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22 Cards in this Set
- Front
- Back
- 3rd side (hint)
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What are the two basic types of hydraulic fluids that are used in modern aircraft? |
Mineral base fluid and phosphate ester base fluid |
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What kind of filter is a micronic filter |
Special paper element |
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Does the main hydraulic pump takes it's fluid from the bottom of the reservoir or from the standpipe? |
From the standpipe |
Which is a safety measure because if the system should fail all the fluid will go overboard but some will still be left in the standpipe |
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Why are some hydraulic reservoirs pressurized? |
Because the aircraft fly at a certain altitude that has limited supply of atmospheric pressure to supply the pumps |
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What is a double action pump? |
A pump that supplies fluid in both directions with movement of the pump handle |
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Why do engine driven hydraulic pumps have a shear section in their drive couplings? |
As a safety measure so it will break to disconnect the pump from the engine and preventing further damage |
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What does an unloading valve do in a hydraulic system? |
Acts like a pressure regulator and controls system pressure by shifting the pump outlet fluid from the pressurized system back into the reservoir when system pressure is too high. |
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What is the purpose of an accumulator in an aircraft hydraulic system? |
Holds pressure in a hydraulic fluid system until it will be necessary to be used |
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What is the purpose of an orifice check valve in an aircraft hydraulic system |
Allows pressure to flow in one direction through the valve and restricts the flow in the opposite direction |
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Where are line disconnect fittings normally located in an aircraft hydraulic system? |
Where the engine driven pumps connect to the hydraulic system |
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What is meant by a single action hydraulic actuating cylinder? |
A linear actuating cylinder that uses hydraulic fluid under pressure to move the piston in one direction, the Piston is returned by a spring |
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What is the sauce of the compressed air that is used in a medium pressure on pneumatic system and a turbine engine power aircraft |
Bleed air from the engine compressor stages |
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What kind of device is used to control the speed of movement of the piston in pnuematic actuator? |
Variable orifice |
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Why do most high pressure pneumatic systems include a moisture separator? |
To separate the air from the moisture before it can freeze and block the system |
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What is the difference between an open center selector valve and a close center selector valve? |
Open center selector valves are installed in series and close center selector valves are installed in parallel |
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What is used to flush a hydraulic system that uses skydrol hydraulic fluid? |
Trichloroethylene |
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What is used to flush a hydraulic system that uses mineral base hydraulic fluid |
Naphtha , varsol or Stoddard solvent |
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Where can you find the type of hydraulic fluid that is required for a particular aircraft? |
On the placard of the system reservoir or the maintenance manual of the aircraft |
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What is used to remove phosphate Ester base hydraulic fluid from aircraft tires? |
Soap and water |
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What must be done to the lines that are disconnected when servicing an aircraft hydraulic system? |
They must be covered with the appropriate cap or plug, never use masking tape or other type of adhesive tape |
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What are two ways aircraft hydraulic reservoirs may be pressurized? |
By an aspirator in the fluid return line or with bleed air from the engine compressors |
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Why do some hydraulic pressure gauges have a snubber installed between them and the hydraulic pump? |
To keep the gauge from fluctuating |
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