Cut in personnel (4)
I believe the answer is:
This clue is a double definition.
'cut' is the first definition.
(crew cut is a type of haircut)
'personnel' is the second definition.
'in' acts as a link.
(Other definitions for crew that I've seen before include "Ship's sailors" , "Sailors -- boasted" , "made triumphalist noises" , "A kind of short cut" , "Staff of boat" .)