claidemore
Senior Airman
It's interesting that the Free French were delivered P63s in 1945, and they would definately have been earmarked for use against Germany.
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VG:33 - " ... Viktor Koulikov, P-39 and P-63 in USSR, Avions N°90, Sept 2000.... "
A link would be nice.
MM
What year was this?At this time first P-63 entered into the 7th fighter division VVS of Pacific Ocean fleet. By August 9, when started war with Japan, division had 10 "Kingcobras". About twenty arrived already in the course of military operations, until August 31. They assumed no participation in the operations against the Japanese.
Unfortunately, only in russian (maybe with google translater...)
P-63 ????????? ? ????????? ?????
regards
P-63 is mentioned on page 7 of this document:Why there is no mention of P-63's in L.L. documents?
Aircraft production in the Soviet Ujnion had long since rebounded from th devastating losses suffered in the opening months of the war. Soviet aircraft factories were now in high gear turning out 42,000 airplanes of all types in 1944: a production rate that was fully capable of meeting at least the fighter requirements of the Red Air Force. Even so, the SPC requested continued fighter plane deliveries aimed at rebuilding and reequipping depleted fighter units in the Soviet Far East in anticipation of war against Japan. The majority of P-63 Kingcobras were diverted to this region.
Going by "Vee's for Victory" by Daniel Whitney there were several reasons for deleting the Turbo from the P-39. Not the least of which seems to be that with the original installation the Airplane couldn't come close to the performance estimites or guarantees. Bell was off by about 10% on the weight of the UNARMED plane and off by at least that much in the speed. The intercooler installation seems to have been really bad. It not only had high drag but didn't work very well. In the interest of light weight it had been kept small but the result was that it didn't cool the intake charge very well. While most American intercoolers tried to remove 50% of the heat of compression between the two stages the XP-39 was only managing about 25% during high speed flight and 12% during climb. This ment much more danger of detonation and ment that full power or boost could not be used thus limiting performance of the aircraft. NACA estimated after installing the XP-39 in their full sized windtunnel that a single stage "altitude rated" engine would provide about 30mph more speed than the turbo engine up to about 13-14,000ft. This is after NACA did a clean-up that added 40+mph to the speed of the plane. the Turbo version wasn't expected to show ANY advantage in speed until over 19,000ft had been reached. And it was still about 10mph below the Guarantee speed. Once the requirement changed from 400mph at 20,000ft to 400mph at 15,000 the turbo was really out of the running. The small size of the P-39 ment that installing a larger intercooler setup was almost out of the question.
Please remember that the Early P-38s used the leading edges of the outer wings as inter-coolers and that some models of the P-38 had difficulty in using full power because while these leading edge intercoolers worked well enough with 1150HP engines they were not big enough to handle the airflow of 1300-1425HP engines.
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Any insights on why, after these changes were made and the plane fielded, the P-39 was so hated by the Americans but loved by the Soviets?
As this post started, the P-39 P-40 both had single-stage supercharged Allison V-1710's.
Did the P-39 really underperform compared to the P-39?
The P-40N in the above graph is the untralight early N that only weighed 7600# and reverted to the normal weight for production. So production P-40Ns would be slower than this one.Just a few comments on this excellent thread.
Turbo was deleted from the P-39 in order to get it into production faster. Contemporary P-38 did not enter combat until Dec '42. P-39D was in production in late '41. Notwithstanding, the turbo instal in the P-39 would never work dependably, radiator ducts (coolant, oil and intercooler) were not adjustable meaning too much air at low power and not enough at high power. Also Allison promised more HP was coming with higher supercharger ratios or a mechanical second stage so turbo was deleted.
When comparing the P-39 and P-40 please remember the P-40 was substantially heavier (7650 vs 8400) so with the same engine and propeller the P-39 was faster and much better climb/ceiling. No way out of it.
Russian P-39s performed better because they were lighter than western P-39s because they deleted the 4x.30caliber MGs in the wings and the IFF radio. They thought the light .30caliber MGs were worthless and plenty firepower was left with the 37mm cannon and 2x.50caliber MGs. Saved about 300# (200# for .30caliberMGs and 100# for IFF radio). Russians lightened the P-40 also by deleting 2 of the 6 .50caliber MGs.
Eastern front was fought at lower altitudes than western front (no turbocharged B-17s and B-24s) but that does not explain the P-39s success in that theater. P-39N/Q was competitive with the Luftwaffe at all altitudes or they could not have had the success they had. Altitude was everything in WWII, without it you were a dead duck.
A chart from wwiiaircraftperformance showing speeds for P-39N and P-40N is attached for reference.View attachment 490796