Airframe Mechanic Aircraft Landing Gear Systems Questions and Answers

Question 1

An aircraft's retractable landing gear system is equipped with a squat switch, also known as a weight-on-wheels switch. What is the primary function of this switch?

Accepted Answer

To prevent inadvertent retraction of the landing gear while the aircraft is on the ground.

Answer

The squat switch is a safety device that opens an electrical circuit when the weight of the aircraft is on the landing gear, preventing power from reaching the gear retraction motor. This ensures the gear cannot be raised while the aircraft is on the ground.

Question 2

When servicing an air/oil oleo shock strut, a mechanic notices that the strut bottoms out on landing but functions normally during taxi. What is the most likely cause of this issue?

Accepted Answer

Low hydraulic fluid level.

Answer

If an oleo strut bottoms on landing, it indicates a lack of hydraulic fluid to cushion the initial impact. During taxi, the loads are less severe, so the remaining fluid and air pressure may appear to function correctly. Excessive air pressure would make the strut too stiff, and worn seals would likely cause fluid leaks.

Question 3

What is the primary purpose of the torque links (also known as scissors) on a landing gear strut?

Accepted Answer

To prevent the piston from rotating within the cylinder and maintain wheel alignment.

Answer

Torque links connect the upper, fixed part of the strut to the lower, sliding piston, preventing relative rotation between them. This keeps the wheel aligned with the aircraft's direction of travel and prevents shimmy.

Question 4

A mechanic is performing a landing gear retraction test on a large aircraft. Which of the following is an essential safety precaution that must be taken before beginning the test?

Accepted Answer

Ensure the aircraft is properly supported on jacks and all personnel and equipment are clear of the gear.

Answer

A landing gear retraction test involves the full movement of the gear. It is critical to have the aircraft securely on jacks to simulate an in-flight condition and to ensure the area is completely clear to prevent injury or damage. Ground locks must be removed to allow the gear to retract.

Question 5

Which of the following is the correct fluid and gas combination for servicing a standard oleo-pneumatic shock strut?

Accepted Answer

Mineral-based hydraulic fluid and nitrogen.

Answer

Standard oleo struts are serviced with mineral-based hydraulic fluid (like MIL-H-5606) and an inert gas, typically nitrogen. Nitrogen is used because it is dry and less susceptible to pressure changes with temperature compared to compressed air, and it does not support combustion.

Airframe Mechanic Certification Practice Test

Airframe Mechanic Certification Practice Test

Airframe Mechanic Aircraft Landing Gear Systems Questions and Answers