Helicopters and other aircraft the most essential distinction lies in its tilt-rotor system.
直升机与其他航空飞行器最本质的区别就在于它的旋翼系统。
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Rather than use either a spherical or a cigar-shaped aerostat, as the gas-filled envelope of a lighter-than-aircraft is known, Skylifter has developed a discus-shaped one.