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WorksheetsBlock 8
Total questions: 25
Worksheet time: 13mins
Which section of a turbine engine provides high pressure bleed air to an air cycle machine for pressurization and air conditioning?
Low or high pressure compressor
Compressor inlet
C-D inlet compressor duct
The Air
Hydraulic fluid reservoirs are sometimes designed with a standpipe in one of the
outlet ports in order to assure emergency supply of fluid. The outlet port with the
standpipe in it furnishes fluid to the
emergency pump when the fluid supply to the normal system has been depleted
emergency pump at any time it is required
normal system power pump
The unit in a hydraulic system that requires a certain action to be completed before
another action can begin is called a
check valve
sequence valve
snubber valve
What is the viscosity of hydraulic fluid?
The increase in volume of a fluid due to temperature change
The fluid's ability to resist oxidation and deterioration for long periods
The internal resistance of a fluid which tends to prevent it from flowing
Heat exchanger cooling units are required in some aircraft hydraulic systems because
of?
fluid flammability
high pressures and high rates of fluid flow
the high heat generated from braking
A hydraulic pump is a constant-displacement type if it
produces an unregulated constant pressure
produces a continuous positive pressure
delivers a uniform rate of fluid flow
Extrusion of an O-ring seal is prevented in a high-pressure system by the use of a
backup ring on the side of the O-ring next to the pressure
U-ring on the side of the O-ring away from the pressure
backup ring on the side of the O-ring away from the pressure
If it is necessary to adjust several pressure regulating valves in a hydraulic system,
what particular sequence, if any, should be followed?
Units most distant from the hydraulic pump should be adjusted first
- Units with the highest pressure settings are adjusted first
Units are independent of each other, and therefore, no particular sequence is
necessary
How many of these seals are used with petroleum-base hydraulic fluids?
Natural rubber, Ethylene-propylene
Neoprene, Buna-N
Natural rubber, Butyl rubber
Which is a characteristic of synthetic-base hydraulic fluid?
Low moisture retention
High flash point
Low flash point
Using a hand pump, pressure of 100 psi has been built up in a hydraulic system. The
hand pump piston is 1 inch in diameter. A 1/2-inch line connects the hand pump to an
actuating cylinder 2 inches in diameter. What is the pressure in the line between the
hand pump and the actuator?
100 psi
150 psi
200 psi
Which of the following lists only desirable properties of a good hydraulic fluid that
has chemical stability?
High viscosity, low flash point, high fire point.
High flash point, low viscosity, low fire point.
Low viscosity, high flash point, high fire point.
If an aircraft hydraulic system requires mineral-base hydraulic fluid, but phosphate
ester-base hydraulic fluid is used, what will be the effect on the system?
No effect.
System will be contaminated, fluids will not blend, and the seals will fail.
System will be contaminated, fluids will not blend, but there will be no seal problem.
To protect seals from damage when installed over a threaded section, the threaded
section should be
coated with a heavy grease.
covered with tape.
covered with a suitable sleeve.
To check the air charge in a hydraulic accumulator,
reduce all hydraulic pressure, then observe the reading on the accumulator air gauge.
observe the first reading on the hydraulic system gauge while operating a component in
the system
read it directly from the auxiliary pressure gauge.
Pneumatic systems utilize
thermal valves
relief valves.
shuttle valves.
The component in the hydraulic system that is used to direct the flow of fluid is the
check valve.
orifice check valve.
selector valve.
Characteristics of MIL-H-5606 hydraulic fluid are
light purple color, phosphate ester base, fire resistant, uses butyl rubber seals.
blue color, will burn, uses natural rubber seals.
red color, petroleum base, will burn, uses synthetic rubber seals.
An aircraft pneumatic system, which incorporates an engine-driven multistage
reciprocating compressor, also requires
an oil separator.
a surge chamber.
a moisture separator.
A crossflow valve which is designed to bypass fluid from one side of an actuating
cylinder to the other side, under certain conditions, may be found in some aircraft
installed in the
flap overload system.
engine cowl flap system.
landing gear system.
The air that is expended and no longer needed when an actuating unit is operated in a
pneumatic system is
exhausted or dumped, usually overboard.
returned to the compressor.
charged or pressurized for use during the next operating cycle.
A common cause of slow actuation of hydraulic components is
cold fluid.
restricted orifices.
internal leakage in the actuating unit.
One of the distinguishing characteristics of an open-center selector valve used in a
hydraulic system is that
fluid flows through the valve in the OFF position.
fluid flows in three directions in the ON position.
a limited amount of fluid flows in one direction and no fluid flows in the opposite
direction
Some hydraulic systems incorporate a device which is designed to remain open to allow
a normal fluid flow in the line, but closed if the fluid flow increases above an
established rate. This device is generally referred to as a
hydraulic fuse.
flow regulator.
metering check valve.
In a typical high-pressure pneumatic system, if the moisture separator does not vent
accumulated water when the compressor shuts down, a likely cause is a
saturated chemical dryer.
saturated chemical dryer.
malfunctioning solenoid dump valve.
