see in a Merlin II.

1 bar (14.5 psi) is not the same as 1 ambient atmosphere (14.7 psi), so when using conversion tables for German aircraft this needs to be kept in mind.

Also, dynamic boost pressure is modified by valve timing. The same engine with camshaft overlap will record lower boost pressure in bar than a more sedate camshaft grind using the same supercharger (absolute manifold pressure will remain about the same). It is also modified by the method being used. You get lower readings of boost pressure in bar than what you do measuring absolute manifold pressure, for the same supercharger on the same engine.

I think this is because mercury of displacement is measured on a static manifold (ie. a flow bench), where bar is a dynamic measurement which takes into account some amount of engine vacuum. I don't know if the British "positive/negative manifold pressure" system is dynamic or static.

Marcel said:

He did in a pdf, earlier in the thread.


.

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Big your pardon? I red all the treads from n°1 to his n° 65 and saw no explanation about them. May I have missed something.

VG-33 said:

Big your pardon? I red all the treads from n°1 to his n° 65 and saw no explanation about them. May I have missed something.

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saw we are at over 200 topic here maybe it's after
see topic 130th

Cromwell said:

450 Seems a bit on the high side don't you think maybe ?

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I believe that is the correct number,not incl. the bombers lost. Few seem to realize just how ferocious the BoF was in terms of aerial battles.

Juha said:

IMHO the Soviet table is rather good but of course only a rough guide, giving info only on one kind of turn and without info how much skill was needed to achieve optimum turn performance.

One must notice that Soviet tests gave very nearly same results than those the Finnish got entirely independently, Bf 109G-2 22sec and I-153 12 sec.

On HoHun's tables I noticed one oddity above all, according to him Fokker D.XXI turned better than Curtiss P-36A, that was clearly contrary to all FAF pilots opinion I have seen, and some of them had flown both Hawk 75As and Fokker D.XXIs many times, even tested them during same day. On the other hand some HoHuns results were in line of what FAF pilots have told.

And of course turning ability was important to fighter but less important than speed and climb rate, maybe also rate of roll was more important than pure turning ability.

Juha

ADDITION: One oddity in the Soviet table is LaGG-3 Series 28, Finnish experiences were that LaGG-3s were not good turners, I exclude the lightened Series 66 here, it's pity that Finnish seems to have made a proper tests only with their war booty LG-1, which was a series 4 plane and so a worst case scenario, results at best were 23 sec at 2000m, usually 25sec, with a speed loss of 40km/h, so one must remember that if speed was allowed to drop then according to FAF tests a 109G-2 turned 360deg in 18 sec at 1000m when speed dropped from 450km/h to 330km/h, so with markedly bigger speed loss. Of course one must remember that FAF used warbooty plane in tests but a one which they also used operationally. LG-1 flew 25 combat sorties and got the only LG kill in FAF service, a Soviet LaGG-3 on 16 Feb 44

It would have been nice if Finns had also made thorough tests with warbooty LG-3, which was a Series 35 plane.

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Thank you!!

from the soviet LaGG-3 flight manual, translated in spanish

VI. PILOTAJE



Virajes



98. Gire inclinando el aparato 60—70 ° y hágalo a 320 km/h (según indicador).



Antes de la realización de los virajes, en vuelo horizontal es necesario balancear el avión mediante compensadores. El movimiento coordinado de pedales y palanca le hará girar. A medida que va aumentando el alabeo, incrementar los gases de tal forma que cuando el alabeo llegue a 60-70º, el gas tiene que estar puesto a máxima potencia.



A la salida del viraje reduzca gases a normal. En los giros a izquierda el aparato tiende a aumentar el alabeo; es fácil compensarlo con la palanca. En giros a la derecha el aparato hunde el morro, lo que se compensa fácilmente con pedal izquierdo.



El aparato es estable en los virajes. Al tirar en exceso de la palanca el aparato pierde estabilidad transversal y tiende a salir del viraje. Si se continúa tirando de la palanca, el aparato entra en una barrena.



Un viraje completo con 60—70 ° de alabeo precisa 22—23 segundos.


60-70° inclination, 320 instrumental speed, 22-23 secunds. Surpisingly with both M 1O5P and 1O5PF engines. Not very accurate...

In fact with 120-140 M-105PF extra HP, the LaGG-3 performs much better!

Regards

VG 33

VG-33 said:

VG-33



Not that small, 18 (P-40C) against 20,5 ( 109F) is a confotable 14% advantage. Now, was the Bf 109F 14% faster?

Regards

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I believe the 109F4 is 15.2% faster than a P40E.

The difference in level speed between a 109G6 and and P40N would be about 9.6%.
The G6 could climb to 20,000 ft in 6.5 minutes, while the P40N took 9 minutes. Thats a considerable advantage for the 109.

VG-33 said:

Hello



Listen Soren, i might be not as good in engish as you, and assume it. But you use improper worlds:

- you'v got the belief that 109 E/F turns better than P-40C/E.
- I shaw you by concrete soviet test figures, that physically P-40 turns better than Bf 109, even in very favourable test conditions for the german plane.

Can you make us the mathematical demonstration that Bf 109 turns better?

VG-33

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Yes I can quite easily demonstrate why the Bf-109 in reality turns better than the P-40, I've done it before. But if you want an even more thurough mathematical demonstration then you need but look at Hohun's tables, he takes into account even more variables than I do and he firmly proves the fact that the Bf-109 is a better turnfighter than the P-40. To deny that would be to deny the very rules of physics we live under!

So like I said, believe in what you wish VG-33, but I prefer to believe in what is physically possible. If you wish to trust blindly in 60 year old data which no doubt was under heavy influence of bias and other insecurity factors, which is what Juha seems to prefer, then be my guest, but I don't have to.

PS: After you've read Hohun's documentation then feel free to let me know if you still wish me to perform my by comparison rather simple little demonstration.

Soren said:

Yes I can quite easily demonstrate why the Bf-109 in reality turns better than the P-40, I've done it before.

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Where? Can you give me a link, please? Sorry j'm new on that forum...

But if you want an even more thurough mathematical demonstration then you need but look at Hohun's tables, he takes into account even more variables than I do and he firmly proves the fact that the Bf-109 is a better turnfighter than the P-40.

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I will, just a little later

Best regards

VG-33

Surely
measuring how well or fast a fighter makes a turn in a controlled test environment is good science but sadly lacking in everyday application; as the turn inevitably becomes a turn-fight, both fighters are bleeding energy, it will get to the point where the P-40 is beginning to feel its extra ton or so in weight over the Bf109. This would logically suggest than the P-40 would need to nail the Bf109 within the first turn or very shortly thereafter, assuming that the better turn radius of the P-40 is actually the case.

I chose ME-109...But after reading this article, I might have decided P-40.I got this from wikipedia.

"The P-40 had good agility, especially at high speed and medium to low altitude. It was one of the tightest-turning monoplane fighters of the war,[9] although at lower speeds it could not out-turn the extremely manoeuvrable Japanese fighters such as the A6M Zero and Nakajima Ki-43 "Oscar".[6]

Allison V-1710 engines produced about 1,040 hp (780 kW) at sea level and at 14,000 ft (4,300 m): not powerful by the standards of the time, and the early P-40's speed was average. (The later versions with 1,200 hp (890 kW) Allisons were more capable, as were the Packard Merlin-engined P-40F/L series.) Its climb performance was fair to poor, depending on the subtype.[6] Dive acceleration was good and dive speed was excellent.[6] The highest-scoring P-40 ace, Clive Caldwell (RAAF), who scored 22 of his 28½ kills in the P-40, said the type had "almost no vices", although "it was a little difficult to control in terminal velocity".[10] Caldwell said that the P-40 was "faster downhill than almost any other aeroplane with a propeller." However, the single-stage, single-speed supercharger meant that it could not compete with contemporary aircraft as a high-altitude fighter.

The P-40 tolerated harsh conditions in the widest possible variety of climates. It was a semi-modular design and thus easy to maintain in the field. It lacked innovations of the time, such as boosted ailerons or automatic leading edge slats, but it had a strong structure including a five-spar wing, which enabled P-40s to survive some mid-air collisions: both accidental impacts and intentional ramming attacks against enemy aircraft were occasionally recorded as victories by the Desert Air Force and Soviet Air Forces.[11] Caldwell said P-40s "would take a tremendous amount of punishment -violent aerobatics as well as enemy action."[12]


Evidence of the P-40's durability: in 1944 F/O T. R. Jacklin (pictured) flew this No. 75 Squadron RAAF P-40N-5 more than 200 mi (320 km) after the loss of the port aileron and 25% of its wing area. The fighter was repaired and served out the war.It had armour around the engine and the cockpit, which enabled it to withstand considerable damage. This was one of the characteristics that allowed Allied pilots in Asia and the Pacific to attack Japanese fighters head on, rather than try to out-turn and out-climb their opponents. Late-model P-40s were regarded as well armored.

Caldwell said that he found the P-40C Tomahawk's armament of two .50 in (12.7 mm) machine guns firing through the prop and two .303 Browning machine guns in each wing to be inadequate.[12] This was rectified with the P-40E Kittyhawk, which had three .50 in (12.7 mm) guns in each wing, although Caldwell preferred the Tomahawk in other respects.

Operational range was good by early war standards, and was almost double that of the Supermarine Spitfire or Messerschmitt Bf 109, although it was inferior to the A6M Zero, Ki-43, P-38 and P-51.

Visibility was adequate, although hampered by an overly complex frame and completely blocked to the rear in early models due to the raised turtledeck. Poor ground visibility and the relatively narrow landing gear track led to many losses due to accidents on the ground.[6]"

VG-33 said:

Big your pardon? I red all the treads from n°1 to his n° 65 and saw no explanation about them. May I have missed something.

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If you really would have read the thread you would have seen post #130 (http://www.ww2aircraft.net/forum/aviation/bf-109-vs-p-40-a-16213-9.html#post503531) where he posted a pdf with his methodes.

Hello VG-33
Thanks a lot for the text of LaGG-3 manual.
Much appreciated

I think that also the Finnish numbers I gave in message #236 for LaGG-3 are IAS, ie indicated, even if that is not stated in the test report.

Hello Cromwell
I agree with Kurfürst, RAF lost almost 959 a/c from direct result of the campaign in France May-June 40, Fighting was very intensive.

Soren
If you mind to explain why you think that Finnish AF Bf 109G-2 tests were Quote:" was under heavy influence of bias and other insecurity factors", because their results were in line of Soviet tests?

And how you think a Bf 109G-2 and a G-2/R6 could achieve max speeds of 666 and 665km/h , again quote from your message: "...secondly the other one had crash landed and was so badly damaged that a new wing had to be made for it by Russian engineers. And third, the engines were not running at full power as the Soviets didn't have the proper fuel."?

Juha

Hello VG-33
Finns tested turning ability of LG-1, the series 4 LaGG-3, also with cruising speed and power

360deg turn

At 2000m entry speed 350km/h, end speed 310km/h, time 26sec
At 4000m___________340______________300_________26
At 6000m___________270______________230_________27sec

And I forgot to mention that at the time of the tests Finns had modified LG-1 wings with slots.

Juha

Good point Colin. I think that gets lost in all the numbers.