Digital Glider Airman [PSOne Books] Japan

Glider aircraft are heavier-than-air craft that are supported in flight by the dynamic reaction of the air against their lifting surfaces, and whose free flight does not depend on an engine.[1] Mostly these types of aircraft are intended for routine operation without engines, though engine failure can force other types of aircraft to glide. Some gliders have engines for extending their flights and some have engines powerful enough to launch.