Version overview
XP-39
Prototype with a supercharged Allison V1710-17 engine rated at 1,150 hp.
XP-39A
A prototype that used a non-turbocharged engine.
XP-39B
The non-turbocharged prototype flew 28 hours.
YP-39
Preproduction versions ordered by the Air Force, a new Allison V1710-37 engine rated at 1,090 hp was selected due to a problem with the turbocharged engine. The aircraft was armed with one 37 mm Oldsmobile T-9 cannon, two 12.7 mm machine guns, and two 7.62 mm machine guns in the nose. The pilot's seat was armored.
P-39C
Same as the YP-39 production versions.
P-39D
Improved armament, two 7.62 mm machine guns added.
XP-39E
Originally envisaged with an inline Continental engine, later tests "chopped off" wingtips, a direct predecessor of the P-63.
P-400
British P-39, 30mm cannon replaced by the British Hispano M1 20mm cannon and machine guns replaced by Browning 7.7mm type. After a short service in the RAF, they were sent to the USSR. [article]
P-39F
Small changes were made, the biggest change was in the exhaust manifold, there were 12 exhaust ports on each side.
P-39J
The J version was created by installing the new 1100 hp Allison V-1710-59 (E-12) engine in the last 25 units of the F version.
P-39K, P-39L, P-39M, P-39N
Very similar versions, difference in engines, propellers and small details used.
P-39Q
New Allison V1710-85 engine with 1,450 hp, two 12.7 mm machine guns were relocated to containers under the wing instead of the 7.62 mm machine guns located in the wings. Most of these aircraft were sent to the USSR.
XFL-1 Airabonita
Prototype of the naval version.
XTDL-1 / XF2L-1K
Two P-39Q taken over by the Navy and used as flying targets.
P-63 Kingcobra
A direct successor to the P-39.