1) A very light aircraft, also called
sailplane without
engine thrust. It needs to be lifted up by a small
prop aircraft. Once it is at a sufficent altitude, the cable used for lifting up is detached from its nose and the glider flies freely. In order to maintain its altitude, glider
pilots use to catch the so called lifting or ascending windstreams, usually generated by hot air moving up to clouds, and mountainous landscapes.
2)Usually told about an aircraft who has lost any thrust because of engine failure or running out of
fuel.
1) "A good pilot should be able to fly gliders (sailplanes) before he flies an engine airplane."
2) "DELTA 2,
Bingo fuel!
RTB"
...after a while...
"DELTA 2, we're gliders!"
"BASE to DELTA 2, uncorrect, you're
fucked up!"