A single-seater helicopter that is made by a 20-year-old farmer from central China with a pile of steel pipe, some Elm wood and a 150cc scooter engine. Using what he remembered from his high-school physics and information on the Internet, Wu Zhongyuan built the helicopter by carving its rotor blades out of Elm wood and then reinforcing the copter's frame with used steel pipes. He then installed a motorcycle engine to power the copter — all for a budget around $1,600. Wu claimed the 'copter could get as high as 2,600 feet. However, the local government later halted Wu's flight out of safety concerns.