The error signal from summer 82 affects {TAIL ~ the constant speed drive} 66 of each channel in {HEAD ~ an identical manner} 
The error signal from summer 82 affects { TAIL ~ the constant speed drive } 66 of each channel in { HEAD ~ an identical manner }
OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD