Areas for parked aircraft (6)
I believe the answer is:
aprons
'areas for parked aircraft' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for aprons that I've seen before include "Garments worn in kitchens" , "Kithchen garments or airfield areas" , "Paved areas for out-of-use aircraft" , "Protective garments for aircraft" , "Protective garment" .)