Craft is likely to run on air (8)
I believe the answer is:
woodwork
'craft' is the definition.
(woodwork is a kind of craft)
'likely to run on air' is the wordplay.
I cannot really understand how this works, but
'run' could be 'work' (synonyms) and 'work' is located in the answer.
'on' could be 'o' (I've seen this in other clues) and 'o' is located in the answer.
This explanation may well be incorrect...
'is' acts as a link.
(Other definitions for woodwork that I've seen before include "pine for this pursuit?" , "Carpentry" , "Things come crawling out of it" .)