How are blade angle changes made in constant-speed counterweight propellers and two-position counterweight propellers?

How are blade angle changes made in constant-speed counterweight propellers and two-position counterweight propellers?

• A. by hydraulic and centrifugal forces
• B. by electric motors
• C. by manual twist control
• D. by pneumatic pressure

Answer: (A)

Blade angle changes in these propellers are driven by hydraulic pressure acting in the propeller hub, with centrifugal forces from the internal counterweights shaping how that pitch is set at a given speed. The governor monitors engine RPM and modulates oil pressure to move the blade-pitch actuating mechanism. As oil pressure changes, a piston or vane inside the hub shifts the blade angle. Meanwhile, the counterweights respond to rpm: higher rpm increases centrifugal force, which tends to push the mechanism toward higher pitch and helps set or lock the pitch to the desired position. This combination keeps constant-speed propellers at the chosen RPM and allows two-position counterweight designs to switch between two fixed pitch settings.

Blade angle changes in these propellers are driven by hydraulic pressure acting in the propeller hub, with centrifugal forces from the internal counterweights shaping how that pitch is set at a given speed. The governor monitors engine RPM and modulates oil pressure to move the blade-pitch actuating mechanism. As oil pressure changes, a piston or vane inside the hub shifts the blade angle. Meanwhile, the counterweights respond to rpm: higher rpm increases centrifugal force, which tends to push the mechanism toward higher pitch and helps set or lock the pitch to the desired position. This combination keeps constant-speed propellers at the chosen RPM and allows two-position counterweight designs to switch between two fixed pitch settings.