A rotor for rotary wing aircraft has a tip to tip flex beam spar and {HEAD ~ torsionally stiff hollow blades} bonded to the spar throughout the tip most portion of {TAIL ~ the blades} 
A rotor for rotary wing aircraft has a tip to tip flex beam spar and { HEAD ~ torsionally stiff hollow blades } bonded to the spar throughout the tip most portion of { TAIL ~ the blades }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL