WorksheetsATA 29 - HYDRAULIC POWER
Total questions: 49
Worksheet time: 25mins
Hydraulic pressure can be restored by.
Compressing the fluid in a reservoir.
The use of a pressure/heat exchanger.
Compressing the air charge in an accumulator.
What is the colour of the band on a hydraulic seal?
White
Green
Yellow.
Accumulators as fitted to aircraft hydraulic systems.
Are only ever used in an emergency.
Store fluid under pressure.
Provide additional fluid if leaks occur.
When flushing hydraulic systems.
Flush with methylated spirit.
Flush with any hydraulic oil.
Flush with same hydraulic oil.
A check flow valve in a hydraulic system prevents.
Overpressure.
Reverse flow.
Pump cavitation.
A constant delivery pump has its output varied with.
Servo pressure.
Gears.
Regulators.
A hydraulic closed system is one where.
Most of the major components of the system are included in a self contained unit.
Pressure is maintained at the selector valves at all times.
There is no pressure at the selector valves when no functions are required.
What constitutes a hydraulic power pack?
Variable swashplate pump.
Reservoir, pump, selector valve, filter.
Hydraulic oil accumulator.
If an accumulator loses air pressure, there will be.
Rapid fluctuations of instruments.
Pump cavitation.
Rapid depressurisation of system.
One reason for fitting an accumulator in a hydraulic system is to.
Minimize the possibility of pump cavitation.
Absorb pressure surges.
Relieve excess pressure.
A thermal relief valve is fitted to a hydraulic system to.
Prevent a leak back of pressure.
Prevent excess temperature.
Relieve excess pressure.
A component in a hydraulic system which ensures instantaneous action when a service is selected is.
Accumulator.
Engine driven pump
Selector.
A shuttle valve is used for.
Preventing fluid loss from a leaking jack.
Maintaining fluid press when the emergency system fails.
Change over from main to auxiliary system in the case of failure.
The purpose of a mechanical sequence valve is to ensure the operation of.
Landing gear and doors.
Safety switches.
Brake anti-skid units.
A hydraulic accumulator is charged with initial air pressure of 1000 PSI. When the hydraulic system pressure of 3000 PSI is reached, the air pressure is.
3000 PSI.
4000 PSI.
1000 PSI.
Hydraulic reservoirs are pressurized to.
Provide a reserve of stored energy.
Minimize the possibility of pump cavitation.
Maintain a constant fluid level.
In aircraft hydraulic systems, it is permissible to use.
Any fluid of the same specific gravity.
Any hydraulic fluid available.
Only the specified fluid.
A thermal relief valve.
Senses fluid temperature change.
Provides cooling for the fluid
Senses fluid pressure.
Hydraulic systems are normally flushed with.
Methylated spirits.
Any clean hydraulic fluid
The same type of fluid as used in the system.
Hydraulic hand-pump fluid supply is taken from.
The bottom of the reservoir.
A stack pipe higher than the normal level.
A tap into a convenient return line.
To enable a hydraulic system to operate two components requiring different pressures.
A pressure regulating valve is used.
A pressure reducing valve is used.
A pressure relief valve is used.
A Skydrol hydraulic fluid seal would be made of.
Synthetic rubber.
Natural rubber.
Butyl rubber, ethylene propylene or Teflon.
Synthetic hydraulic fluid subjected to overheating is high in.
Acidity.
Alkalinity.
Viscosity.
A normal hydraulic system will.
Show pressure and source of hydraulics
Show fluid temperature and quantity.
illuminate a light in the cockpit when the system is ready
The control of hydraulically powered emergency electrical generator frequency is by.
Restriction valve
Angle of swashplate
IDG
Hydraulic systems normally operate at.
1800 PSI
300 PSI
3000 PSI
A fixed volume axial pump contains the following rotating parts.
Drive Shaft, Swash Plate & Cylinder Block
Swash Plate & Valve Block
Drive Shaft, Swash Plate & Valve Block
The purpose of a non-return valve is to.
Direct fluid to the hydraulic actuator
Isolate one component from another
Restrict the movement of components
Before checking the initial pressure in the hydraulic accumulator.
All air must be bled from the system
The fluid pressure must be released
The reservoir must be checked for correct level
Hand pumps are normally single cylinder double acting because of the.
Piston ram displacement
Two NRVS fitted
Relief valve
Hand pumps in hydraulic systems are normally.
Single acting
Low pressure
Double acting
Hydraulic operations are also almost
98 percent efficient
95 percent efficient
100 percent efficient
Liquids are able to do this because they are almost
Incompressible
Compressible
Flexible
The selector valves of the open center hydraulic system are always connected in ____ with each other.
Series
Parallels
Combines
Immediately after disconnecting, all hydraulic lines and fittings should be
Clean and storage
Clean and lubricate
Capped or Plugged
Pressurizing of reservoir assures ______ at high altitudes when low atmospheric pressures are encountered.
A positive flow of fluid to the pump(s)
Keep warm up of fluid
A stable of fluid level
Appropriate must be specifically designated for the type of hydraulic fluid in use.
Seals, gaskets, and valves
Seals, gaskets, and pumps
Seals, gaskets, and hoses
The most widely used type of hydraulic system used in aviation is the
Open- center hydraulic system
Closed- center hydraulic system
Neither of the above
The type of hydraulic fluid used most in commercial jet transport aircraft is
Phosphate esters- based
Polyalphaolefins- based
Minerals- based
Basic hydraulic system consist of:
A pump, reservoir, check valve selector valve actuator ,direction valve
A pump, reservoir, check valve selector valve actuator and filter
A pump, reservoir ,direction valve, check valve, pressure relives valve ,selector valve ,actuator and filter
The hydraulic pack system is:
A compact unit consists of an electric pump, a reservoir, valves, filters and pressure relief valve all in one assembly
A compact unit consists of EDP, a reservoir, valves, filters and pressure relief valve
A compact unit consists of an electric pump, a reservoir, valves and pressure relief valve all in one assembly
If the contamination is suspected on hydraulic system:
Fluid should be sampled to check
Fluid should be drained and refill
Fluid should be replaced with samples taken before and after maintenance procedure
Non-pressurized reservoirs are used in aircraft ;
Violent maneuvers,
Do not flight at high altitudes
Do not flight at high altitudes and located in the pressurized area of the aircraft
Where the filters are located in hydraulic system:
In pressure line and in return line
In pressure line, in return line and in the pump case drain line
In pressure line and in the pump case drain line
Hydraulic reservoir can be pressurized by:
Ambient air
Bleed air taken from compressor of the engine or hydraulic system pressure
Bleed air taken from compressor of the engine or ambient air
Electrical driven pump installed on aircraft for:
Cargo operation only
Used in emergencies
Used in emergencies or during ground operation when engines are not running
In some aircraft, the RAT automatically deploys when:
The main hydraulic pressure system fails and/or electrical system malfunction occurs
EDPs and electric pumps failure
Lost of electricals power
Does the PTU transfer any fluid from one system to the other:
Yes it does
Yes it does one litter
No it does not
The main purpose of shuttle valve is to:
Isolate the emergency system.
Isolate the from an alternate
Isolate the normal system from an alternate or emergency system.
