SHOULD the P39 have been able to handle the Zero? Was it training or performance?

[pinsog]

Three comments. First the mixed armament thing, trying to deal with two different trajectories when deflection shooting. That is why I suggested an all 50 cal armament package. Second, history tells us the most US versions of the 20mm Hispano cannon had almost as much trouble with jams/un-reliability early in the war as the 37mm. Another point for staying with just Browning 50 cal guns. Finally, as far as I know, during WW2 'wet wings' implied unprotected fuel tanks. I am suggesting adding self-sealing rubber bag tanks as per other American fighters.

I am a big fan of the 50 so an all 50 arrangement, especially against the Japanese, with their limited protection, would be fine with me. Agreed on the self sealing wing tanks, when I said wet wings I meant self sealing wing tanks, OR standard wing tanks and a CO2 purge system might work just as well and provide more fuel and still provide good protection.

 

[davebender]

history tells us the most US versions of the 20mm Hispano cannon had almost as much trouble with jams/un-reliability early in the war as the 37mm

Problem is real world people don't get the benefit of hindsight.

If U.S. 20mm cannon had worked as advertised it would have been far superior to .50cal MG. Which btw also had problems with jams in early war P-40s. I wouldn't be surprised if .50cal MGs in P-39 jammed also.

If all your weapons tend to jam it's understandable that early war P-39s would have a tough time in combat.

 

[pinsog]

Problem is real world people don't get the benefit of hindsight.

If U.S. 20mm cannon had worked as advertised it would have been far superior to .50cal MG. Which btw also had problems with jams in early war P-40s. I wouldn't be surprised if .50cal MGs in P-39 jammed also.

If all your weapons tend to jam it's understandable that early war P-39s would have a tough time in combat.

Wasn't the P38 20mm much more reliable than the other 20mm mounted on other US aircraft?

 

[Shortround6]

Not sure about the P-39 but the P-38 20mm was pretty good. Gun was mounted in a heavy cradle. Early P-39s had terrible trouble with the 37mm, it often fired just two rounds and jammed, solved by altering the ejection port/chute. Early 20mm didn't have to very good to beat that.
Early .50 cal guns were very slow firing when synchronized, between 450-500rpm, I am not sure if they ever got faster.

 

[CobberKane]

That's fine - employ the P-39 at at an altitude where it works best, say 10,000 feet. All we have do do now is assume that the Japanese fighters won't be so unsporting as to use their superior altitude performance to position themselves for an attack from above.
If the P-39 was going to make an impression against the Zero or Oscar in the kind of situations typical of the early to mid PTO it would need to have been able to tackle them at or above 15000 feet, but it couldn't and it didn't. Being a good performer at low altitude isn't much use if the opposition can climb faster, fly higher and has the opportunity to do so. Under those circumstances the superiority in speed and dive don't confer competitiveness, they just give you a chance for escape.
I suggested somewhere else that the two most important performance characteristics in air to air combat are speed and climb/altitude performance, on the grounds that I can't think of any fighter that significantly lacked both of these characteristics relative to the opposition and still proved superior overall, irrespective of other qualities. Compared to the Zero, the P-39 was faster but badly lacking in altitude capability. As covered by Tomo earlier, the tactical situation in the PTO meant that thenJapanese fighters could therefore usually engage from above. The Wildcat was somewhat slower than the zero but like the P-39 it could outlive the Japanese fighters, and it's much better altitude performance gave it the chance of using that advantage offensively as well as defensively.
Like a lot of people, I think the P-39 was a missed opportunity for the USAF. At a time when pretty much all other US single engine fighter designs were sound but uninspired, it was genuinely forward thinking. Pity the same couldn't be said of the Air Force theoreticians who neutered it.

 

[Shortround6]

Like a lot of people, I think the P-39 was a missed opportunity for the USAF. At a time when pretty much all other US single engine fighter designs were sound but uninspired, it was genuinely forward thinking. Pity the same couldn't be said of the Air Force theoreticians who neutered it.

Neutered how?

And if not neutered when would it have entered large scale squadron service?

 

[michaelmaltby]

".... I think the P-39 was a missed opportunity for the USAF. At a time when pretty much all other US single engine fighter designs were sound but uninspired, it was genuinely forward thinking."

Agree.

MM

 

[FLYBOYJ]

That's fine - employ the P-39 at at an altitude where it works best, say 10,000 feet. All we have do do now is assume that the Japanese fighters won't be so unsporting as to use their superior altitude performance to position themselves for an attack from above.
If the P-39 was going to make an impression against the Zero or Oscar in the kind of situations typical of the early to mid PTO it would need to have been able to tackle them at or above 15000 feet, but it couldn't and it didn't. Being a good performer at low altitude isn't much use if the opposition can climb faster, fly higher and has the opportunity to do so. Under those circumstances the superiority in speed and dive don't confer competitiveness, they just give you a chance for escape.
I suggested somewhere else that the two most important performance characteristics in air to air combat are speed and climb/altitude performance, on the grounds that I can't think of any fighter that significantly lacked both of these characteristics relative to the opposition and still proved superior overall, irrespective of other qualities. Compared to the Zero, the P-39 was faster but badly lacking in altitude capability. As covered by Tomo earlier, the tactical situation in the PTO meant that thenJapanese fighters could therefore usually engage from above. The Wildcat was somewhat slower than the zero but like the P-39 it could outlive the Japanese fighters, and it's much better altitude performance gave it the chance of using that advantage offensively as well as defensively.
Like a lot of people, I think the P-39 was a missed opportunity for the USAF. At a time when pretty much all other US single engine fighter designs were sound but uninspired, it was genuinely forward thinking. Pity the same couldn't be said of the Air Force theoreticians who neutered it.

Some US pilots were able to engage the Japanese at altitudes where the P-39 was able to put up a fight. "Buzz" Wagner was one of the first US aces and scrored kills in both P-40 and P-39. He led several low level raids that were quite successful before being sent back to the US with 8 credits. He was later killed in a P-40 crash stateside.

Pittsburgh Post-Gazette - Google News Archive Search

 

[drgondog]

Best guess at what altitude they would be dead even at? Wouldn't the P39 be faster than an F4F even at 20,000 feet?

It might, but the excess power available to the P-39 is probably less and that would reduce climb as well as sustained turn as well as acceleration

 

[drgondog]

That's fine - employ the P-39 at at an altitude where it works best, say 10,000 feet. All we have do do now is assume that the Japanese fighters won't be so unsporting as to use their superior altitude performance to position themselves for an attack from above.

If the P-39 was going to make an impression against the Zero or Oscar in the kind of situations typical of the early to mid PTO it would need to have been able to tackle them at or above 15000 feet, but it couldn't and it didn't. Being a good performer at low altitude isn't much use if the opposition can climb faster, fly higher and has the opportunity to do so. Under those circumstances the superiority in speed and dive don't confer competitiveness, they just give you a chance for escape.
I suggested somewhere else that the two most important performance characteristics in air to air combat are speed and climb/altitude performance, on the grounds that I can't think of any fighter that significantly lacked both of these characteristics relative to the opposition and still proved superior overall, irrespective of other qualities. Compared to the Zero, the P-39 was faster but badly lacking in altitude capability. As covered by Tomo earlier, the tactical situation in the PTO meant that thenJapanese fighters could therefore usually engage from above. The Wildcat was somewhat slower than the zero but like the P-39 it could outlive the Japanese fighters, and it's much better altitude performance gave it the chance of using that advantage offensively as well as defensively.
Like a lot of people, I think the P-39 was a missed opportunity for the USAF. At a time when pretty much all other US single engine fighter designs were sound but uninspired, it was genuinely forward thinking. Pity the same couldn't be said of the Air Force theoreticians who neutered it.

It is hard to argue for the P-39 in PTO, MTO and ETO where its primary opponents could all out perform it with respect to high altitude performance and overall combat agility. The 37mm cannon was the eternal nightmare. It had wicked and often fatal spin characteristics, relatively short range.

In late 1941, if you had been sitting on a USAAF Review Board, why would you single the P-39 as a fighter to invest in for the future when both the P-47 and P-38 were faster, more heavily armed and a much greater performance vs altitude bandwidth.

Had Allison been capable of a two stage supercharger then, the story would be different. The P-63 was much better but too late for USAAF. Only the P-38 and P-63 survived the war with Allisons as the powerplant of choice for US Fighters.

 

[vinnye]

Did they ever try to fit a Merlin into the P39?
It worked quite well in the P51 - so why not the P39?

 

[drgondog]

Major CG issues re-locating 1600 pounds from behind cockpit to in front. Total re-design almost with no common parts.

 

[Shortround6]

Why was the P-39 so zippy at low altitudes on limited power?

Because it was small

Why didn't they fit bigger superchargers, inter-coolers and larger engines in the P-39?

Because it was small

Simple really.

 

[tomo pauk]

To be fair, there were Merlins that were roughly sized as P-39's V-1710 (complete with supercharger), and required no inter-coolers. Made in the USA, never the less.

 

[michaelmaltby]

"... Neutered how?

And if not neutered when would it have entered large scale squadron service?"

The USAAF had no engagements that in any way replicated the totality of the Eastern Front where the Soviets were able to utilize the P-39 as an under 11,000 ' down to the deck dogfighter, supporting Sturmoviks .... but, that said, during Guadalcanal, the P-39 was an effective fire support platform over land and sea. The 20 mm canon from the British rejects and later the 37 mm Olds canon, were good at barge busting. The AC was less vulnerable to ground fire than the P-40 due to the engine location. Range wa less an issue in this theatre, and the idea of accepting that the P-39 was not ever going to be a high altitude interceptor and hence getting on with using the AC for its strengths, seems obvious to me. It was a flawed concept in 1941-42 but by 1944 the Q model was very good and the P-63 took the best and made it better. The Soviets certainly benefitted, and those American who mastered the P-39, like Chuck Yeager, knew it had sass.

MM

 

[michaelmaltby]

".. Only the P-38 and P-63 survived the war with Allisons as the powerplant of choice for US Fighters."

And the Twin Mustang ...

 

[CobberKane]

In late 1941, if you had been sitting on a USAAF Review Board, why would you single the P-39 as a fighter to invest in for the future when both the P-47 and P-38 were faster, more heavily armed and a much greater performance vs altitude bandwidth.

Had Allison been capable of a two stage supercharger then, the story would be different. The P-63 was much better but too late for USAAF. Only the P-38 and P-63 survived the war with Allisons as the powerplant of choice for US Fighters.

That's pretty much what I meant by the P-39 being neutered. The pre-war thinking of the time was that the bomber would always get through, so altitude performance for fighters was not a major concern. If it had been, and if Alison had incentive to develop their engine accordingly, maybe the P-39 would have been available for the PTO in a form that allowed it to use it's speed and dive superiority for something other than running for home. Unfortunately it didn't happen, and and pilots who managed to make effective use of the P-39 against zeros and Oscars were very much in the minority. As noted in a Japanese training manual of the time: "Altitude is worth more than a brave heart."

 

[bobbysocks]

people get sentimental about a plane they like...and wish it could be or could have been upgraded and improved to perform like all the aircraft that had been designed around new ground breaking technology. i am sure somewhere there is a guy sitting and thinking with a few tweeks the kingfisher could have been made into a top notch fighter.

 

[drgondog]

Actually the P-82B was Merlin driven with 1650-9 and 11. Its downfall as a top high performance a/c is when the Sec'y Air Force dictated the Allison -143 and -145 for the P-82E ordered in Dec 1945.

Edgar Schmeud and his team solved the constant backfire issues but Allison wouldn't listen and NAA wasn't able to fire the GM owned Allison.

 

[drgondog]

"... Neutered how?

And if not neutered when would it have entered large scale squadron service?"

The USAAF had no engagements that in any way replicated the totality of the Eastern Front where the Soviets were able to utilize the P-39 as an under 11,000 ' down to the deck dogfighter, supporting Sturmoviks .... but, that said, during Guadalcanal, the P-39 was an effective fire support platform over land and sea. The 20 mm canon from the British rejects and later the 37 mm Olds canon, were good at barge busting. The AC was less vulnerable to ground fire than the P-40 due to the engine location. Range wa less an issue in this theatre, and the idea of accepting that the P-39 was not ever going to be a high altitude interceptor and hence getting on with using the AC for its strengths, seems obvious to me. It was a flawed concept in 1941-42 but by 1944 the Q model was very good and the P-63 took the best and made it better. The Soviets certainly benefitted, and those American who mastered the P-39, like Chuck Yeager, knew it had sass.

MM

Chuck is often quoted as being willing to soldier on in the P-39 - but he didn't mean it for ETO. He would have had his ass handed to him by perhaps inferior pilots had they flown to 109 and 190 strengths rather than try low altitude turning fight. Escorting B-17s at 25000 feet would have resulted in extremely high losses. The Brits figured that out in 1941 and sent all of theirs to USSR.