FAA Ground School Practice Test

In an aircraft with a constant-speed propeller, how is engine operation controlled?

1. The throttle controls power and the propeller control regulates the fuel flow

2. The manifold pressure gauge displays RPM and the throttle controls flight speed

3. The throttle controls power outlet and the propeller control regulates engine RPM

4. The propeller control adjusts blade angle only during takeoff

The correct answer is: The throttle controls power outlet and the propeller control regulates engine RPM

In an aircraft equipped with a constant-speed propeller, engine operation is regulated through a combination of throttle settings and propeller control. The throttle is responsible for controlling the power output of the engine, which affects how much fuel and air mixture is supplied to the engine. This directly influences the overall power produced by the engine. Simultaneously, the propeller control manages the blade pitch angle of the propeller. With a constant-speed propeller system, the goal is to maintain a specific engine RPM regardless of the power setting. The propeller control adjusts the blade angle to optimize performance based on varying flight conditions or power settings, ensuring efficient operation and maintaining the desired RPM. In this context, the chosen answer accurately reflects how the throttle manages engine power while the propeller control specifically governs the RPM by adjusting the pitch of the propeller blades. This dual control system allows for better performance and efficiency in various phases of flight.