Turn part of organ air-passage (8)
I believe the answer is:
windpipe
'passage' is the definition.
(I know that windpipe is a type of cartilaginous tube)
'turn part of organ' is the wordplay.
'turn' becomes 'wind' (I've seen this before).
'part of organ' becomes 'pipe' ('pipe' is part of 'organ').
'wind'+'pipe'='WINDPIPE'
'air' acts as a link.
This may not be right. It may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for windpipe that I've seen before include "It conveys air from the larynx to the lungs" , "airline" , "breathing space" , "The trachea, less formally" , "Common name for the trachea" .)