French P-39Q 44-3172 “White 9” of the GC II/6
The “Q” model of the P-39, which had 4,905 units produced, featured the same engine as the P-39N but with modified armament. The 0.30 inch machine-guns were replaced with 0.50 inch machine-guns in a gondola mounted under each wing, with each gondola holding 300 rounds of ammunition. The P-39Q-21-BE, Q-25-BE, and Q-30-BE were exceptions, as they did not have these gondolas. Additionally, there were some minor differences between the various blocks. For example, the P-39Q-1-BE had a V-1710-35 engine that produced 1,150 horsepower; the P-39Q-5-BE had ten wing tanks instead of eight, with a capacity of 416 liters (110 US gallons); the P-39Q-10-BE had its full wing fuel capacity restored, a new microphone, AN-M14 grenades, and modified armor protection; and the P-39Q-15 had new electric circuits, a new oxygen system, and flame dampers on the wing guns. The P-39Q-20-BE was identical to the P-39Q-15 but featured improved armor. The P-39Q-21-BE and Q25-BE could be recognized by their four-blade 3.53 m (11 ft 7 in) Aeroproduct propellers, while the P-39Q-30-BEs were identical to the P-39Q-25-BEs but featured three-blade propellers.
A significant number of P-39Q aircraft were modified for ground attack and tactical reconnaissance missions, with five P-39Q-1-BEs transformed into P-39Q-2-BEs, 148 P-39Q-5-BEs transformed into P-39Q-6-BEs, and eight P-39Q-10-BEs transformed into P-39Q-11-BEs. Additionally, a few P-39Q-20-BEs were converted into two-seat unarmed trainers known as the P-39Q-22-BE. Two aircraft with serial numbers 42-19976 and 42-20807 were transferred to the US Navy to be used as drones, designated XTDL-1 and later XF2L-1K.