5 decal variants:
1. Airacobra I, AH 601, No.601 sqn. RAF, S/L E.J. Gracie, August 1941
2. P-400, 2.GSAP, Winter 1942/43
3. P-400 s/n 311, OK-L of Forsa Aerea Portugesa, June 1943
4. P-39 F, A53-6, 83 Squadron RAAF
5. Airacobra I, AH 574, used to deck landing trials by Royal Navy
The P-39 was used with great success by the Soviet Air Force, which scored the highest number of kills per pilot attributed to any U.S. fighter type. Other major users of the type include the Free French, the Royal Air Force, the United States Army Air Forces, and the Italian Co-Belligerent Air Force. Designed by Bell Aircraft, it had an innovative layout, with the engine installed in the center fuselage, behind the pilot, and driving a tractor propeller via a long shaft. It was also the first fighter fitted with a tricycle undercarriage. Although its mid-engine placement was innovative, the P-39 design was handicapped by the absence of an efficient turbo-supercharger, limiting it to low-altitude work.