Normandy area is trashed in rating (8,6)
I believe the answer is:
ordinary seaman
'rating' is the definition.
('rating' can mean a non-commissioned navy sailor)
'normandy area is trashed' is the wordplay.
'trashed' is an anagram indicator.
'normandy'+'area'+'is'='normandyareais'
'normandyareais' anagrammed gives 'ORDINARY SEAMAN'.
'in' is the link.
(Other definitions for ordinary seaman that I've seen before include "OS in full" , "Crew member" , "Lowest rank of Royal Navy sailor" .)