ACS Landing Gear & Brake Systems 1 — Questions and Answers
Question 1: What is the primary purpose of an oleo strut in aircraft landing gear?
- To steer the nose wheel
- To absorb landing shock through hydraulic fluid and compressed nitrogen (Correct answer)
- To lock the gear in the retracted position
- To provide electrical bonding between the gear and airframe
Correct answer: To absorb landing shock through hydraulic fluid and compressed nitrogen
An oleo strut uses hydraulic fluid and compressed nitrogen to absorb and dissipate the energy of landing impact.
Question 2: When servicing an oleo strut, the correct fluid level is verified by:
- Checking the fluid reservoir sight glass
- Deflating the strut fully, adding fluid to the specified level, then re-inflating with nitrogen (Correct answer)
- Using a pressure gauge on the Schrader valve
- Measuring strut extension with a ruler only
Correct answer: Deflating the strut fully, adding fluid to the specified level, then re-inflating with nitrogen
The correct procedure is to fully deflate the strut, fill it with the specified hydraulic fluid to the proper level, then re-inflate with dry nitrogen to the manufacturer's specified pressure.
Question 3: Which type of brake system uses a single-disc design with one puck-style actuating cylinder on each side?
- Expander tube brake
- Single-disc floating caliper brake (Correct answer)
- Multiple-disc brake
- Segmented rotor brake
Correct answer: Single-disc floating caliper brake
A single-disc floating caliper brake uses one rotor disc and a caliper that floats to apply equal pressure from both sides with pistons.
Question 4: What causes brake fade on aircraft disc brakes during repeated hard stops?
- Low hydraulic fluid viscosity
- Excessive heat buildup reducing friction between pads and disc (Correct answer)
- Air in the brake lines
- Worn brake pressure seals
Correct answer: Excessive heat buildup reducing friction between pads and disc
Brake fade occurs when excessive heat reduces the coefficient of friction between the brake pads and disc, decreasing stopping effectiveness.
Question 5: The minimum allowable disc thickness for aircraft brakes is specified in the:
- FAR Part 23
- Aircraft Type Certificate Data Sheet
- Component Maintenance Manual or Aircraft Maintenance Manual (Correct answer)
- AC 43.13-1B only
Correct answer: Component Maintenance Manual or Aircraft Maintenance Manual
The minimum disc thickness limit is found in the applicable Component Maintenance Manual (CMM) or Aircraft Maintenance Manual (AMM) for that specific aircraft and brake assembly.
Question 6: What is the function of the torque links (scissors) on a nose gear oleo strut?
- To limit strut extension travel
- To prevent strut rotation while allowing vertical movement (Correct answer)
- To connect the steering actuator to the wheel
- To provide shimmy dampening
Correct answer: To prevent strut rotation while allowing vertical movement
Torque links (scissors links) connect the upper and lower strut cylinders to prevent rotation while allowing the strut to extend and compress freely.
ACS Landing Gear & Brake Systems 1
What is the primary purpose of an oleo strut in aircraft landing gear?