What is the primary function of the Prop Governor?

The primary function of the prop governor is to maintain a constant RPM by varying propeller pitch. The prop governor works through a mechanism that adjusts the angle of the propeller blades in response to changes in engine RPM. When the RPM drops below a set point, the governor will increase the blade angle (pitch), which reduces the propeller's thrust and allows the engine to catch up. Conversely, if the RPM exceeds the set point, the governor will decrease the pitch, increasing thrust and helping to bring the RPM back down to the desired level. This continuous adjustment helps ensure optimal engine performance, efficiency, and power management, particularly during changes in power settings or flight maneuvers.

In contrast, increasing engine power would not be the function of the prop governor, as its role is centered on managing RPM rather than boosting thrust. Cooling the engine is typically managed through a separate system involving airflow and cooling fluids, not the prop governor. Auxiliary engine power also refers to additional power sources, not the operation of the propeller pitch or RPM control. Thus, the function of the prop governor is specifically to maintain constant RPM by varying the pitch of the propeller blades.