The sleek P-39 started as an interceptor in April 1938. However, as armored systems began to be added, without any increase in horsepower, its speed (initially 390 mph) and maneuverability rapidly dropped until the P-39 was reclassified as a ground attack plane in 1941. However, the P-39 proved quite capable in that role, especially in Russian hands.
The P-39 introduced several new features to US combat aircraft. First, it used tricycle landing gear instead of the more standard tail-dragger arrangement. Second, to place the engine at the airplane's natural center of gravity it was neccessary to place it behind the pilot, with a 8' shaft to the propellor running under the pilot's legs. Pilots new to the P-39 were quite concerned; it didn't take much to imagine what damage a broken shaft could do whipping around in the cockpit. However, the system proved quite reliable in service, even in crash landings. Some 4,900 P-39Qs were built, with a total of 9,558 of all types. Roughly half went to Russia.
The P-39Q uses 38.25 gallons of aviation fuel per hour.
Variants:
P-39C: Initial Army contract, originally listed as P-45. Drop
wing guns and add two .30-cal MGs in nose. 800 built.
P-39D: Add two .30-cal MGs to each wing. At this point on (April
1941) the P-39 was classified as a ground attack plane.
P-63 Kingcobra: While it looked like a slightly enlarged P-39,
it was very different internally. Over 3000 were built, with some 2,500
being sent to Russia. Top speed 410 mph.
Subassemblies: Medium Fighter Body with Good streamlining +3,
Medium Fighter Wings +2
P&P: 850 kW HP gasoline engine w/aerial propeller (2550
lbs thrust)
Fuel: 105 gallons aviation gasoline in self-sealing fuel tanks
(body and wings)
Occ: 1 NCS
Cargo: 5.5 VSP Body, 0.2 VSP Wings
| Armor | F | R/L | B | T | U |
| Body | 3/7 | 3/7 | 3/7 | 3/7 | 4/20 |
| Wings | 3/7 | 3/7 | 3/7 | 3/7 | 3/7 |
| Wheels | 2/5 | 2/5 | 2/5 | 2/5 | 2/5 |
| Cockpit | 0/+10 | 0/+20 | 0/+30 | 0/+10 | 0/+30 |
Weaponry
Long Aircraft MG/Browning M-2 [RWing:F] (300 rounds)
Long Aircraft MG/Browning M-2 [LWing:F] (300 rounds)
2*Long Aircraft MGs/Browning M-2 [Body:F] (300 rounds each)
37mm Medium Aircraft Cannon/37mmL45 M-4 [Body:F] (30 SAPHE)
500 lb hardpoint [Body:U] (bomb or drop tank)
Equipment
Body: long range radio, environmental controls
Statistics
| Size: 12'x34'x30' | Payload: 1755 lbs | Lwt: 7,700 lbs ( tons) |
| Volume: 200 vsp | Maint.: 44 hours | Price: $20,943 |
HT: 8
HP: 120 [body], 80 [each wing]
| aSpeed: 335 | aAccel: 12 | aDecel: 7 | aMR: 3.5 | aSR: 2 | aDrag: 124 |
| Stall: 81 mph |
Design Notes
Design speed was 320 mph and loaded weight 7,728. 40 rounds of 37mm
ammo were purchased. The historical values have been used. Loaded weight
includes a 500-lb bomb.