The Mikoyan-Gurevich MiG-21 is a supersonic jet fighter aircraft,designed by the Mikoyan-Gurevich Design Bureau in the Soviet Union. Early versions are considered second-generation jet fighters, while later versions are considered to be third-generation jet fighters. Some 50 countries over four continents have flown the MiG-21, and it still serves many nations a half-century after its maiden flight. The fighter made aviation records. At least by name, it is the most-produced supersonic jet aircraft in aviation history and the most-produced combat aircraft since the Korean War, and it had the longest production run of a combat aircraft. The MiG-21 was exported widely and continues to be used. The aircraft's simple controls, engine, weapons, and avionics were typical of Soviet-era military designs. The use of a tail with the delta wing aids stability and control at the extremes of the flight envelope, enhancing safety for lower-skilled pilots;this in turn enhanced its marketability in exports to developing countries with limited training programs and restricted pilot pools. .