FREE AMT Aircraft Propeller Systems Questions and Answers

Question 1

In a constant-speed propeller governor, what is the primary function of the flyweights?

Accepted Answer

To sense engine RPM and control the position of the pilot valve.

Answer

The flyweights spin at a speed proportional to the engine RPM. Through centrifugal force, they move inward or outward depending on speed. This movement directly controls the pilot valve, which then ports oil to or from the propeller hub to change the blade pitch and maintain the selected RPM.

Question 2

What is the primary reason for feathering the propeller of a failed engine on a multi-engine aircraft?

Accepted Answer

To align the blades with the relative wind to minimize aerodynamic drag.

Answer

Feathering involves turning the propeller blades to be nearly parallel with the direction of flight. This presents the smallest profile to the oncoming air, which significantly reduces the drag produced by the windmilling propeller of a failed engine, improving the aircraft's single-engine performance.

Question 3

During takeoff in an aircraft with a constant-speed propeller, the propeller blade pitch is set to:

Accepted Answer

A low pitch, high RPM position to allow the engine to develop maximum power.

Answer

For takeoff, the propeller is set to a low pitch (high RPM) position. This light load allows the engine to accelerate to its maximum rated RPM and produce maximum power for takeoff and initial climb.

Question 4

A pilot reports that after an in-flight engine shutdown on a multi-engine aircraft, the propeller failed to feather and continued to windmill. Which of the following is a plausible mechanical reason for this failure?

Accepted Answer

The centrifugal 'stop pins' engaged because the engine RPM dropped too low before feathering was initiated.

Answer

Many propeller systems have centrifugal stop pins (or latches) that prevent the propeller from feathering during normal engine shutdown on the ground. These pins are held in place by springs and are only retracted by centrifugal force above a certain low RPM (e.g., 500-800 RPM). If the pilot waits too long to feather a failed engine and the RPM drops below this threshold, the pins will engage and prevent the blades from moving to the feather position.

Question 5

Which of the following describes the function of a propeller synchronization system on a multi-engine aircraft?

Accepted Answer

It adjusts the RPM of the 'slave' engine(s) to exactly match the RPM of the 'master' engine.

Answer

A propeller synchronization system is used to eliminate the unpleasant 'beat' or 'drone' caused by propellers turning at slightly different speeds. It designates one engine as the 'master' and automatically adjusts the propeller governor of the 'slave' engine(s) to maintain exactly the same RPM.

(AMT) Aviation Maintenance Technician Practice Test

(AMT) Aviation Maintenance Technician Practice Test

FREE AMT Aircraft Propeller Systems Questions and Answers