Most gliders do not have power devices and are heavier than air fixed-wing aircraft. It can be towed by the aircraft, or it can be towed by a winch or a car, and it can also slide from the high slope to the air. In the absence of wind, the glider relies on the weight of its own gravity to gain forward power during the descent flight. This loss height of the non-powered descent flight is called gliding. In updrafts, gliders can fly or rise like eagles, often called soaring. Modern gliders are mainly used for sports, divided into primary gliders and advanced gliders. The former is mainly used for training flights, the latter is mainly used for competitions and performances, and some can also complete a variety of advanced aerial stunts, such as somersaults and spirals. After the 1970s, the suspension glider began to recover on the basis of modern science and technology(improvement of structural materials and improvement of manufacturing processes), attracting a large number of flying enthusiasts. ????