Airman crashing in harbour (6)
I believe the answer is:
marina
'harbour' is the definition.
(marina is a type of harbour)
'airman crashing' is the wordplay.
'crashing' indicates an anagram.
'airman' anagrammed gives 'MARINA'.
'in' acts as a link.
(Other definitions for marina that I've seen before include "where yachts moor" , "Airman (anag)" , "Docking place for pleasure craft" , "Base for pleasure boats" , "seaside area" .)