FAA Ground School Practice Test

What is one significant advantage of using a constant-speed propeller?

1. It reduces fuel consumption automatically

2. It offers less vibration for smoother flights

3. It permits the pilot to select the blade angle for efficient performance

4. It increases the propeller's diameter for better lift

The correct answer is: It permits the pilot to select the blade angle for efficient performance

The significant advantage of using a constant-speed propeller is that it permits the pilot to select the blade angle for efficient performance. This capability allows the pilot to adjust the propeller's pitch to optimize performance for various phases of flight, such as takeoff, climb, cruise, and descent. By changing the blade angle, the pilot can enhance efficiency in different flight conditions, leading to improved fuel consumption and overall aircraft performance. In contrast, other choices do not accurately represent the primary function of a constant-speed propeller. Fuel consumption can be influenced by various factors, but the propeller itself does not automatically reduce consumption; it is the pilot's manipulation of the pitch that can affect efficiency. Similarly, while a constant-speed propeller may result in smoother operation due to optimized blade angles, the reduction of vibration is not the principal advantage of this type of propeller. Lastly, increasing the diameter of a propeller does not relate to the function of a constant-speed mechanism; instead, it involves different aerodynamic considerations that are not inherent to the adjustable blade angle functionality.