Pilot’s emergency device (7,4)
I believe the answer is:
ejector seat
'pilot's emergency device' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for ejector seat that I've seen before include "form of escape" , "It throws pilot to safety" , "Pilot's emergency device" , "Warplane escape mechanism" , "Device for a pilot who wants to depart quickly!" .)