Crank heading for Western Isle (5)
I believe the answer is:
winch
'crank' is the definition.
(I've seen this before)
'heading for western isle' is the wordplay.
'heading for' suggests taking the first letters.
'isle' becomes 'inch' (inch can mean a small island).
The initial letter of 'western' is 'w'.
'w'+'inch'='WINCH'
(Other definitions for winch that I've seen before include "Pull up" , "Hauling/lifting device" , "Hoist" , "Crank" , "Hoisting machine" .)