Aviation complex (7)
I believe the answer is:
airport
'aviation complex' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for airport that I've seen before include "Strange pit roar in the travel terminal" , "Aviation centre" , "Heathrow, for example" , "Charles de Gaulle, for instance" , "E.g. Prestwick, Gatwick" .)