One whose promotion is up in the air (9)
I believe the answer is:
skywriter
'one whose promotion' is the definition.
I know that 'promotion' relates to this answer.
'up in the air' is the wordplay.
I cannot quite see how this works, but
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is found within the answer.
'air' could be 'sky' and 'sky' is found in the answer.
The remaining letters 'wrier' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
'is' acts as a link.
(Other definitions for skywriter that I've seen before include "Aerial advertiser using smoke" , "Pilot creating a message with smoke trails" , "author of heavenly words" .)