Grounds to have ground to air lane (9)
I believe the answer is:
rationale
'grounds' is the definition.
(I've seen this in another clue)
'ground to air lane' is the wordplay.
'ground' indicates anagramming the letters ('grind' the letters into a new form).
'to'+'air'+'lane'='toairlane'
'toairlane' with letters rearranged gives 'RATIONALE'.
'to have' acts as a link.
(Other definitions for rationale that I've seen before include "Underlying principle" , "Logical reasons (for action)" , "Philosophy" , "Good reason" , "Logical reason for action" .)