The circuit requires {HEAD ~ reduction} of {TAIL ~ the engine speed} to a speed below the lower response speed in order to restore the response speed of the speed responsive control to the predetermined speed 
of
The circuit requires { HEAD ~ reduction } of { TAIL ~ the engine speed } to a speed below the lower response speed in order to restore the response speed of the speed responsive control to the predetermined speed
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH