FAA Powerplant Written Practice Test

The centrifugal twisting force of a propeller has what effect on the pitch angle?

1. Increases the pitch angle

2. Reduces the pitch angle

3. Has no effect on pitch angle

4. Fluctuates the pitch angle

The correct answer is: Reduces the pitch angle

The centrifugal twisting force of a propeller tends to reduce the pitch angle. This is due to the nature of the forces acting on the propeller blades as they rotate. As the blades spin, the centrifugal force exerted on the blades creates a tendency for them to twist outward, which results in a decrease in the angle of attack relative to the airflow. This reduction in pitch angle can enhance the performance at certain operating conditions, particularly at higher speeds or when the propeller is subjected to varying loads. Understanding this principle is crucial for comprehending how propeller dynamics influence thrust generation and overall engine efficiency. It highlights the importance of balancing these forces when designing propellers and optimizing their performance for specific flight conditions.