Supply of gas for a plane? (3)
I believe the answer is:
jet
'for a plane?' is the definition.
(jet plane)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for jet that I've seen before include "Rush" , "Deep black" , "Rapid stream of liquid or gas" , "flies fast" , "Kind of plane, or a glossy black" .)