Questions - Aircraft Landing Gear Systems

Fill in the Blanks

1. Name the three basic arrangements of landing gear used in aircraft:
_________________ _________________ _________________

2. Parasite drag caused by landing gear can be reduced by the addition of _________________ , or _________________.

3. Most single engine aircraft use a non shock absorbing landing gear made from _________________ , _________________, or _________________ .

4. To keep the shock strut and wheels aligned, most shock struts are equipped with _________________ , and _________________.

5. Nose gear shock struts have a _________________ to keep the gear aligned when the aircraft takes off and the shock strut fully extend.

6. The alignment of a main wheel in the vertical plain is called _________________.

7. The electric/hydraulic landing gear system found in many Cessna and Piper aircraft is called a _________________.

8. The _________________ lowers the landing gear if the main power system fails.

9. The proper functioning of a landing gear system and components can be checked by performing a _________________. This is also known as _________________ the gear.

10. Nose wheel vibration is controlled through the use of a _________________.

11. The inner wheel halve of a wheel used on a high performance aircraft is likely to have one or more _________________.

12. All aircraft axle nuts must be installed and _________________ in accordance with the airframe manufacturer’s maintenance procedures.

13. Overheating of the wheel bearings could be caused by a _________________ and results in a _________________ tint to the metal surface.

14. Brinelling is caused by _________________. It appears as _________________ in the bearing cup raceway.

15. Pushing the _________________ of the right rudder pedal activates the brake on the _________________ main wheel.

16. The _________________ transfers the motions of the pistons to the stack of _________________ and _________________ to slow the rotation of the wheel.

17. The _________________ is the latest iteration of the multiple disc brake.

18. The three brake actuating systems used are _________________, _________________ and _________________.

19. Power brake systems use the _________________ as the source of power to apply the brakes.

20. The auto brake system is used to stop the wheels automatically after _________________ this prevents the wheels from rotating when retracted in the wheel wells.

21. The anti‐skid system not only detects wheel _________________, it also detects when wheel skid is .

22. Maximum braking efficiency exists when the wheels are decelerating at a maximum rate but are not _________________.

23. Brake systems with master cylinders may be bled by _________________ or _________________ bleeding methods.

24. A flat spot on a tire is the result of the tire _________________ on the runway surface.

25. Operation on a grooved runway can cause an aircraft tire tread to develop shallow _________________ shaped cuts.

True or False

1. Most aircraft with a tricycle landing gear use differential braking for steering during ground operations. TRUE/FALSE

2. When more than two wheels are attached to a landing gear strut, the attaching mechanism is known as a bogie. TRUE/FALSE

3. Landing gear shock struts are filled with air and synthetic turbine engine oil. TRUE/FALSE

4. During taxi operations the air in the tires and the hydraulic fluid in the shock strut combine to smooth out bumps. TRUE/FALSE

5. To check the fluid level of most shock struts, the strut needs to be deflated and fully compressed. TRUE/FALSE

6. Most smaller aircraft use a powerpack gear retraction system while large aircraft use a hydraulic landing gear retraction system. TRUE/FALSE

7. Sequence valves are often operated mechanically and priority valves control gear component timing via hydraulic volume adjustments. TRUE/FALSE

8. Some aircraft use a mechanical emergency release system that unlocks the uplocks and the gear will free fall, while others use a pneumatic power system to lower the gear when the main system fails. TRUE/FALSE

9. Proximity sensors are used for gear position safety switches on many smaller single engine aircraft. TRUE/FALSE

10. The most common display for the landing gear being up and locked is an illuminated green light. TRUE/FALSE

11. Aircraft equipped with a hydraulic nose wheel steering system utilize the steering cylinders as shimmy dampers. TRUE/FALSE

12. Wheels for modern aircraft use a one piece design which provides superior strength and ease of tire installation. TRUE/FALSE

13. The two pieces of a two piece aircraft wheel are identical and could be used on both the inside as outside of the wheel assembly. TRUE/FALSE

14. Aircraft technicians should be careful when they approach or remove a tire. The high internal pressure of the tire can create a catastrophic failure that could be lethal to the technician. TRUE/FALSE

15. In a fixed disk brake system (Cleveland) the brake caliper and linings adjust their position in relationship to the disc. TRUE/FALSE

16. Dual disc brakes are used on large transport category aircraft that use hydraulic systems to operate the brake systems. TRUE/FALSE

17. In general small light aircraft use independent brake systems. A master cylinder provides the hydraulic pressure. TRUE/FALSE

18. The brake accumulator is an emergency source of power for the brake system. TRUE/FALSE

19. Autobrake systems on large aircraft do not use the anti skid system to control wheel skid. TRUE/FALSE

20. In order to bleed the power brake system of a large transport category aircraft the hydraulic system needs to be pressurized. TRUE/FALSE

21. Type III tires are common general aviation tires, Type V tires are high performance tires found on jet aircraft. TRUE/FALSE

22. Traditional aircraft tires are bias ply tires while modern large aircraft utilize radial tires. TRUE/FALSE

23. When checking tire pressure wait at least 30 minutes after a typical landing to ensure the tire has cooled to ambient temperature. TRUE/FALSE

24. Small pieces of rock or debris can be removed with a probing tool or screwdriver while the tire is on the aircraft and inflated. TRUE/FALSE

25. Under inflation could be evident from excessive wear on the outside of the tire threads. TRUE/FALSE

Knowledge Application Questions

1. What is used to service an air/oil landing gear shock strut?
_____________________________________________________________________

2. What regular inspection should be made of the exposed portion of a landing gear strut?
_____________________________________________________________________

3. What is the purpose of main landing gear torque links and arms?
_____________________________________________________________________

4. What power sources are normally used to retract landing gear systems?
_____________________________________________________________________

5. What type of nosewheel steering is provided on small aircraft?
_____________________________________________________________________

6. What unit prevents nosewheel vibration?
_____________________________________________________________________

7. What is the purpose of power brake debooster cylinders?
_____________________________________________________________________

8. Name the common types of brake systems used on aircraft?
_____________________________________________________________________

9. What must be accomplished before inspecting a wheel brake system for hydraulic leaks?
_____________________________________________________________________

10. What prevents a split wheel from leaking air through the inner and outer mating surfaces, or the wheel assembly?
_____________________________________________________________________

11. What is the most important maintenance action for safe, long, aircraft tire service?
_____________________________________________________________________

12. What are the effects of under inflation on tires?
_____________________________________________________________________

13. When should a landing gear retraction check be accomplished?
_____________________________________________________________________

14. What is the indication of excessive heating of a wheel bearing?
_____________________________________________________________________

15. What is the purpose of an anti‐skid system?
_____________________________________________________________________

Multiple Choices Questions

1. Exposure to and/or storage near which of the following is considered harmful to aircraft tires?
1. Low humidity.
2. Fuel.
3. Oil.
4. Ozone.
5. Helium.
6. Electrical equipment.
7. Hydraulic fluid.
8. Solvents.

a. 1,2,3,5,7,8
b. 2,3,4,6,7,8
c. 2,3,4,5,6,7,8

2. What would be the effect if the piston return spring broke in a brake master cylinder?
a. The brake travel would become excessive.
b. The brakes would become spongy.
c. The brakes would drag.

3. In brake service work, the term "bleeding brakes" is the process of
a. replacing small amounts of fluid in reservoir.
b. withdrawing air only from the system.
c. withdrawing fluid from the system for the purpose of removing air that has entered the system.

4. To prevent a very rapid extension of an oleo shock strut after initial compression resulting from landing impact,
a. various types of valves or orifices are used which restrict the reverse fluid flow.
b. the air is forced through a restricted orifice in the reverse direction.
c. the metering pin gradually reduces the size of the orifice as the shock strut extends.

5. A pilot reports the right brake on an aircraft is spongy when the brake pedal is depressed in a normal manner. The probable cause is
a. the hydraulic master cylinder piston return spring is weak.
b. air in the brake hydraulic system.
c. the hydraulic master cylinder piston is sticking.

6. Aside from an external leak in the line, what will cause parking brakes to creep continually to the OFF position?
a. Insufficient hydraulic fluid in the reservoir.
b. Glazed brake linings.
c. An internal leak in the master cylinder.

7. Why do most aircraft tire manufacturers recommend that the tubes in newly installed tires be first inflated, fully deflated, and then reinflated to the correct pressure?
a. To eliminate all the air between the tube and the inside of the tire.
b. To allow the tube to position itself correctly inside the tire.
c. To test the entire assembly for leaks.

8. The metering pins in oleo shock struts serve to
a. retard the flow of oil as the struts are compressed.
b. meter the proper amount of air in the struts.
c. lock the struts in the DOWN position.

9. After performing maintenance on an aircraft's landing gear system which may have affected the system's operation, it is usually necessary to
a. make an operational check with the aircraft on jacks.
b. re-inspect the area after the first flight.
c. conduct a flight test.

10. Why do tire and wheel manufacturers often recommend that the tires on split rim wheels be deflated before removing the wheel from the axle?
a. To relieve the strain on the wheel retaining nut and axle threads.
b. As a safety precaution in case the bolts that hold the wheel halves together have been damaged or weakened.
c. To remove the static load imposed upon the wheel bearings by the inflated tire.

11. The braking action of a cleveland disk brake is accomplished by compressing a rotating brake disk between two opposite brake linings. How is equal pressure on both sides of the rotating disk assured?
a. By allowing the brake rotor to float to automatically equalize as pressure is applied to the rotor.
b. By allowing the brake linings to automatically equalize as pressure is applied to the rotor.
c. By allowing the caliper to float to automatically equalize as pressure is applied to the rotor.

12. If it is determined that spongy brake action is not caused by air in the brake system, what is the next most likely cause?
a. Deteriorated flexible hoses.
b. Internal leakage in the master cylinder.
c. Worn brake lining.

13. Many brake types can be adapted to operate mechanically or hydraulically. Which type is not adaptable to mechanical operation?
a. Expander tube type.
b. Single disk spot type.
c. Single servo type.

14. A brake debooster valve is installed in systems where the high pressure of the hydraulic system (3000 psi) is used to operate brakes
a. that are used on aircraft having high landing speeds.
b. that are designed to work with lower pressure.
c. that are used in conjunction with an antiskid system.

15. A stripe or mark applied to a wheel rim and extending onto the sidewall of a tube type tire is a
a. wheel weight reference mark..
b. wheel-to-tire balance mark.
c. slippage mark.

16. When bleeding aircraft brakes, one of the indications that the air has been purged from the system is
a. full brake pedal travel.
b. partial brake pedal travel.
c. firm brake pedals.

17. Overinflated aircraft tires may cause damage to the
a. wheel flange.
b. brake linings.
c. wheel hub.

18. Debooster valves are used in brake systems primarily to
a. reduce the pressure and release the brakes rapidly.
b. reduce brake pressure and maintain static pressure.
c. ensure rapid application and release of the brakes.

19. The repair for an out of tolerance toe in condition of main landing gear wheels determined not to be the result of bent or twisted components consists of
a. shimming the axle in the oleo trunnion.
b. placing shims or spacers behind the bearing of the out of tolerance wheel or wheels.
c. inserting, removing, or changing the location of washers or spacers at the center pivotal point of the scissor torque links.

20. An embossed letter "H" on an air valve core stem
a. indicates high-pressure type.
b. indicates hydraulic type.
c. is the manufacturer's trademark.

21. The primary purpose for balancing aircraft wheel assemblies is to
a. prevent heavy spots and reduce vibration.
b. reduce excessive wear and turbulence.
c. distribute the aircraft weight properly.

22. Power boost brake systems are used on aircraft that have
a. high landing speeds.
b. low normal hydraulic system pressure.
c. more than one brake assembly per axle.

23. On all aircraft equipped with retractable landing gear, some means must be provided to
a. extend the landing gear if the normal operating mechanism fails.
b. retract and extend the landing gear if the normal operating mechanism fails.
c. prevent the throttle from being reduced below a safe power setting while the landing gear is retracted.

24. An automatic damping action occurs at the steer damper if for any reason the flow of high pressure fluid is removed from the
a. outlet of the steer damper.
b. replenishing check valve.
c. inlet of the steer damper.

25. What is the purpose of the torque links attached to the cylinder and piston of a landing gear oleo strut?
a. Limit compression stroke.
b. Maintain correct wheel alignment.
c. Hold the strut in place.

26. The removal, installation, and repair of landing gear tires by the holder of a private pilot certificate on an aircraft owned or operated is considered to be
a. a violation of the Federal Aviation Regulations.
b. preventive maintenance.
c. a minor repair.

27. Aircraft brakes requiring a large volume of fluid to operate the brakes generally
a. use power brake control valves.
b. do not use brake system accumulators.
c. use independent master cylinder systems.

28. What is one effect a restricted compensator port of a master cylinder will have on a brake system?
a. The reservoir will be filled by reverse flow.
b. The restriction will cause slow release of the brakes.
c. The brakes will operate normally.

29. When an air/oil type of landing gear shock strut is used, the initial shock of landing is cushioned by
a. compression of the fluid.
b. the fluid being forced through a metered opening.
c. compression of the air charge.

30. Internal leakage in a brake master cylinder unit can cause
a. the pedal to slowly creep down while pedal pressure is applied.
b. fading brakes.
c. slow release of brakes.

31. A sleeve, spacer, or bumper ring is incorporated in a landing gear oleo shock strut to
a. limit the extension stroke.
b. limit the extension of the torque arm.
c. reduce the rebound effect.

32. The purpose of a sequence valve in a hydraulic retractable landing gear system is to
a. prevent heavy landing gear from falling too rapidly upon extension.
b. provide a means of disconnecting the normal source of hydraulic power and connecting the emergency source of power.
c. ensure operation of the landing gear and gear doors in the proper order.

33. The pressure source for power brakes is
a. the main hydraulic system.
b. a master cylinder.
C. the power brake reservoir.

34. Which statement is true with respect to an aircraft equipped with hydraulically operated multiple disk type brake assemblies?
a. There are no minimum or maximum disk clearance checks required due to the use of self compensating cylinder assemblies.
b. No parking brake provisions are possible for this type of brake assembly.
c. Do not set parking brake when brakes are hot.

35. What type of valve is used in the brake actuating line to isolate the emergency brake system from the normal power brake control valve system?
a. A shuttle valve.
b. A bypass valve.
c. An orifice check valve.

36. When servicing an air/oil shock strut with MIL-5606 the strut should be
a. collapsed and fluid added at the filler opening.
b. partially extended and fluid added at the filler opening.
c. fully extended and fluid added at the filler opening.

37. Instructions concerning the type of fluid and amount of air pressure to be put in a shock strut are found
a. in the aircraft manufacturer's service manual.
b. in the aircraft operations limitations.
c. on the airplane data plate.

38. The purpose of a relief valve in a brake system is to
a. prevent the tire from skidding.
b. reduce pressure for brake application.
c. compensate for thermal expansion.

39. Aircraft tire pressure should be checked
a. using only a push on stick-type gauge having 1-pound increments.
b. at least once a week or more often.
c. as soon as possible after each flight.

40. If the extended longitudinal axis of the main landing gear wheel assemblies intersects aft of the aircraft, the wheels can be termed as having
a. negative camber.
b. toe out.
c. toe in.

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