RAF tutors bombing surface (9)
I believe the answer is:
astroturf
'surface' is the definition.
(artificial grass surface)
'raf tutors bombing' is the wordplay.
'bombing' is an anagram indicator.
'raf'+'tutors'='raftutors'
'raftutors' anagrammed gives 'ASTROTURF'.
(Other definitions for astroturf that I've seen before include "Artificial grass" , "play area possibly" , "substitute on pitch?" .)