Definition 1 of 2
Definition
A heavier-than-air 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. Gliders are typically launched by aerotow, ground winch, or auto tow, and sustain or extend flight by using rising air such as thermals, ridge lift, or wave lift.
Plain English
An aircraft with wings but no engine that is towed or launched into the air and then flies by riding rising air currents and gradually descending.
Context Anchor
Seen in aircraft category discussions, pilot certificate ratings, right-of-way rules, launch procedures, and soaring operations.
Derivation
From the Old English 'glidan,' meaning to move smoothly and quietly. The name reflects the aircraft's defining characteristic: powered flight is replaced by a smooth, gradual descent through the air.
Why Pilots Care
Provides training in energy management and serves as a realistic platform for practicing engine-out emergencies.
Intuition Check
Do not assume a glider is only a toy or that every glider has no engine at all. In aviation, the key point is that its flight does not depend mainly on engine power.
Example Sentence 1
The glider released from the tow plane at 3,000 feet and circled in a thermal to gain altitude.
Example Sentence 2
During the checkride the applicant demonstrated a precision approach and landing in the glider.