<Tr> <Th> Number built </Th> <Td> </Td> </Tr> <Tr> <Th> Developed from </Th> <Td> Antonov An - 124 </Td> </Tr> <P> The Antonov An - 225 Mriya (Ukrainian: Антонов Ан - 225 Мрія, lit .' dream' or' inspiration', NATO reporting name: "Cossack") is a strategic airlift cargo aircraft that was designed by the Antonov Design Bureau in the Ukrainian SSR within the Soviet Union during the 1980s . It is powered by six turbofan engines and is the heaviest aircraft ever built, with a maximum takeoff weight of 640 tonnes (710 short tons; 630 long tons). It also has the largest wingspan of any aircraft in operational service . The single example built has the Ukrainian civil registration UR - 82060 . A second airframe with a slightly different configuration was partially built . Its construction was halted in 1994 because of lack of funding and interest, but revived briefly in 2009, bringing it to 60--70% completion . On 30 August 2016, Antonov agreed to complete the second airframe for Aerospace Industry Corporation of China (not to be confused with the Aviation Industry Corporation of China) as a prelude to AICC commencing series production . </P> <P> The Antonov An - 225, initially developed for the task of transporting the Buran spaceplane, was an enlargement of the successful Antonov An - 124 . The first and only An - 225 was completed in 1988 . After successfully fulfilling its Soviet military missions, it was mothballed for eight years . It was then refurbished and re-introduced, and is in commercial operation with Antonov Airlines carrying oversized payloads . The airlifter holds the absolute world records for an airlifted single - item payload of 189,980 kilograms (418,830 pounds), and an airlifted total payload of 253,820 kg (559,580 lb). It has also transported a payload of 247,000 kg (545,000 lb) on a commercial flight . </P>

How many engines does the antonov an 225 cossack have