Aircraft Landing Gear Systems Flashcards
Exposure to and/or storage near which of the following is considered harmful to aircraft tires?
Fuel, oil, ozone, electrical equipment, hydraulic fluid, and solvents.
What would be the effect if the piston return spring broke in a brake master cylinder?
the brakes would drag.
In brake service work, the term “bleeding brakes” is the process of what?
withdrawing fluid from the system for the purpose of removing air that has entered the system.
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 used which restrict the reverse fluid flow.
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 what?
air in the brake hydraulic system.
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.
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.
The metering pins in oleo shock struts serve to what?
retard the flow of oil as the struts are compressed.
What action should be taken whenever maintenance is performed that will affect the landing gear system performance?
the aircraft should be placed on jacks and a retraction test should be performed.
When working with high pressure, high performance tires, why is it recommended to deflate the tires when removing wheels from the axle?
to ensure safety in case of defective wheel or broken tie bolts.
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.
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.
Many brake types can be adapted to operate mechanically or hydraulically. Which type is not adaptable to mechanical operation?
Expander-tube type.
A brake debooster valve is installed in systems where the high pressure of the hydraulic system (3,000 psi) is used to operate brakes…
that are designed to work with lower pressure.
A stripe or mark applied to a wheel rim and extending onto the sidewall of a tube-type tire is a what?
slippage mark.
When bleeding aircraft brakes, one of the indications that the air has been purged from the system is what?
firm brake pedals.
Overinflated aircraft tires may cause damage to the what?
Wheel flange,
Debooster valves are used in brake systems primarily to what?
reduce the pressure and release the brakes rapidly.
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 what?
inserting, removing, or changing the location of washers or spacers at the center pivotal point of the scissor torque links.
On an air valve core stem, what indicates high-pressure type?
An embossed letter “H.”
The primary purpose for balancing aircraft wheel assemblies is to what?
prevent heavy spots and reduce vibration.
Power boost brake systems are used on aircraft that have what?
high landing speeds.
On all aircraft equipped with retractable landing gear, some means must be provided to what?
extend the landing gear if the normal operating mechanism fails.
An automatic damping action occurs at the steering damper if for any reason the flow of high-pressure fluid is removed from the what?
inlet of the steering damper.
What is the purpose of the torque links attached to the cylinder and piston of a landing gear oleo strut?
Maintain correct wheel alignment.
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 what?
preventive maintenance.
Aircraft brakes requiring a large volume of fluid to operate the brakes generally…
use power brake control valves.
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 what?
the fluid being forced through a metered opening.
Internal leakage in a brake master cylinder unit can cause what?
the pedal to slowly creep down while pedal pressure is applied.
A sleeve, spacer, or bumper ring is incorporated in a landing gear oleo shock strut to what?
limit the extension stroke.
The purpose of a sequence valve in a hydraulic retractable landing gear system is to what?
ensure operation of the landing gear and gear doors in the proper order.
The pressure source for power brakes is what?
the main hydraulic system.
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 are hot.
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.
When servicing an air/oil shock strut with MIL-5606 the strut should be what?
collapsed and fluid added at the filler opening.
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.
The purpose of a relief valve in a brake system is to what?
compensate for thermal expansion.
Aircraft tire pressure should be checked…
at least once a week or more often.
If the extended longitudinal axis of the main landing gear wheel assemblies intersects aft of the aircraft, the wheel can be termed as having what?
toe-out.
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 or away from the reservoir as temperature changes.
If an aircraft shock strut (air/oil) bottoms upon initial landing contact, but functions correctly during taxi, the most probable cause is what?
low fluid.
What is the function of a cam incorporated in a nose gear shock strut?
Straightens the nosewheel.
Extension of an oleo shock strut is measured to determine the what?
proper operating position of the strut.
Debooster cylinders are used in brake systems primarily to what?
reduce the pressure to the brake and increase the volume of fluid flow.
If a shock strut bottoms after it has been properly serviced, the what?
strut should be removed, disassembled, and inspected.
A high-speed aircraft tire with a sound cord body and bead may be recapped…
an indefinite number of times.
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 what?
worn brake linings.
The correct inflation pressure for an aircraft tire can be obtained from what?
the aircraft service manual.
What should be checked when a shock strut bottoms during a landing?
Fluid level.
How is it determined in a master cylinder brake system that all of the air has been purged from the system?
By depressing the brake and noting that the brake is firm and not spongy.
The left brake is dragging excessively on an airplane on which no recent brake service work has been performed. The most probable cause is what?
foreign particles stuck in the master cylinder compensating port.
If a brake debooster is used in a hydraulic system, its position in the system will be what?
between the brake control valve and the brake actuating cylinder.
The hydraulic packing seals used in a landing gear shock strut are what?
used only with a specific type of fluid.
Lockout deboosters are primarily pressure reducing valves that what?
allow full debooster piston travel without fluid from the high pressure side entering the low pressure chamber.
A close inspection of a fusible plug reveals the core has experienced some deformation. What is the appropriate maintenance procedure?
Replace all the fusible plugs.
Chines are used on some aircraft nose wheel tires to help what?
deflect water away from the fuselage.
The best safeguards against heat buildup in aircraft tires are what?
short ground rolls, slow taxi speeds, minimum braking, and proper tire inflation.
The fusible plugs installed in some aircraft wheels will what?
melt at a specified elevated temperature.
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.
How long should you wait after a flight before checking tire pressure?
At least 2 hours (3 hours in hot weather).
What is the minimum amount of time to wait for tires to cool before checking tire pressure?
3 hours
Excessive wear in the shoulder area of an aircraft tire is an indication of what?
underinflation.
Excessive wear in the center of the tread of an aircraft tire is an indication of what?
overinflation.
When servicing an empty shock strut with fluid, the strut should be completely compressed and extended several times to ensure what?
proper packing ring seating and removal of air bubbles.
In shock struts, chevron seals are used to what?
prevent oil from escaping.
On most aircraft, the oil level of an air and oil shock strut is checked by what?
releasing the air and seeing that the oil is to the level of the filler plug.
A pilot reports that the brake pedals have excessive travel. A probable cause is what?
lack of fluid in the brake system.
When will a continuous horn provide a warning in the cockpit?
When the throttle is retarded and gear is not down and locked.
An electric motor used to raise and lower a landing gear would most likely be a what?
split field series-wound.
When installing a chevron-type seal in an aircraft hydraulic cylinder, the open side of the seal should face what?
the direction of fluid pressure.
Nose gear centering cams are used in many retractable landing gear systems. The primary purpose of the centering device is to what?
center the nosewheel before it enters the wheel well.
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.
A fully charged hydraulic accumulator provides what?
a source for additional hydraulic power when heavy demands are placed on the system.
A hydraulic system referred to as a “power pack” system will what?
have all hydraulic power components located in one unit.
A flexible hydraulic hose identified as MIL-H-8788 will have a strip running the length of the hose. This stripe is what?
installed without excessive twisting.
An O-ring intended for use in a hydraulic system using MIL-H-5606 (mineral base) fluid will be marked with what?
a blue stripe or dot.
What condition would most likely cause excessive fluctuation of the pressure gauge when the hydraulic pump is operating?
Inadequate supply of fluid.
A filter incorporating specially treated cellulose paper is identified as a what?
Micronic filter.
The purpose of an orifice check valve is to what?
restrict flow in one direction and allow free flow in the other.
(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.
A special bolt in a landing gear attachment requires a torque value of 440 inch-pounds. How many foot-pounds are required?
36.6
