The object of the present invention is to provide {HEAD ~ a helicopter rotor} of {TAIL ~ the above described type} which will be substantially free from such disadvantage 
of
The object of the present invention is to provide { HEAD ~ a helicopter rotor } of { TAIL ~ the above described type } which will be substantially free from such disadvantage
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH