A new RAF is a long way off (4)
I believe the answer is:
afar
'long way off' is the definition.
(I've seen this in another clue)
'a new raf' is the wordplay.
'new' is an anagram indicator.
'raf' is an anagram of 'far'.
'a'+'far'='AFAR'
'is a' acts as a link.
(Other definitions for afar that I've seen before include "(From/at) a great distance" , "Inhabitant of Ethiopia" , "Unusually distant" , "Many miles away" , "Not in this neighbourhood" .)