volplane
Concise Oxford English Dictionary © 2008 Oxford University Press:
volplane /ˈvɒlpleɪn/ Aeronautics
▶noun a controlled dive at a steep angle, especially by an aircraft with the engine shut off. ▶verb (of an aircraft) make such a dive.
– origin early 20th cent.: from Fr. vol plané, lit. ‘glided flight’.
'volplane' also found in these Oxford entries:

