Bf-109 vs P-40
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FLYBOYJ
"THE GREAT GAZOO"
It's the amount of pressure in the intake manifold measured in inches of Mercury.
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
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
Not that small, 18 (P-40C) against 20,5 ( 109F) is a confotable 14% advantage. Now, was the Bf 109F 14% faster?
Regards
Not that small, 18 (P-40C) against 20,5 ( 109F) is a confotable 14% advantage. Now, was the Bf 109F 14% faster?
Regards
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.
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.
Kurfürst
Staff Sergeant
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.
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
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claidemore
Senior Airman
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.
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.
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Where? Can you give me a link, please? Sorry j'm new on that forum...
I will, just a little later
Best regards
VG-33
Colin1
Senior Master Sergeant
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.
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.
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Doughboy
Staff Sergeant
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]"
"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]"
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.
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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
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
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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
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
Njaco
The Pop-Tart Whisperer
Good point Colin. I think that gets lost in all the numbers.
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