18 Landing Gear, Wheels & Brakes Practice Questions & Answers
Every Landing Gear, Wheels & Brakes practice question from the FAA A&P Airframe (AMA) Practice Test, with the correct answer and a short explanation.
Start practice test →1. During the compression stroke of an air/oil (oleo) shock strut, the energy of the landing impact is primarily absorbed by what action?
- A.Fluid forced through a metered orifice into the upper chamber✓ Answer
- B.The packing rings compressing against the polished piston wall
- C.Compressed air in the upper chamber forced through the orifice plate
- D.The torque links flexing as the piston telescopes into the cylinder
On compression, oil in the lower chamber is forced up through the orifice, whose effective area is varied throughout the stroke by the tapered metering pin, so the impact energy is converted to heat and dissipated through the strut walls. The compressed air or nitrogen acts as the spring: it limits the end of the compression stroke and cushions taxi shocks, but it is the metered fluid flow that absorbs the landing impact.
Source: FAA-H-8083-31 Aviation Maintenance Technician Handbook (Airframe), Ch. 13 (Aircraft Landing Gear Systems)Report a problem with this question
2. Before the fluid level of an air/oil shock strut is checked and replenished, what condition must the strut be in?
- A.Deflated and fully compressed, then filled to the level of the service port✓ Answer
- B.Inflated and fully extended, then filled to the level of the service port
- C.Deflated and fully extended, then filled until fluid reaches the torque links
- D.Inflated and fully compressed, then filled until fluid overflows the gland nut
The air charge must be released and the strut collapsed so that the fluid alone occupies the cylinder; filling to the level of the service (filler) port then gives the correct volume. Servicing an extended or still-charged strut leaves it short of fluid. When deflating, depress the valve core to release trapped air, then loosen the swivel nut about one turn while standing to the side of the valve, because an ejected core travels at high velocity.
Source: FAA-H-8083-31 Aviation Maintenance Technician Handbook (Airframe), Ch. 13 (shock strut servicing)Report a problem with this question
3. An air/oil shock strut serviced to the correct fluid level slowly settles to a partially compressed position while the aircraft is parked. What is the most likely cause?
- A.A leaking air valve or piston seal letting the air charge escape✓ Answer
- B.Worn torque links allowing the piston to rotate in the cylinder
- C.A centering cam holding the piston short of full extension
- D.A bent metering pin restricting fluid flow through the orifice
It is the compressed air charge, not the fluid, that holds the strut extended under the static weight of the aircraft, so a strut that will not hold extension has lost air past a leaking valve or a defective piston seal. Worn torque links and a bent metering pin produce steering or damping complaints, not a slow loss of extension, and a strut allowed to bottom out transmits landing loads directly into the airframe.
Source: FAA-H-8083-31 Aviation Maintenance Technician Handbook (Airframe), Ch. 13 (shock strut troubleshooting)Report a problem with this question
4. On many retractable-gear aircraft, how does the emergency (alternate) extension system lower the landing gear?
- A.Energizing a standby motor that overrides the normal selector valve
- B.Releasing the uplocks so gravity and air loads carry the gear down✓ Answer
- C.Venting the downlocks so springs pull the gear from the wheel wells
- D.Reversing the hydraulic pump to drive the gear down mechanically
An emergency extension system is designed to work without the normal power source, so a handle, crank, or cable release simply unlocks the uplocks and lets the gear free fall into the down-and-locked position under gravity assisted by air loads; some designs instead use a stored-pressure blow-down bottle. Because it is the last line of defense, the alternate system must be operated and verified every time the gear is swung on jacks.
Source: FAA-H-8083-31 Aviation Maintenance Technician Handbook (Airframe), Ch. 13 (emergency extension systems)Report a problem with this question
5. What is the function of the landing gear safety switch (squat switch) mounted on a main gear shock strut?
- A.It opens the gear-down circuit while the strut is extended, preventing extension in flight
- B.It closes the gear-up circuit while the strut is compressed, allowing ground retraction
- C.It closes the warning horn circuit while the strut is extended, silencing the horn
- D.It opens the gear-up circuit while the strut is compressed, preventing ground retraction✓ Answer
The safety switch is actuated by strut compression, so with the weight of the aircraft on the wheels it opens the circuit to the gear-up solenoid and inadvertent retraction on the ground is impossible. When the strut extends after lift-off the switch changes state and retraction is enabled; the same air/ground signal also gates anti-skid, auto brakes, and other systems. Many modern aircraft perform this function with proximity sensors rather than a contact microswitch.
Source: FAA-H-8083-31 Aviation Maintenance Technician Handbook (Airframe), Ch. 13 (landing gear safety switch)Report a problem with this question
6. On a typical retractable-gear airplane, under what condition does the landing gear warning horn sound?
- A.The gear is in transit and the wing flaps are fully retracted
- B.The gear is not up and locked and the throttle is advanced
- C.The gear is not down and locked and the throttle is retarded✓ Answer
- D.The gear is down and locked and the throttle is retarded
The warning circuit combines a throttle-position switch with the gear position sensing, so the horn sounds only when power is reduced for approach while the gear is still not down and locked. That logic catches the pilot who has begun a descent to land without lowering the gear, and it is one of the items verified during a landing gear retraction test.
Source: FAA-H-8083-31 Aviation Maintenance Technician Handbook (Airframe), Ch. 13 (gear warning systems)Report a problem with this question
7. In a landing gear position indicating system that uses green and red lights, what does it normally mean when all gear position lights are extinguished?
- A.The gear is down and locked in the extended position
- B.The gear is unlocked and the indicating circuit has failed
- C.The gear is retracted and locked in the up position✓ Answer
- D.The gear is in transit between the up and down positions
In the conventional scheme a green light means that gear is down and locked, a red light means unsafe or in transit, and no light at all means the gear is up and locked, so the dark panel is the normal cruise indication rather than a fault. Candidates who assume a dark panel means a failed bulb should recall that the lights are press-to-test for exactly that reason.
Source: FAA-H-8083-31 Aviation Maintenance Technician Handbook (Airframe), Ch. 13 (gear position indicators)Report a problem with this question
8. A nose wheel develops shimmy during the landing rollout. Which group of items should be checked first?
- A.A broken downlock spring, worn brake linings, and a warped disc
- B.Worn torque links, loose wheel bearings, and a weak shimmy damper✓ Answer
- C.A bent metering pin, tight wheel bearings, and an overinflated strut
- D.A seized centering cam, high tire pressure, and an overfilled strut
Shimmy is a rapid side-to-side oscillation that arises from free play in the nose gear combined with insufficient damping, so the mechanic looks for wear and looseness in the torque links and wheel bearings, wheel imbalance or low tire pressure, and a shimmy damper that is defective or low on fluid. Piston-type dampers have a fill port and must be checked for correct fluid level, while a non-hydraulic elastomer damper contains no fluid and is replaced when the rubber deteriorates.
Source: FAA-H-8083-31 Aviation Maintenance Technician Handbook (Airframe), Ch. 13 (nose wheel steering and shimmy dampers)Report a problem with this question
9. Why is the bead seat area of an aircraft wheel routinely inspected by the eddy current method?
- A.It is the most highly stressed part of the wheel and is prone to fatigue cracks✓ Answer
- B.It carries the tie bolts and must be checked for elongated bolt holes
- C.It is the only part of the wheel that a dye penetrant check cannot reach
- D.It houses the thermal plugs and must be checked for melted fusible alloy
The bead seat carries the tire load into the wheel and is the highest-stress region of the casting, which is why it is often roll-formed for strength and why fatigue cracks start there; eddy current finds those surface and near-surface cracks without disassembly, while dye penetrant is used on other areas and on many light aircraft wheels. A wheel found cracked in the bead seat is scrapped, not repaired.
Source: FAA-H-8083-31 Aviation Maintenance Technician Handbook (Airframe), Ch. 13 (aircraft wheel inspection)Report a problem with this question
10. What is the purpose of the fusible (thermal) plugs installed in the wheels of high-performance aircraft?
- A.To relieve pressure whenever the tire is inflated above its rated pressure
- B.To seal the wheel halves so a tubeless tire holds pressure at the bead
- C.To melt at a set temperature and release tire pressure before the tire bursts✓ Answer
- D.To vent gas that becomes trapped between the casing plies of the tire
A fusible plug is filled with a low-melting-point alloy that melts when brake heat soaks the wheel, deflating the tire in a controlled way instead of allowing an explosive failure. Because a melted plug is evidence of a severe overheat, the wheel is removed, the tire discarded, and the mating and adjacent wheels and brakes are inspected for heat damage. The separate overinflation safety plug and the colored sidewall awl vent perform the other functions listed.
Source: FAA-H-8083-31 Aviation Maintenance Technician Handbook (Airframe), Ch. 13 (wheels, fusible plugs)Report a problem with this question
11. Why must a power brake system be bled from the top down by gravity rather than pressure bled from the brake bleed port?
- A.Gravity bleeding is required because power brakes use a different fluid
- B.Gravity bleeding is the only method that keeps the brake reservoir full
- C.Pressure bleeding would force trapped air into the main hydraulic system✓ Answer
- D.Pressure bleeding would collapse the return springs inside the brake housing
A power brake system draws its fluid from the aircraft main hydraulic system, so pushing fluid upward from the bleed port would carry the air being purged into that system, where it would degrade every service it supplies. Master cylinder (independent) systems have no such connection and may be bled either top down or bottom up. In either case the bleeding is complete when the pedal feels firm rather than spongy, because air is compressible and fluid is not.
Source: FAA-H-8083-31 Aviation Maintenance Technician Handbook (Airframe), Ch. 13 (brake bleeding)Report a problem with this question
12. On an independent master cylinder brake system, the brakes continue to drag after the pedals are released. Which condition would cause this?
- A.Excessive clearance between the brake linings and the disc
- B.A master cylinder seal that bypasses fluid to the reservoir
- C.A broken piston return spring in the brake master cylinder✓ Answer
- D.A low fluid level in the brake system supply reservoir
If the master cylinder piston return spring is broken the piston does not return far enough to uncover the compensating port, so pressure stays trapped in the line and the linings are held against the disc. The other conditions listed reduce braking or give a soft pedal instead. Dragging is also caused by a weak brake return spring, a return pin slipping in its auto-adjuster grip, a warped disc, or air in the line that expands as it heats.
Source: FAA-H-8083-31 Aviation Maintenance Technician Handbook (Airframe), Ch. 13 (brake malfunctions, dragging brakes)Report a problem with this question
13. How is an aircraft anti-skid system best described?
- A.An electrical system using solenoid-operated brake actuators at each wheel
- B.A hydraulic system using pressure-sensitive metering valves at each brake
- C.An electrohydraulic system using wheel speed sensors and control valves✓ Answer
- D.A pneumatic system using air pressure to modulate the brake pistons
Anti-skid is electrohydraulic: wheel speed transducers feed an electronic control unit that commands torque-motor anti-skid control valves, one per brake, which modulate hydraulic brake pressure. When an impending skid is sensed the valve releases pressure and then reapplies it at a slightly lower value, giving maximum braking for the surface while reducing tire wear and blowouts. An inoperative system can be switched off, leaving normal braking available.
Source: FAA-H-8083-31 Aviation Maintenance Technician Handbook (Airframe), Ch. 13 (anti-skid systems)Report a problem with this question
14. What does the touchdown protection function of an anti-skid system prevent?
- A.Brake application until the flight crew arms the anti-skid switch
- B.Brake application whenever the gear selector is placed in the up position
- C.Brake application until the wheels spin up and weight is on the wheels✓ Answer
- D.Brake release when one wheel of a pair turns slower than its mate
If braking were applied to a non-rotating wheel at touchdown the tire would be scrubbed flat or blown out, so the anti-skid control valve dumps brake pressure back to return until the squat switch shows weight on wheels and the wheel speed sensors show the wheels have spun up. A minimum wheel speed signal backs up the squat switch, and paired wheels are deliberately assigned to different sources so one signal failure cannot defeat the protection.
Source: FAA-H-8083-31 Aviation Maintenance Technician Handbook (Airframe), Ch. 13 (touchdown protection)Report a problem with this question
15. How does the locked wheel protection function of an anti-skid system operate?
- A.It shuts the entire anti-skid system off when a wheel stops rotating
- B.It releases pressure to all braked wheels when a wheel stops rotating
- C.It applies extra pressure to a wheel that has stopped rotating
- D.It fully releases brake pressure to a wheel that has stopped rotating✓ Answer
A wheel that has stopped rotating while the aircraft is still moving is skidding, so the control unit commands that wheel's anti-skid valve fully open to return and lets the wheel spin back up; braking on the remaining wheels is unaffected. The comparison is made between paired wheels, and on one transport-category design pressure is relieved when one wheel of an inboard-outboard pair turns 25 percent slower than its mate. Anti-skid is not available for parking or emergency braking.
Source: FAA-H-8083-31 Aviation Maintenance Technician Handbook (Airframe), Ch. 13 (locked wheel protection)Report a problem with this question
16. Excessive tread wear in the center of an aircraft tire, with the shoulders comparatively unworn, indicates what condition?
- A.The tire has been operated in an overinflated condition✓ Answer
- B.The tire has been operated with the brakes constantly dragging
- C.The tire has been operated in an underinflated condition
- D.The wheel has excessive camber built into the axle assembly
An overinflated tire bulges at the crown so the load is carried on the center of the tread, wearing it first, while an underinflated tire flattens and wears the shoulders. Inflation pressure is set from the aircraft maintenance data with the weight of the aircraft on the wheels, never from the sidewall marking or the tire's appearance, and about 3 hours should elapse after landing so the tire cools to ambient before the pressure is checked.
Source: FAA-H-8083-31 Aviation Maintenance Technician Handbook (Airframe), Ch. 13 (tire inspection and inflation)Report a problem with this question
17. One tire of a dual-wheel installation is found severely underinflated. What is the correct action?
- A.Inflate the low tire and return the pair to service
- B.Remove both tires of that installation from service✓ Answer
- C.Remove the low tire only and return its mate to service
- D.Inflate the low tire and re-check its pressure later
When one tire of a dual installation loses pressure its mate has been carrying the full load of the pair, so both tires are considered to have been overloaded and overheated and both must be removed. The same rule applies when one tire of the pair has been run flat or has suffered an overheat, and any tire subjected to an aborted takeoff, severe braking, or a melted fusible plug is removed from service regardless of appearance.
Source: FAA-H-8083-31 Aviation Maintenance Technician Handbook (Airframe), Ch. 13 (tire removal criteria)Report a problem with this question
18. Why must a high-pressure tire be completely deflated before the wheel is removed from the axle or the wheel tie bolts are loosened?
- A.The inflated tire makes the assembly too heavy to lift off the axle
- B.A cracked wheel half or failed tie bolt could let the assembly burst apart✓ Answer
- C.The trapped air prevents the bead from breaking loose from the wheel
- D.The residual pressure strains the axle threads as the nut is removed
The reason is personal safety: a wheel half that is cracked or a tie bolt that has failed can let the pressurized assembly separate explosively the moment it is disturbed, and the stored energy is enough to be fatal. For the same reason the tire is deflated before the valve core is removed, the assembly is approached from the front or rear rather than from the side, nitrogen and never oxygen is used for inflation, and a safety cage is used when inflating above the recommended pressure.
Source: AC 43.13-1 Acceptable Methods, Techniques, and Practices, Ch. 9, Sec. 1 (tire maintenance and personal safety)Report a problem with this question
Practice questions based on the Aviation Mechanic Airman Certification Standards (FAA-S-ACS-1), 14 CFR parts 43, 65, and 91, and the FAA Aviation Maintenance Technician Handbook—Airframe (FAA-H-8083-31). This site is not affiliated with or endorsed by the Federal Aviation Administration. This bank covers the AIRFRAME written test only; the General and Powerplant written tests and the oral and practical tests are separate. Torque values, cable tensions, inflation pressures, servicing quantities, wear limits, and repair criteria always come from the manufacturer's current maintenance data, the structural repair manual, and the applicable airworthiness directives — never from a practice test. Confirm current eligibility and testing requirements with the FAA before you test. About the A&P mechanic certificate →