Hang gliding is an air sport or recreational activity in which a pilot flies a light, non-motorised foot-launched heavier-than-air aircraft called a hang glider. Most modern hang gliders are made of an aluminium alloy or composite frame covered with synthetic sailcloth to form a wing. Typically the pilot is in a harness suspended from the airframe, and controls the aircraft by shifting body weight in opposition to a control frame.
Early hang gliders had a low lift-to-drag ratio, so pilots were restricted to gliding down small hills. By the 1980s this ratio significantly improved, and since then pilots can soar for hours, gain thousands of feet of altitude in thermal updrafts, perform aerobatics, and glide cross-country for hundreds of kilometres. The Fédération Aéronautique Internationale and national airspace governing organisations control some regulatory aspects of hang gliding. Obtaining the safety benefits of being instructed is highly recommended.
In most hang gliders, the pilot is ensconced in a harness suspended from the airframe, and exercises control by shifting body weight in opposition to a stationary control frame, also known as triangle control frame, control bar or base bar. This bar is usually pulled to allow for greater speed. Either end of the control bar is attached to an upright pipe, where both extend and are connected to the main body of the glider. This creates the shape of a triangle or 'A-frame'. In many of these configurations additional wheels or other equipment can be suspended from the bottom bar or rod ends.