An air vehicle propulsion system incorporates an engine core with {HEAD ~ a power shaft} to drive {TAIL ~ an outer blade row} 
to drive
An air vehicle propulsion system incorporates an engine core with { HEAD ~ a power shaft } to drive { TAIL ~ an outer blade row }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL