The aircraft was first conceived by Ilyushin in 1967 to meet a requirement for a freighter able to carry a payload of 40 tons (88,000 lb) over a range of 5,000 km (2,700 nmi; 3,100 mi) in less than six hours, able to operate from short and unprepared airstrips, and capable of coping with the worst weather conditions likely to be experienced in Siberia and the Soviet Union's Arctic regions. It was intended to replace the Antonov An-12. Another intended version was a double-decked 250-passenger airliner but that project was cancelled. The Il-76 first flew in March 1971.[5]