FAA Powerplant Written Practice Test

During the on-speed condition of the propeller, what balance occurs?

1. The engine power exceeds the propeller drag.

2. The centrifugal force of the governor flyweights equals the speeder spring tension.

3. The propeller pitch stabilizes at high angle.

4. The propeller experiences maximum drag.

The correct answer is: The centrifugal force of the governor flyweights equals the speeder spring tension.

The correct answer highlights a critical aspect of propeller operation under the on-speed condition, which refers to the scenario where the propeller governor adjusts to maintain optimal engine speed. In this state, an equilibrium is reached where the centrifugal force produced by the governor flyweights exactly balances the tension of the speeder spring. This balance is crucial because it allows the governor to regulate the pitch of the propeller blades adequately, ensuring that they maintain the desired rotational speed during flight or operation. If the centrifugal force exceeds the speeder spring tension, the governor would adjust the propeller pitch to decrease drag and increase speed, while the opposite would occur if the spring tension were to exceed the centrifugal force. Understanding this balance is vital in ensuring efficient engine performance and preventing overspeed or underspeed conditions, which could lead to engine or propeller damage. This knowledge is foundational for anyone involved in powerplant operations and maintenance, as it underscores the function of the governor system in propeller control.