to reduce the manufacturing effort and {HEAD ~ expense} of {TAIL ~ such large surface area structural aircraft components} 
of
to reduce the manufacturing effort and { HEAD ~ expense } of { TAIL ~ such large surface area structural aircraft components }
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL