(from the article `airplane`) Unpowered manned heavier-than-air vehicles must be launched to obtain lift. These include hang gliders, gliders, and sailplanes.sport of flying in lightweight unpowered aircraft which can be carried by the pilot. Takeoff is usually achieved by launching into the air from a ... ...are also launched by shock-... Found on http://www.britannica.com/eb/a-z/h/13