Evaluation on P-39 maximun speeds!

[Tales Carneiro]

I would like some evaluation about P-39 maximun speeds at diferent altitude!

I found in the fórum a flight test on the aircraft but no references about maximum speeds.

[Juha]

Hello You can find speed and climb graphs for
P-39D at http://www.wwiiaircraftperformance.o...7320-chart.jpg
P-39N at http://www.wwiiaircraftperformance.o...comp-chart.jpg

Checked from Wagner's American Combat A/C and it gives same speed for N. N had rather good performance at low and mid-altitudes.

Juha

[Micdrow]

Originally Posted by Tales Carneiro

I would like some evaluation about P-39 maximun speeds at diferent altitude!

I found in the fórum a flight test on the aircraft but no references about maximum speeds.

I added another document here today that you may find interesting also.

http://www.ww2aircraft.net/forum/fli...read-5482.html (P-39 Performance Thread)

[Tales Carneiro]

Sounds interesting how the two source disagree a lot with respect to maximum airspeeds.

What is the source of the first? And the second?

How about evaluations of the manufacturer itself, Bell aircrafts?

[comiso90]

Were the Russians able to perform any modifications that enhanced performance? Certainly they adopted tactics to exploit the strengths but did they do any airframe or mechanical tweaking to wrench performance from the P-39?

[Juha]

Tales
those in Mike William's site are are based on tests flights. Anyway N should be faster than early Qs or any Q with underwing mg gondolas

Comiso
usually Russians removed the wing armament

Juha

[comiso90]

Originally Posted by Juha

Comiso
usually Russians removed the wing armament

Juha

to what effect? better low altitude handling? increased load?

.

[kool kitty89]

Reduced drag on the P-39Q which had a pod/gondola mounted .50 under each wing. In this configuration (and possibly with a 4-blade prop of later Q models) I belive this was the fastest production Airacobra approaching 400 mph at ~10-11,000 ft.

I'm not sure about removing the 4x .30's internal mounted in the wings on earlier models.

Those speed figures may be exaggerated though as the P-40F seems much too fast compared to other figures I've seen (though Curtiss testing figures are reputed to be exaggerated). The first listed P-40F figure seems realistic, but second one with the short dashed line at 8,500 lbs seems a bit fast with an unusually high critical altitude. (with 380 mph at 22,500 ft)

That also seems high for the P-39D, for the N/Q (and some M's) this seems realistic, but not for the P-39D.

[Juha]

Comiso
Russians wanted lighten the plane.

Tales
one explanation is that the lower figures are flown with military power (1200hp for N and Q) and the higher with WEP (1420 hp for N and Q) permitted max 5 min in time.

KK
many Soviet pilots removed wing guns also from earlier models, idea was to make a/c lighter. And they didn't think highly on .300 mgs thought them rather useless, especially those in wings. Germans. Soviets and Finns wanted closely grouped armament.

Juha

[Tales Carneiro]

Thanks for explanation. What is the armament of this russian modified a/c?

30mm (37mm?) cannon and two mg's?

However M Willians do not present FW 190 and Zero versions. Zero didnt have much speed, but FW! What is the FW in this comparison?

[Juha]

Hello Tales
Russian P-39s, when wing armament was removed they had 1*37mm + 2*12,7mm.

On performance of Zero and 190
Now it is always better to look info from user country for a/c performance, many times the info based on captured a/c was a bit unreliable.

Juha

[Rapecq]

Hello

Does anyone has anything more specific then those chart:
http://www.wwiiaircraftperformance.o...7320-chart.jpg

Well, for me this chart in terms of speed iis awfully unclear - so many similiar looking lines.

Regards