Plane- wing part (7)
I believe the answer is:
aileron
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">plane-wing part</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for aileron that I've seen before include "Movable part of an aircraft's wing" , "Aeroplane's wing flap" , "seen on the wing" , "Hinged flap an an aeroplane wing" , "Trailing-edge flap" .)