A difficulty to confront at the air terminal (5)
I believe the answer is:
facer
'a difficulty' is the definition.
(facer is a kind of difficulty)
'confront at the air terminal' is the wordplay.
'confront' becomes 'face' (synonyms).
'at' says to put letters next to each other.
'terminal' says to take the final letters (terminal refers to the end).
The final letter of 'air' is 'r'.
'face'+'r'='FACER'
'to' is the link.
(Other definitions for facer that I've seen before include "A sudden serious difficulty" , "Informally, a sudden great difficulty" , "challenge" , "One who confronts" , "sudden problem" .)