Hydraulics Airframe Final AMT
If the main gears are located inline under the fuselage and the outrigger wheels are used to support the wings then this must be...
A tandam type.
The three main functions of the control unit are to: Name all 3
A.) Generate electrical signal B.) Regulate the brake pressure C.) Prevent accidental application of brakes
The three principle components of an anti-skid system are the: Name all 3
A.) Wheel-speed censors B.) Control Unit (Anti-skid computer) C.) Control valves
A unit that transforms hydraulic pressure into linear motion is called...
Actuator
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 consist of doing what? (How do you adjust toe-in toe-out?)
Adding or removing washer at the center pivot point of the scissors.
Chattering of the hydraulic pump during operation is an indication of...
Air
(8309) 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.
When a pilot reports an anti-skid system or brake malfunction the mechanic should first verify...
Air in the system (this could also mean low fluid)
An oleo strut is often referred to as a...
Air- oil
(8347) What is the function of a cam incorporated in a nose gear shock strut...
Align the wheel when it is being brought up into the aircraft.
Which statement about fluid is correct?
All fluids readily transmit pressure.
(8351) A high speed aircraft tire with a sound chord body and bead can be recapped...
An in-defiant number of times.
A stall occurs when an airplane reaches a critical...
Angle of attack.
Force is what variable that makes up pressure, what is the other?
Area
(8343) Aircraft tire pressure should be checked...
At minimum once a week.
(8355) 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 the brake is firm and not spongy.
(8340) When servicing an oleo strut with 5606 (hydraulic fluid) the strut should be...
Collapsed and fluid added at the filler opening.
What hydraulic system pump needs a specific amount of fluid each time the shaft turns?
Constant displacement pump
The tail wheel type landing gear arrangement is also called...
Conventional
(8364) What action if any should be taking when there is a difference of more than 5.Ibs in air pressure in tires mounted as duals...
Correct the discrepancy but make sure you enter it into the aircraft records.
(8316) 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.
(8338) Which statement is true with respect to when a aircraft equipped with hydraulically operated multi-disk type break assemblies...
Do not set the parking break when they are hot.
Most common type of handpump?
Double action
The installation of a new hydraulic line should be made with enough bends to allow the tube to...
Expand and contract with temperature changes and also to absorb vibrations
When changing a Cleveland brake assembly ensure the tire is deflated before removing the tire. (True or False)
False, we don't remove the tire.
What's the most generally used constant displacement pump for medium pressure systems?
Gear type
What are the perks of a relief valve?
Generally used as a back-up rather than a control device.
Tail wheel aircraft are susceptible to an abrupt movement called
Ground loop.
What are the desired properties of good hydraulic fluid: Name 2
High flash point Low viscosity
On all aircraft equipped with retractable landing gear, some means must be provided to...
If you can retract it you must to have an alternate means to get them back down., incase of system failure.
Chimes are used on some aircraft nose wheel tires to help...
Keep the water away from the fuselage.
(8329) Whats the purpose of the torque links?
Keeps the lower strut cylinder aligned.
Hydraulic actuators which produce straight-line movement are known as _________ actuators.
Linear
If an aircrafts constant pressure hydraulic system cycles more frequently than usual and no fluid leakage can be detected the most probable cause is...
Low accumulator preload
(8346) If an aircraft shock strut bottoms upon initial landing contact but functions correctly during taxing...
Low fluid (air in the strut).
Power brakes are operated using pressure from...
Main hydraulic system.
An aircraft pneumatic system which incorporates an engine-driven multistage reciprocating compressor also requires
Moisture seperator
Know the AN fitting picture.
Must have a shoulder on it
What is one advantage of a piston type hydraulic motors over electric motors.
No fire.
When all landing gear is up and locked what lights will illuminate?
None
Whats the most commonly used seal to prevent internal and external leakage?
O-ring.
The most commonly used shock absorber used for aircraft...
Oleo
Excessive wear on the center of a tire is indication of...
Overinflation.
Quick disconnect cufflinks in a hydraulic system are used to...
Prevent loss of fluid.
Whats the primary function of the flap overload valve?
Prevents the flaps from being lowered at airspeeds which would impose excessive structural loads
What color is 5606
Red
What light will illuminate any time the landing gear in not locked?
Red light
(8322) Debooster valves are used in brake systems primarily to...
Reduce the pressure and release the brakes rapidly.
(8370) On most aircraft the oil level of an air and oil shock struct is checked by...
Releasing the air and seeing if the oil is to the level of the filler plug
Before removing the filler cap of a pressurized hydraulic reservoir, in order to service the system, you must...
Relieve the pressure.
(8368) When servicing an empty shock strut with fluid the strut should be completely compressed and extended several times to...
Remove air bubbles and proper packing ring seating.
The metering pin in the Oleo shock strut are for what purpose?
Retard the flow of oil as the struts are compressing.
When working with high pressure (high performance tires) why is it recommended to deflate the tires when removing wheels from the axel.
Safety.
The component in a hydraulic system used to direct the flow of fluid...
Selector valve
Which valve directs pressurized fluid to one end of an actuating cylinder and simultaneously directs return fluid to the reservoir?
Selector valve
(8341) Instructions concerning the type of fluid or air pressure to put in a shock strut are found...
Service manual.
(8353) The correct inflation pressure for an aircraft tire can be obtained from...
Service manual.
When hydraulic system pressure control and relief units fail to function properly, how are most systems protected against overpressure?
Shear shaft
To achieve maximum braking the wheels should just start to_______but not________.
Slip, skid
A stripe or mark applied to the wheel rim and extending onto the sidewall is called a...
Slippage mark.
The Mach airspeed warning can only be silenced by...
Slowing the aircraft down.
The most popular form of landing gear found on Cessna type aircraft...
Spring steel
High performance aircraft generally use what to warn the pilot of an impending stall?
Stick shaker.
Oleo strut absorbs the landing impact with the fluid and taxi shocks with...
The air.
(8337) The pressure source for power brakes is...
The main hydraulic system
Which coupling nut should be selected for use with 1/2 inch aluminum oil lines which are to be assembled using flared tube ends and standard AN nuts, sleeves, and fittings?
They are in increments of 16, so 8/16 is 1/2.
Why do most aircraft tire manufactures recommend inflating the tube slowly, then deflating the tube, and then reinflating the tube
To allow the tube to position itself correctly.
Why do we cap lines after we remove a component?
To prevent contamination
(8366) Excessive wear on the shoulder is a sign of...
Under inflation.
Hydraulic component that kicks in and kicks out...
Unloader valve
(8358) The hydraulic packing seals used on landing gear shock strut are...
Used only with a specific type of fluid.
over-inflating aircraft tires may cause damage to...
Wheel flange.
The stream line faring used to enclose the wheels are called...
Wheel pant
(8372) When will continuous horn provide a warning in the cockpit?
When the throttle is retarded and gear is not down and locked.
Some small aircraft use what kind of light for Up? and a green light for down.
White light
(8352) If an airplane equipped with master cylinder in a single disk break has excessive brake pedal travel but the brakes are hard and effective...
Worn brake lining.
(8360) A close inspection of a fusible plug reveals the core has experienced some type of damage what is the appropriate maintenance procedure?
You have to replace all of fusible plugs, you can't just replace one.
Pressure is used to determine force per unit of area and it is expressed as...
psi
Characteristics of synthetic based hydraulic fluid? Name all 4
1.) High flashpoint 2.) Wide operating temperatures 3.) Purple 4.) Nonflammable
Which characteristics apply to aircraft hydraulic systems:
1.) Minimum maintenance requirements 2.) Light weight 3.) Simple to inspect
Two types of hydraulic fluid being used today...
1.) Phosphate ester-based (Skydrol) 2.) Mineral-based (5606)
Excluding lines, which components are required to make up a simple hydraulic system? Name 5
1.) Pump 2.) Reservoir 3.) Check valve 4.) Selector valve 5.) Actuator
(8360) The best safe guards against heat build up in aircraft tires: Name all 4
1.) Short ground rolls 2.) Slow taxi speeds 3.) Minimum braking 4.) Proper tire inflation
Two thing hydraulic system accumulators do in the hydraulic system
1.) Supplement or store for emergency use 2.) Accept pressure spikes
(8310) 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.
How is the air in a hydraulic accumulator prevented from entering the fluid system?
By physical separating the air chamber from the oil chamber with a flexible or removable separator.
What are the 3 types of landing gear arrangements?
1.) Conventional 2.) Tricycle 3.) Tandem
Characteristics of petroleum based hydraulic fluid (5606): Name 2
1.) Flammable under normal conditions 2.) Red
Scratches are acceptable in hydraulic tubes providing they are less than what percent of the tube diameter.
10%
although dents in the heel of a bend are not permissible they are acceptable in the remainder of the hydraulic tube providing they are less than what percent of the tube diameter
20%
A hydraulic accumulator is charged with an air preload of 1000 psi when a hydraulic system pressure of 3000 psi is developed the pressure on the air side of the accumulator will be
3000
What type of selector valve is the most commonly used in hydraulic systems?
4 port
Flexible lines must be installed with a slack of_______of the length
5-8%
Which valve allows fluid to flow uninhibited in one direction but no flow in the other?
Check valve
The braking action of a Cleveland disk brake is accomplished by compressing a rotating brake disk between two opposing brake lines how is equal pressure on both sides of the rotating disk assured?
Cleveland brake floats.
Generally, the first step in removing an accumulator from an aircraft is to...
Discharge the preload.
When a brake fails to completely release after the pressure is removed, it is said to be...
Dragging.
Cunno filters are not cleanable and should not be replace at regular intervals (True or False)
False
When the aircraft is on the ground, the landing gear configuration horn will operate is a throttle is retarded to approximately 60%. (True or False)
False, because it is on the ground.
(8320) When bleeding aircraft brakes, one of the indications that the air has been purged from the system is...
Firm brake pedals.
Hydraulic valves may be divided into two types...
Flow and pressure control
One of the distinguishing characteristics of an open center selector valve...
Fluid flows through the valve in the off position
(8356) 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.
(8326) Power boost brake systems are used on aircraft that have...
High landing speeds.
It is necessary to adjust several regulating valves in a hydraulic system, what particular sequence should be followed if any?
Highest pressure setting first
Hydraulic system ops check of a aircraft indicated that the wing flaps cannot be lowered using the main hydraulic system but can be lowered using the back up emergency system...
Low fluid in the reservoir
Teflon hose that has developed a permanent set from being exposed to high pressure or temperature should
Not be straightened out
Two types of shock absorbing systems...
Oleo and Spring steel
What type of valve in an aircraft hydraulic system prevents fluid to flow freely in one direction but restricts it in the other direction?
Orifice check valve
What valve is used to control the rate of movement of hydraulically operated mechanisms?
Orifice check valve
Metal fluid tubing lines are assigned by wall thickness and
Outside diameter and in 16 increments.
To check the air charge in a hydraulic accumulator
Reduce all of the hydraulic pressure first and then read it off of the gauge.
(8349) Debooster cylinders are used in brake systems primarily to...
Reduce the pressure to the brakes and increase the volume of fluid flow.
Unloading valves are used with many engine-driven hydraulic pumps to...
Relieve pressure at the pump (by kicking-out).
The unit in a hydraulic system that requires a certain action to be completed before another action can begin...
Sequence valve
The hydraulic component that automatically directs fluid from either the normal source or the emergency source to an actuating cylinder is called a...
Shuttle valve
Which of the hydraulic fluids is adversely affected by humidity?
Skydrol
Name two types of hose material that is compatible with Skydrol: Name 2
Teflon and butle
(8318) 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.
Hydraulic fluid reservoirs are sometimes designed with a standpipe at one of the outlet ports in order to assure emergency supply of fluid, the outlet port with the standpipe in it reverse fluid to...
The normal system
(8333) When an air oil type of landing gear shock strut is used the initial shock of landing is cushioned by...
The oil/fluid being forced through a metering opening.
What happens to the output of a constant displacement hydraulic pump when the hydraulic system pressure regulator diverts the fluid from the system to the reservoir?
The output pressure reduces but the volume remains the same.
(8334) Internal leakage in a brake master cylinder unit can cause.
The pedal to slowly creep down while pedal pressure is applied.
(8332) 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.
What safety device is usually located between the driving unit and hydraulic pump drive shaft?
The shear section.
Certain amount of slack must be left on a flexible hose during installation because when under pressure
The tube expands.
Which valve when installed in a hydraulic system will have the highest pressure setting?
Thermal relief valve.
(8331) Aircraft brakes requiring a large volume of fluid to operate the brakes generally...
Use power brake control valve.
(8307) In brake service work, the term "bleeding the brakes" is the process of...
Withdrawing fluid from the system for the purpose of removing air that has entered the system.
(8352) 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 braking effectiveness of a skidding tire nearly...
0%
(8357) 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.
What is the color of AN aluminum fitting? What would be the color of a steel fitting?
Blue, because it is made of aluminum. Black, for steel
(8375) Nose gear centering cams are used in any retractable landing gear systems, the primary purpose of the centering device is to...
Center the nose wheel before it enter the wheel well.
