FREE AMT Hydraulic and Pneumatic Systems Questions and Answers

Question 1

An aircraft's hydraulic system reservoir is found to be pressurized with bleed air from the engine's compressor section. What is the primary reason for pressurizing the reservoir?

Accepted Answer

To prevent hydraulic fluid from foaming at high altitudes.

Answer

To increase the system's overall operating pressure.

Answer

To provide a backup source of pneumatic pressure for emergency systems.

Answer

To cool the hydraulic fluid before it enters the pump.

Question 2

A technician is servicing a large transport category aircraft and needs to identify the type of hydraulic fluid used in the main system. Which of the following is the most reliable method to determine the correct fluid type?

Accepted Answer

Consulting the aircraft manufacturer's maintenance manual or the placard on the reservoir.

Answer

Checking the color of the fluid in the reservoir sight glass.

Answer

Assuming it uses the most common type, Skydrol, because it is a large aircraft.

Answer

Sending a sample of the fluid to a laboratory for analysis.

Question 3

What is the fundamental operating principle that allows a hydraulic system to transmit a small input force into a large output force?

Accepted Answer

Pascal's Law

Answer

Bernoulli's Principle

Answer

Charles's Law

Answer

The Venturi Effect

Question 4

During a pre-flight inspection, a technician notices that the brake system pressure is holding steady even though the main hydraulic pumps are offline. Which component is responsible for maintaining this pressure for a short duration?

Accepted Answer

An accumulator

Answer

A pressure relief valve

Answer

A check valve

Answer

A shuttle valve

Question 5

A technician is troubleshooting a hydraulic system that is operating sluggishly. The fluid in the reservoir appears milky or foamy. Which of the following is the most likely cause?

Accepted Answer

Air is entering the system, likely through a leak in a suction line.

Answer

The system's check valve has failed in the open position.

Answer

The hydraulic pump's shear shaft has failed.

Answer

The system is filled with a hydraulic fluid of the wrong viscosity.

Question 6

Which of the following is a primary advantage of a pneumatic power system compared to a hydraulic system on an aircraft?

Accepted Answer

Air is universally available and there is no need for a return line, saving weight.

Answer

Pneumatic systems can generate higher operating pressures.

Answer

Pneumatic components are less susceptible to contamination.

Answer

Pneumatic systems provide smoother and more precise control over actuators.