Aircraft Landing Gear Systems Flashcards
When installing a chevron-type seal in an aircraft hydraulic cylinder, the open side of the seal should face
the direction of fluid pressure.
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?
To allow the tube to position itself correctly inside the tire.
A high-speed aircraft tire with a sound cord body and bead may be recapped
an indefinite number of times.
A stripe or mark applied to a wheel rim and extending onto the sidewall of a tube-type tire is a
slippage mark
A brake debooster valve is installed in systems where the high pressure of the hydraulic system (3000 psi) is used to operate brakes
that are designed to work with lower pressure.
Many brake types can be adapted to operate mechanically or hydraulically. Which type is not adaptable to mechanical operation?
Expander-tube type
What is the purpose of a compensating port or valve in a brake master cylinder of an independent brake system?
permits the fluid to flow toward and away from the reservoir as the temperature changes.
What action, if any, should be taken when there is a difference of more than 5 pounds of air pressure in tires mounted as duals?
correct the discrepancy and enter in the aircraft records.
The pressure source for power brakes is
the main hydraulic system
An automatic damping action occurs at the steering damper if for any reason the flow of high-pressure fluid is removed from the
inlet of the steering damper
(Refer to Figure 10.) The trunnion nut on an aircraft landing gear requires a torque of 320 inch-pounds. To reach the nut, a 2-inch straight adapter must be used on an 18-inch torque wrench. How many foot-pounds will be indicated on the torque wrench when the required torque of the nut is reached?
24
The best safeguards against heat buildup in aircraft tires are
short ground rolls, slow taxi speeds, minimum braking, and proper tire inflation.
Nose gear centering cams are used in many retractable landing gear systems. The primary purpose of the centering device is to
center the nosewheel before it enters the wheel well.
How can it be determined that all air has been purged from a master cylinder brake system?
By noting whether the brake is firm or spongy.
If the extended longitudinal axis of the main landing gear wheel assemblies intersects aft of the aircraft, the wheels can be termed as having
toe-out.
What is one effect a restricted compensator port of a master cylinder will have on a brake system?
The restriction will cause slow release of the brakes.
When an air/oil type of landing gear shock strut is used, the initial shock of landing is cushioned by
the fluid being forced through a metered opening.
An O-ring intended for use in a hydraulic system using MIL-H-5606 (mineral base) fluid will be marked with
A blue stripe or dot.
The purpose of an orifice check valve is to
restrict flow in one direction and allow free flow in the other
On all aircraft equipped with retractable landing gear, some means must be provided to
extend the landing gear if the normal operating mechanism fails
Instructions concerning the type of fluid and amount of air pressure to be put in a shock strut are found
in the aircraft manufacturer’s service manual
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 shuttle valve.
Internal leakage in a brake master cylinder unit can cause
the pedal to slowly creep down while pedal pressure is applied.
The left brake is dragging excessively on an airplane on which no recent brake service work has been performed. The most probable cause is
foreign particles stuck in the master cylinder compensating port.
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
preventive maintenance.
In brake service work, the term ‘bleeding brakes’ is the process of
withdrawing fluid from the brake system for the purpose of removing air that has entered the system.
Exposure to and/or storage near which of the following is considered harmful to aircraft tires?
- Low humidity.
- Fuel.
- Oil.
- Ozone.
- Helium.
- Electrical equipment.
- Hydraulic fluid.
- Solvents.
2, 3, 4, 6, 7, 8
Aside from an external leak in the line, what will cause parking brakes to continually bleed off pressure?
An internal leak in the master cylinder.
A sleeve, spacer, or bumper ring is incorporated in a landing gear oleo shock strut to
limit the extension stroke.
What should be checked when a shock strut bottoms during a landing?
fluid level.
An electric motor used to raise and lower a landing gear would most likely be a
split field series-wound motor.
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
air in the brake hydraulic system.
Why do tire and wheel manufacturers often recommend that the tires on split rim wheels be deflated before removing the wheel from the axle?
As a safety precaution in case the bolts that hold the wheel halves together have been damaged or weakened.
On an air valve core stem, what indicates high-pressure type?
An embossed letter “H”.
A filter incorporating specially treated cellulose paper is identified as a
micronic filter
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?
By allowing the caliper to float to automatically equalize as pressure is applied to the rotor.
How long should you wait after a flight before checking tire pressure?
At least 2 hours (3 in hot weather).
Debooster valves are used in brake systems primarily to
reduce the pressure and release the brakes rapidly.
Chines are used on some aircraft nose wheel tires to help
deflect water away from the fuselage.
The fusible plugs installed in some aircraft wheels will
melt at a specified elevated temperature
A pilot reports that the brake pedals have excessive travel. A probable cause is
lack of fluid in the brake system
What is the function of a cam incorporated in a nose gear shock strut?
straightens the nosewheel.
The purpose of a relief valve in a brake system is to
compensate for thermal expansion.
A flexible hydraulic hose identified as MIL-H-8788 will have a stripe running the length of the hose. This stripe
is used to ensure that the hose is installed without excessive twisting.
Aircraft brakes requiring a large volume of fluid to operate the brakes generally
use power brake control valves.
Which statement is true with respect to an aircraft equipped with hydraulically operated multiple-disk type brake assemblies?
Do not set parking brake when brakes hot.
What condition would most likely cause excessive fluctuation of the pressure gauge when the hydraulic pump is operating?
Inadequate supply of fluid.
When servicing an air/oil shock strut with MIL-5606 the strut should be
collapsed and fluid added at the filler opening.
Overinflated aircraft tires may cause damage to the
wheel flange.
The hydraulic packing seals used in a landing gear shock strut are
used only with a specific type of fluid.
When a properly operating fusible plug has allowed a tire to deflate, the tire should be
replaced.
A special bolt in a landing gear attachment requires a torque value of 440 inch-pounds. How many foot-pounds are required?
36.6
When bleeding aircraft brakes, one of the indications that the air has been purged from the system is
firm brake pedals.
What device in a hydraulic system with a constant-delivery pump allows circulation of the fluid when no demands are on the system?
pressure regulator.
When an empty shock strut is filled with fluid, care should be taken to extend and compress the strut completely at least two times to
ensure proper packing ring seating and removal of air bubbles.
If an airplane equipped with master cylinders and single-disk brakes has excessive brake pedal travel, but the brakes are hard and effective, the probable cause is
worn brake linings.
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
inserting, removing, or changing the location of washers or spacers at the center pivotal point of the scissor torque links.
If a shock strut bottoms after it has been properly serviced, the
strut should be removed, disassembled, and inspected.
The purpose of a sequence valve in a hydraulic retractable landing gear system is to
ensure operation of the landing gear and gear doors in the proper order.
Lockout deboosters are primarily pressure reducing valves that
allow full debooster piston travel without fluid from the high pressure side entering the low pressure chamber.
If it is determined that spongy brake action is not caused by air in the brake system, what is the next most likely cause?
deteriorated flexible hoses.
Aircraft tire pressure should be checked
at least once a week or more often.
On most aircraft, the oil level of an air and oil shock strut is checked by
releasing the air and seeing that the oil is to the level of the filler plug.
What is the purpose of the torque links attached to the cylinder and piston of a landing gear oleo strut?
Maintain correct wheel alignment.
What would be the effect if the piston return spring broke in a brake master cylinder?
The brakes would drag.
Extension of an oleo shock strut is measured to determine the
proper operating position of the strut.
The primary purpose for balancing aircraft wheel assemblies is to
prevent heavy spots and reduce vibration.
The metering pins in oleo shock struts serve to
retard the flow of oil as the struts are compressed.
If a brake debooster is used in a hydraulic brake system, its position in the system will be
between the brake control valve and the brake actuating cylinder.
A hydraulic system referred to as a ‘power pack’ system will
have all hydraulic power components located in one unit.
Excessive wear in the shoulder area of an aircraft tire is an indication of
underinflation.
A fully-charged hydraulic accumulator provides
a source for additional hydraulic power when heavy demands are placed on the system.
The correct inflation pressure for an aircraft tire can be obtained from
the aircraft service manual.
To prevent a very rapid extension of an oleo shock strut after initial compression resulting from landing impact,
various types of valves or orifices are used which restrict the reverse fluid flow.
After performing maintenance on an aircraft’s landing gear system which may have affected the system’s operation, it is usually necessary to
make an operational check with the aircraft on jacks.
Power boost brake systems are used on aircraft that have
high landing speeds.
In shock struts, chevron seals are used to
prevent oil from escaping.
Excessive wear in the center of the tread of an aircraft tire is an indication of
overinflation.
If an aircraft shock strut (air/oil type) bottoms upon initial landing contact, but functions correctly during taxi, the most probable cause is
low fluid.
Debooster cylinders are used in brake systems primarily to
reduce the pressure to the brake and increase the volume of fluid flow.
A landing gear position and warning system will provide a warning in the cockpit when the throttle is
retarded and the gear is not down and locked.
