The P-39 Airacobra was the first fighter in the world to have a tricycle undercarriage and to have the engine mounted mid-fuselage behind the pilot. It had rather a troubled beginning because it had been designed as a fighter for the western European theater of operations where it turned out to be completely unsuitable for the role.
Its hours of glory were in the Pacific where it was sent in an emergency to counter the Japanese advance, or in the hands of its Russian pilots, the USSR alone receiving almost half of those produced under Lend-Lease.
The P- 63 Kingcobra, the last avatar of the controversial Airacobra family, with different wings and engine wasn't any more successful in the United States, and two thirds of the machines produced up until 1945 were also assigned to the Soviet Union. 300 examples were supplied to France which used them for its operations in Indochina at the beginning of the fifties.