(Bob M.) wrote in message . com...
I have read that the usefulness of the Bell P-39 was greatly decreased
by certain decisions made by the USAAF before it went into production
in the 1930s. Chief among these was the deletion of the
turbosupercharger, but the shortening of the wings also had an effect.
The question is, just how much more effective would this plane have
been had these changes not been made? Would it have a much greater
climb rate and been more effective at high altitudes? Or would it
still have been pretty much of a bust as a fighter/interceptor?

Turbosuperchargers were in scarce supply until production was ramped
up during WW2. Even then, prority was given to the 4 engined bombers
and more promising fighters such as the P-47 and P-38. Also, the early
turbosuperchargers suffered control and reliability issues. The fact
that the turbosupercharger was never reinstated in the P-39, even when
the plane's limitations became conspicuous, would seem to confirm
these issues. Subsequent attempts to improve altitude performance
concentrated on the versions of the Allison V12 with a two stage
mechanically driven supercharger. The two stage Allison was adopted
for the P-63, a design similar in comcept to the P-39, but appreciably
more sophisticated.

Rober Inkol