Bell P-63 Kingcobra

The Bell P-63 Kingcobra was an American single-engine fighter that Bell Aircraft developed during World War II from the P-39 Airacobra, incorporating suggestions from P-39 pilots and proving superior to its predecessor in virtually all respects. It followed the experimental XP-39E, and the first XP-63 prototype flew on 7 December 1942 with an Allison V-1710 engine. The United States Army Air Forces did not accept it for combat use, but the Soviet Air Force, the most prolific user of the P-39, received 2,397 of the 3,303 production aircraft under Lend-Lease and found it a successful fighter. Many served in the United States as RP-63 Pinball manned target aircraft, and surviving examples were later redesignated QF-63.