The aircraft carrier's design is based on the Soviet Union's Kuznetsov class, as China's first carrier, Liaoning, was constructed from an incomplete Kuznetsov-class vessel and the 001A is a refined version of Liaoning. It is slightly modified and upgraded compared to Liaoning, with improved radar and increased storage capacity for amm unition and fuel, allowing it to carry more aircraft than Liaoning (estimated to be between 30 and 40 jets and helicopters). It measures about 315 metres (1,033 ft) long, with a displacement of about 55,000 tonnes (70,000 loaded).The ship is believed to be powered by conventional oil-fired boilers driving steam turbines.It retains the ski jump takeoff, which limits its air wing to helicopters and Shenyang J-15 fighter jets and could be updated to stealth fighters such as the Shenyang J-31 or the Chengdu J-20; future Chinese carriers are planned to use catapults that allow the launch of heavier aircraft as well as stealth aircraft such as the Shenyang J-31 or the Chengdu J-20.