 Approximately 60 countries over four continents have flown the MiG-21, and it still serves many nations six decades after its maiden flight.It made aviation records, became the most-produced supersonic jet aircraft in aviation history, the most-produced combat aircraft since the Korean War and previously the longest production run of a combat aircraft (now exceeded by both the McDonnell Douglas F-15 Eagle and General Dynamics F-16 Fighting Falcon).The MiG-21 jet fighter was a continuation of Soviet jet fighters, starting with the subsonic MiG-15 and MiG-17, and the supersonic MiG-19.