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
withdrawing fluid from the system from 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 which restrict the reverse fluid flow
A pilot reports the right brake on an aircraft is spongy when then the brake pedal is depressed in a normal manner. The probable cause is
air in the brake hydraulic system
Aside from an external leak in the line, what will cause parking brakes to creep continually to the OFF position?
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 reinflated to correct pressure?
To allow the tube to position itself correctly inside the tire
The metering pins in oleo shock strut serve to
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 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 brake linings. How is equal pressure on both sides of the disk assured?
By allowing the caliper to float to automatically equalize as pressure is applied to the rotor
If it determined that spongy brake action is not caused by air in the brake system, what is the next most likely cause?
Deteriorated brake hose
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 (3000 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 a sidewall of a tube type tire is a
slippage mark
When bleeding aircraft brakes, one of the indications that the air has been purged from the system is
firm brake pedals
Overinflated aircraft tires may cause damage to the
wheel flange
Debooster valves are used in brake systems to
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
inserting, removing or changing the location of washers or spacers at the centre pivotal point of the scissor torque links
On a air valve core stem, what indicates high pressure type
embossed letter ‘H’
The primary purpose for balancing aircraft wheel assemblies is to
prevent heavy spots and reduce vibration
Power boost brake systems are used on aircraft that have
high landing speeds
On all aircraft equipped with retractable landing gear, some means must be provided to
extend the landing gear if the normal operating mechanism fails
An automatic damping action occurs as the steer damper if for any reason the flow of high pressure fluid is removed from the
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 privately owned or operated is considered
preventative 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 slow the 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
Internal leakage in a brake cylinder unit can cause
fading brakes
A sleeve, spacer or bumper ring is incorparated in a landing gear oleo shock strut to
limit the extension stroke
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
The pressure source for power brakes is
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 the parking brake when the 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
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 manufacturers service manual
The purpose of a relief valve in a brake system is to
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 wheels can be termed as having
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 temp changes
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
What is the function of a cam incorporated in a nose gear shock strut?
Straightens the nose wheel
Extension of an oleo strut is measured to determine the
proper operating position of the strut
Debooster cylinders are used in braking systems primarily to
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
strut should be removed, disassembled and reinspected
A high speed aircraft tire with a sound core 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
worn brake linings
The correct inflation pressure of an aircraft tire can be obtained from
the aircraft service manual
What should be checked when a shock strut bottoms during a hard 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 brakes and noting that the brakes 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
foreign particles stuck in the master cylinder compensating port
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
The hydraulic packing seals used in a landing gear shock strut are
used only with a specific type of fluid
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
A close inspection of the fusible plug reveals the core has experienced some deformation. What is the appropriate maintenance procedure?
Replace all fusible plugs
Chines are used on some aircraft nose wheel tires to help
deflect water away from the fuselage
The best safeguards against heat buildup in aircraft tires are
short ground rolls, slow taxi speeds, minimum braking and proper tire inflation
The fusible plugs installed in some aircraft wheels will
melt at a specified elevated temp
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 logbook
How long should you wait after a flight before checking the tire pressure?
At least 2 hours (3 hours in hot weater)
What is the minimum amount of time to wait for a tire to cool before checking the tire pressure?
3 hours
Excessive wear in the centre of the tread of an aircraft tire is an indication of
overinflation
When servicing an empty shock strut with fluid, the strut should be completely compressed and extended several times to ensure
proper packing ring seating and removal of air bubbles
In shock struts, chevron seals are used to
prevent oil from escaping
On most aircraft, the oil level of an air and oil shock strut is checked by
releasing the air and seeing the oil is to a certain level of the filler plug
A pilot reports, the brake pedals have excessive travel. A probable cause is
lack of fluid in the brake system
A pilot reports, the brake pedals have excessive travel. A probable cause is
brake rotors have worn
When will a continuous horn provide a warning in the cockpit?
When the throttle is retarded and the gear is not down and locked
An electric motor used to raise and lower a landing gear would most likely be a
split field series-wound motor
When installing a chevron-type seal in an aircraft hydraulic cylinder, the open side of the seal should face
the up direction of fluid pressure
Nose gear centring cams are used in many retractable landing gear systems. The primary purpose of the centring device is to
centre 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
a source for additional hydraulic power when heavy demands are placed on the system
A hydraulic system referred to as a ‘power block’ system will
have all hydraulic power components in one unit
What is the advantage of having a hydraulic ‘power pack’ system?
Reduces weight
A flexible hose identified as MIL-H-8788 will have a stripe running through the length of the hose. This strip is
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
a blue strip 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
micronic filter
The purpose of an orifice check valve is to
restrict flow in one direction and allow free flow in the other
A special bolt in a landing gear attachment requires a torque value of 440 inch pounds. How many foot pounds are required?
36.6 ft lbs
To protect seals from damage when installed over a threaded section, the threaded section should be
covered with a suitable sleeve
