The spar spaced apart spar caps which have {HEAD ~ a dual beam cross section} in the region not bonded to the blades so that {TAIL ~ the spar} is twistable for pitch control 
The spar spaced apart spar caps which have { HEAD ~ a dual beam cross section } in the region not bonded to the blades so that { TAIL ~ the spar } is twistable for pitch control
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH