Political exile maybe once before commandeering fighter plane (6)
I believe the answer is:
emigre
'political exile' is the definition.
(I've seen this in another clue)
'once before commandeering fighter plane' is the wordplay.
'once before' becomes 'ere' (archaic term for 'before').
'commandeering' is an insertion indicator.
'fighter plane' becomes 'mig' (I've seen this in another clue).
'ere' going around 'mig' is 'EMIGRE'.
'maybe' is the link.
(Other definitions for emigre that I've seen before include "Person forced to flee his country for political reasons" , "Someone leaving the country for good" , "One who has left his country for political reasons" , "Person settling in another country" , "he was driven out of the country" .)