The Antonov An-124 Ruslan (Ukrainian: Антонов Ан-124 Руслан, lit. 'Ruslan'; NATO reporting name: Condor) is a large, strategic airlift, four-engined aircraft that was designed in the 1980s by the Antonov design bureau in the Ukrainian SSR, then part of the Soviet Union (USSR). Until the Boeing 747-8F, the An-124 was, for thirty years, the world's heaviest gross weight production cargo airplane and second heaviest operating cargo aircraft, behind the one-off Antonov An-225 Mriya (a greatly enlarged design based on the An-124). The An-124 remains the largest military transport aircraft in current service. The lead designer of the An-124 (and the An-225) was Viktor Tolmachev.