Test bomb underneath rising chopper (7)
I believe the answer is:
examine
'test' is the definition.
(I know that test is a more specific form of check)
'bomb underneath rising chopper' is the wordplay.
'bomb' becomes 'mine' (I've seen this before).
'underneath' is a charade indicator (letters next to each other) (in a down clue, some letters go under others).
'rising' says the letters should be written backwards (in a down clue, letters go up).
'chopper' becomes 'axe' (something which chops).
'axe' backwards is 'exa'.
'mine' after 'exa' is 'EXAMINE'.
(Other definitions for examine that I've seen before include "Test or study carefully" , "research" , "Investigate" , "Inspect, peruse closely" , "Inspect , test" .)