Propeller Control:
There is no separate propeller control selector for this engine / propeller combination. Instead of a separate propeller control lever, the governor is designed to operate from engine control inter-connections (Fig 81 & Fig 82). At the top of the governor is a lever and mechanism for selecting either constant speed operation or feather, whilst below this there is a normal rack and pinion rev / min selector which varies the value of the governor spring. The levers at these control points are linked into the engine control system as follows:
• Constant Speed or Feather - The lever at the top of the governor unit is called the manual feathering lever (Fig 81& Fig 82). It is inter-connected with the high pressure shut-off cock (HP cock) control so that when the HP cock is at the run or 'shut-off' position, the governor is set for constant speeding. When the high pressure fuel cock control lever is moved beyond fuel shut-off to the feather position the manual feathering lever pawl mechanically lifts the governor piston valve to direct pressure oil to the coarse pitch side on the pitch change piston.
Rev / min Selector - The engine throttle control is linked to a normal rack and pinion control in the governor unit (Fig. 81 & Fig. 82) so that movement of the throttle control acts through inter-connecting linkage to vary the load imposed upon the governor spring to act as a rev / min selector.