British fliers going back a long way (3)
I believe the answer is:
far
'a long way' is the definition.
(I've seen this before)
'british fliers going back' is the wordplay.
'british fliers' becomes 'RAF' (Royal Air Force).
'going back' is a reversal indicator.
'raf' written backwards gives 'FAR'.
(Other definitions for far that I've seen before include "Remote" , "Very much" , "At a great distance way" , "Distant" , "A long, long way to go" .)