Some aircraft go up a long way! (3)
I believe the answer is:
far
'a long way' is the definition.
(I've seen this in another clue)
'some aircraft go up' is the wordplay.
'some' says the answer is hidden in the clue (some parts of the word are used).
'go up' is a reversal indicator (I've seen 'going up' mean this).
'raf' can be found hidden inside 'aircraft'.
'raf' backwards is 'FAR'.
(Other definitions for far that I've seen before include "At a great distance way" , "Remote" , "Very much" , "A long, long way to go" , "Distant" .)