a cold air take off 17 downstream of {HEAD ~ the fan} 6 of {TAIL ~ the engine}, 
a cold air take off 17 downstream of { HEAD ~ the fan } 6 of { TAIL ~ the engine } ,
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH