FAA Powerplant Written Practice Test

Counterweights on constant-speed propellers are generally used to aid in what process?

1. Decreasing blade angle

2. Increasing blade angle

3. Stabilizing the propeller during flight

4. Decreasing rotational speed

The correct answer is: Increasing blade angle

Counterweights on constant-speed propellers play a crucial role in adjusting the blade angle during flight. Specifically, they are primarily used to aid in increasing the blade angle. The counterweights work against the centrifugal force generated by the propeller's rotation, facilitating the movement of the blades to a higher angle of attack. This is essential for maintaining optimal performance and efficiency during various phases of flight, particularly during climb or when increased thrust is required. The mechanism involves the use of oil pressure to move the blades, and the counterweights help ensure that, as the blades attempt to move toward a lower pitch (decreasing blade angle), they can be efficiently positioned to a higher pitch (increasing blade angle) when needed. This allows the pilot to achieve better control over engine power and thrust, especially when adjustments are necessary for changing flight conditions.