The swirling stream of air circulates about {HEAD ~ the common axis} of the nozzles 20, 30 and {TAIL ~ centering surfaces} 25, 34 
of
The swirling stream of air circulates about { HEAD ~ the common axis } of the nozzles 20 , 30 and { TAIL ~ centering surfaces } 25 , 34
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH