Hang Gliding
Hang Gliding is both a recreational and competitive sport. There are two classes of hang gliders. The first is a flexible wing glider, which has it's flight controlled by a wing changing shape as the pilot shifts their weight. The second type of hang glider is a rigid wing hang glider, which is where the flight is contolled by spoilers, typically on top of the wing. The modern design of hang gliding was influenced by NASA technician Francis Rogallo in the late 1940s with his invention of the Flexkite. Other development centered on several Australian designs. Today there are several manufactures, such as Aeros, Avian, and Speedwings.
One of the most important parts of hang gliding is getting into the air. There are several launch techniques one can use, including foot-launching from a hill, tow-launching from a ground-based toe system, aerotowing behind another powered aircraft, and powered harnesses. In addition to this, more exotic launch techniques have been successful, such as very high altitude launches from hot-air balloons. In flight, conditions can either be soarable or not soarable. Not soarable conditions can also be referred to as "sled runs" . A soarable flight can be obtained by riding on thermal currents, which are caused by solar heating of surface air, or ridge lift, which is caused by wind rising over geographical features. The flights that are powered by ridge lift are confined to the viciinty of the ridge (mountainous region) or coastol cliff. Where as thermal flights can extend over great distances and reach thousands of feet in altitude over mountains or flatlands.
Hang gliding has been considered a dangerous sport, due to the fact that in the early days of hang gliding most of the sport's development occurred through the trial and error of the participants. However, the equipment now-a-days is much more advanced and includes quick deploy parachutes. The greatest improvement in safety, though, has come from proper training from qualified instructors.