A beener or D ring was attached to each trainee via a rappel seat that went around his waist and upper thighs.
He paraglided, scuba dived, and even tried to rappel down Mt. Rushmore before he was rebuffed by park officials.
In time the X Troop was trained to rappel and parachute; to use guns, bayonets and knives; and even to kill with bare hands.
1931, "mountaineering technique for descending steep faces," from French rappel, literally "recall" (Old French rapel), from rapeler "to recall, summon" (see repeal (v.)). The same word had been borrowed earlier (1848) to mean "a drum roll to summon soldiers."
1957 in the mountaineering sense; see rappel (n.). Related: Rappeled; rappelling.