Bell P-39J Airacobra

Last revised June 4, 2020

25 P-39Ds were fitted with the 1100 hp V-1710-59 engine with automatic boost control and were redesignated P-39J. Serials were 41-7053/7056 and 41-7059/7079. They differed from the D in having a different engine, the 1100 hp V-1710-59 (E12) with an automatic manifold pressure regulator. At this stage of the war, the production block system of subdividing model changes was not yet in effect, and relatively minor changes brought about letter (series) changes in the model. For example, in the Model P-39, minor changes in the D series resulted in the F, G, K, L, M, and N series rather than new blocks of the D.


  1. War Planes of the Second World War, Fighters, Volume Four, William Green, Doubleday, 1964.

  2. The American Fighter, Enzo Anguluci and Peter Bowers, Orion Books, 1987.

  3. United States Military Aircraft since 1909, Gordon Swanborough and Peter M. Bowers, Smithsonian Institution Press, 1989.

  4. P-39 Airacobra in Action, Ernie MCDowell, Squadron/Signal Publications, 1980

  5. The Calamitous 'Cobra, Air Enthusiast, August 1971.

  6. Airacobra Advantage: The Flying Cannon, Rick Mitchell, Pictorial Histories Publishing Company, Missoula, Montana

  7. Bell Cobra Variants, Robert F. Dorr, Wings of Fame, Vol 10, AirTime Publishing , Inc., 1998.

  8. E-mail from Phil Marchese on production block system.