The McDonnell Douglas F-15 Eagle is an American twin-engine fighter and attack aircraft, the first flight of which took place on July 27, 1972. The F-15 aircraft is the result of the experience gained from air combat over Vietnam, and is also the USAAF's response to the Soviet Mig-23 and Mig-25 fighters. It was created as part of the FX (Fighter Experimental) project, in which the winner was McDonnell-Douglas in 1969.