The rotor spindle and {TAIL ~ controls} pass through {HEAD ~ a central hole} between the spar caps 
The rotor spindle and { TAIL ~ controls } pass through { HEAD ~ a central hole } between the spar caps
OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH