A glider is a fixed-wing aircraft that is supported in flight by the dynamic reaction of the air against its lifting surfaces, and whose free flight does not depend on an engine.[1] Most gliders do not have an engine, although motor-gliders have small engines for extending their flight when necessary by sustaining the altitude (normally a sailplane is on a continuously descending slope) with some being powerful enough to take off self-launch .

There is a wide variety of types differing in the construction of their wings, aerodynamic efficiency, location of the pilot, controls and intended purpose. Most exploit meteorological phenomena to maintain or gain height. Gliders are principally used for the air sports of gliding, hang gliding and paragliding. However some spacecraft have been designed to descend as gliders and in the past military gliders have been used in warfare. Some simple and familiar types of glider are toys such as the paper plane and balsa wood glider.

DevelopmentMain article: Glider (sailplane)In the inter-war years, recreational gliding flourished in Germany under the auspices of Rhön-Rossitten. In the United States, the Schweizer brothers of Elmira, New York, manufactured sport sailplanes to meet the new demand. Sailplanes continued to evolve in the 1930s, and sport gliding has become the main application of gliders. As their performance improved, gliders began to be used to fly cross-country and now regularly fly hundreds or even over a thousand of kilometers in a day,[10] if the weather is suitable.

Military gliders were developed during World War II by a number of countries for landing troops. A glider – the Colditz Cock – was even built secretly by POWs as a potential escape method at Oflag IV-C near the end of the war in 1944.

Source: Wikipedia