The McDonnell Douglas F-15 Eagle is an American twin-engine, all-weather tactical fighter aircraft designed by McDonnell Douglas (now part of Boeing). The Eagle first flew in July 1972 and entered service in 1976. It is among the most successful modern fighters, with over 100 victories and no losses in aerial combat, with the majority of the kills by the Israeli Air Force.The aircraft design proved flexible enough that an improved all-weather strike derivative, the F-15E Strike Eagle, was later developed, entered service in 1989 and has been exported to several nations.