For governor operation instruction please refer “Installation and Operation Manual”.
The following text describes the general principles of propeller control.


The governor quadrant and push-pull type controls are arranged to provide high rpm when full forward and low rpm when pulled back. The governor will control over a certain rpm band which can be covered by moving the control through a portion of its travel at the forward end of its range when the throttle is well forward.
Most ground operation of the aircraft is done with full forward position of the governor control lever, so starting and stopping should likewise be done in low pitch, high rpm position.
An operational check of the governor and propeller should be made during run-up.
Takeoff should be made with governor setting FULL FORWARD to obtain take-off rpm.
During landing, the governor control should be FULL FORWARD so that the propeller will be in a position for immediate take-off or go-around, if necessary.


  1. Feather the governor several times after installation is made in order to purge air from system, and at least once during each run up.
  2. Feathering on the ground is accomplished by reducing propeller speed to 1000 – 1500 rpm and pulling governor control FULL BACK against the stop. Do not feather when operating at high manifold pressure. Unfeathering is accomplished by returning governor control to normal range with engine running.
  3. Emergency or practice feathering in flight is accomplished by pulling back on governor control to limit of travel.
  4. Unfeathering in flight is accomplished by:
    • restarting engine with the governor control in low rpm range. This will impose heavy loads on the engine and mount unless care is exercised to keep manifold pressure low until the propeller blades move enough to aid rotation.
    • Cranking the engine fuel off) with the starter until the propeller blade angle is reduced and windmilling begins.

      Restart or cranking imposes the danger of fire and always requires a good starter and battery. The time required to unfeather may be appreciable.
    • Using an electric unfeathering pump or an unfeathering accumulator which discharges oil through the governor to the propeller to rotate the propeller blades to near windmilling. The engine may then be started without imposing any heavy load on the engine or mounts and without a heavy drain on the battery. Fire hazard is greatly reduced.


During unfeathering, the engine rpm is always limited by the governor speed setting regardless of how the unfeathering is accomplished. To avoid a transient Overspeed, keep the governor speed setting below maximum until rpm has stabilized.