Glider is described as an unpowered aircraft capable of maintaining altitude only briefly after release from tow, then gliding to earth.
See also:
"Glider" is in the NAICS Code "487990"
Scenic and Sightseeing Transportation, Other
Glider excursions
Ref: 124416/2006-10-28
Glide is described as an aircraft without an engine. Gliders are towed into the air by a powered aircraft or by a towline attached to a winch on the ground, and soar higher on rising currents of air