What is the function of the centrifugal stop pin?

The function of the centrifugal stop pin is critical in preventing the propeller from feathering below a specific RPM threshold, which in this case is 800 RPM. Feathering is a process where the blades of the propeller are rotated to a position that minimizes drag, typically used during engine failure or shutdown to reduce aerodynamic drag on the aircraft.

By stopping the propeller from feathering at RPMs below 800, the centrifugal stop pin ensures that there is still sufficient thrust produced by the propeller to maintain controllability and assist in managing the flight dynamics of the aircraft. When the engine is running normally, the propeller needs to maintain a certain pitch angle to provide enough lift and control. If feathering were allowed too early (below 800 RPM), it could lead to a loss of power and make handling the aircraft more difficult, especially during critical phases of flight such as takeoff and approach.

This function of the centrifugal stop pin is essential for safety and performance, as it directly influences the aircraft's ability to respond to pilot inputs and maintain flight stability.