Protective clothing in airport area (5)
I believe the answer is:
apron
This clue is a double definition.
'protective clothing' is the first definition.
(I've seen this in another clue)
'airport area' is the second definition.
(I've seen this in another clue)
'in' is the link.
(Other definitions for apron that I've seen before include "Pinafore" , "item of protective clothing" , "Airport area for manoeuvring and loading planes" , "Aircraft parking area" , "stage perhaps" .)