The Bell P-39 was an unusual fighter at the time, the engine was placed in the center of the aircraft for a good weight-ratio. This was not unique but at the least unusual.

The P-39 Airacobra had a tricycle landing gear, which was the first such gear ever used on a production fighter. The Airacobra battled throughout the world, particularly in the Southwest Pacific, Mediterranean and Russian theaters. Because its engine was not equipped with a supercharger, the P-39 performed best below 17,000 feet (5,200 m) altitude.

 

The P-39 often was used at lower altitudes for such missions as ground strafing. Same with the P-63 Kingcobra, the P-39 aircraft was considered to be the most victorious mass-produced, fixed-wing aircraft manufactured by Bell Aircraft Corporation. Primarily used by the U.S Army Air Force

 

- The prototype XP-39 flew for the first time on April 6th 1938 powered by an Allison V-1710-17 12 Cylinder liquid-cooled engine providing 1150 Hp.

- The next step was the YP-39 of which 13 were produced for service evaluation. The YP-39 was mounted with an 37 mm M4 Cannon, two fuselage mounted 12,7 mm guns and two wing-mounted 7,62 mm guns.

- The initial production model (P-39C) was similar to the YP-39 and 20 were built.

- Adding self sealing fuel-tanks and two additional 7,62 mm machine guns in the wings resulted in the P-39D witch entered service to the USAAC in February 1941.

- The P-39-1 replaced the 37 mm M4 cannon with a 20 mm M1 cannon.

- After that the P-39D-2 replaced the 1150 Hp V-1710-35 with a 1325 Hp V-1710-63 engine.

- There were three examples built with laminar-flow wings (XP-39E)

- The P-39F was basically a P-39D with minor upgrades.

- Only 25 Airacobra’s were built with a 1100 Hp engine (V-1710-59 by Allison) designated P-39J.

- P-39K: was also basically a P-39D-2 but with a different propeller

- P-39L: Also a P-39D-2 only with a different nose-wheel

- In November 1942 the first P-39M began to appear, it had a 1200 Hp V-1710-83 engine.

- P-39N: This was the first Airacobra built in large numbers, it had a 1200 Hp V-1710-85 engine, and 2095 were built.

- The final subtype of the P-39, the P-39Q had the wing-mounted 7,62 mm machine guns deleted, and a 12,7 mm gun mounted beneath each mainplane. The P-39Q was built in the largest numbers, at total of 4905 P-39Q’s left the factories.

 

Totally a number of 9558 P-39 of all types were produced.

Developing Nation:	United States
Manufacturer/designer:	Bell Aircraft Corporation
Task:	Fighter aircraft
First Flight:	XP-39: April 6th 1938
First Delivery:	February 1941: To the 31st Pursuit Group (39th, 40th, and 41st Pursuit Squadrons) based at Selfridge Field, Michigan.
P-39D:
Crew:	1
Wing Span:	10.36 m
Wing Area:	19,79 m²
Length:	9,19 m
Height:	3,60 m
Engine (s):	P-39D: Allison V-1710-35 1,150 hp engine P-39D-2: V-1710-63 (E6)? 1,325 hp engine
Weight empty:	2477 Kg
Max. Take off weight:	4014 Kg
Max. Speed:	539 Kph (1524 m) 579 Kph (4572 m)
Cruise Speed:	483 Kph
Max. Range:	Internal fuel: 724 Km, at 483 Kph and 7620 m
Service ceiling:	9784 m
Weapons:	One 20 mm M1, Engine mounted nose gun Two 7,62 mm wing guns Two fuselage mounted 12,7 mm guns
Extra:	In March of 1941, Bell’s test pilot Vance Breese drove an Airacobra 15,000 feet to pass the final Army Air Corps test. The 39th PS participated in the “Carolina Maneuvers” from September to November of 1941, which was a series of war games during which five different squadrons flew Airacobra’s. The P-39D (along with the P-400) was the first to see combat in US service. A total of 1,767 P-39D built.

Type	Number built/ converted	Remarks
XP-39	1	Prototype P-39
YP-39	13	Improved XP-39; service test aircraft
YP-39A	1 (cv)	YP-39 with new engine; high alt. test only
XP-39B	1 (cv)	XP-39 with new engine; no turbo-supercharger
P-39C	80	P-45 redesignated; 60 became P-39D
P-39D	60 (cv)	Improved P-39C; 4x.30, 2x.50 mgs. and 37mm cn.
P-39D-1	863	Improved P-39D; self-sealing fuel tanks
P-39D-2	1 (cv)	Improved P-39D-1; 158 ordered
XP-39E	3	P-39D-1 with new engine; XP-63 prototype
P-39E	0	Improved P-39D-1; 4,000 ordered
P-39F-1	229	P-39D with aero products propeller
P-39F-2	2 (cv)	P-39F modified for photo reconnaissance
P-39G	0	1,800 ordered, became K, L, M, N models
P-39H	0	Designation not assigned
P-39J	25	Modified P-39D-1; new engine and auto boost
P-39K	210	P-39F with new engine
P-39L	250	Modified P-39K; Curtiss prop. and rocket rails
P-39M	240	Modified P-39L; new engine and prop. gearing chg.
P-39N	2,095	Improved P-39M; new engine
P-39P	0	Designation not assigned
P-39Q	4,905	Improved P-39N; 37mm cn. and four .50-cal. mgs.

All pictures courtesy of Zijde Aviation Photo and Publishing, Marcel van Leeuwen