Wing part (7)
I believe the answer is:
aileron
'wing part' is the definition.
('aileron' is part of 'wing')
This is all the clue.
(Other definitions for aileron that I've seen before include "An oriel (anag.); plane part" , "Aircraft control surface" , "Near oil (anag)" , "Lateral control in aircraft" , "Movable wing surface" .)