Each of the cooling shoes includes an air expansion chamber communicating through a shoe inlet when in {TAIL ~ use} with a supply of {HEAD ~ air} under pressure 
Each of the cooling shoes includes an air expansion chamber communicating through a shoe inlet when in { TAIL ~ use } with a supply of { HEAD ~ air } under pressure
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH