Bell P-39 Airacobra

The Bell P-39 Airacobra was a single-engine fighter that Bell Aircraft built for the United States Army Air Forces during World War II. Its unusual layout put the Allison engine in the middle of the fuselage behind the pilot, driving the propeller in the nose through a long shaft, and it was the first fighter fitted with a tricycle undercarriage. The design began under a 1937 Army requirement for a high-altitude interceptor, and the XP-39 prototype first flew on 6 April 1938. Without an efficient turbo-supercharger it performed poorly at altitude, so the Royal Air Force rejected it for use over western Europe, but the Soviet Union, where most air combat took place at medium and low altitudes, took thousands through Lend-Lease. Production ended in August 1944 after 9,558 had been built.