Get into trouble about check on outside compartment (7)
I believe the answer is:
cockpit
'compartment' is the definition.
(cockpit is a kind of compartment)
'get into trouble about check on outside' is the wordplay.
'get into trouble' becomes 'copit' (to cop it is to receive punishment).
'about' means one lot of letters goes inside another.
'on outside' says to hollow out the word (remove centre letters) (letters on the outside of the word used).
'check' with its centre taken out is 'ck'.
'copit' placed around 'ck' is 'COCKPIT'.
(Other definitions for cockpit that I've seen before include "Place where there was fighting" , "Main venue" , "Front section of a plane" , "Site of numerous battles or campaigns" , "Place for aircraft's pilot and crew" .)