FAA Powerplant Written Practice Test

In a large aircraft with a turboprop installation, how is the propeller controlled?

1. By a mechanical lever

2. By the engine power lever

3. Through electronic control systems

4. Using hydraulic controls

The correct answer is: By the engine power lever

The propeller control in a large aircraft with a turboprop installation is primarily managed through the engine power lever. This system allows the pilot to adjust the engine's thrust by controlling the fuel flow to the engine, which indirectly influences the propeller's blade angle and speed. When the power lever is manipulated, it sends signals to the propeller control unit, which in turn makes the necessary adjustments to maintain the desired thrust for various phases of flight, such as takeoff, cruising, or landing. While other methods, such as mechanical levers, electronic control systems, and hydraulic controls, are used in certain aircraft systems, the power lever remains central to the operation of turboprop propellers because it gives the pilot a direct means to manage engine power and propeller performance dynamically. This integration helps optimize engine efficiency and performance across a range of operating conditions.