Flashcards on Aircraft Hydraulic and Pneumatic Systems

Aircraft Hydraulic and Pneumatic Systems: A Student Guide

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What are the two basic types of hydraulic fluid used in modern aircraft?

Mineral-base fluid and phosphate-ester-base fluid.

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Aircraft Hydraulic Systems

20 cards

Card 1

Question: What are the two basic types of hydraulic fluid used in modern aircraft?

Answer: Mineral-base fluid and phosphate-ester-base fluid.

Card 2

Question: What kind of filter is a micronic filter?

Answer: A filter with a special paper element.

Card 3

Question: From where does the main hydraulic pump normally take its fluid?

Answer: From a standpipe in the reservoir.

Card 4

Question: From where does the emergency hydraulic pump take its fluid?

Answer: From the bottom of the reservoir.

Card 5

Question: Why are some hydraulic reservoirs pressurized?

Answer: To ensure fluid is supplied to pump inlets at high altitude where atmospheric pressure is insufficient.

Card 6

Question: What is the difference between an open-center selector valve and a closed-center selector valve?

Answer: Open-center valves are installed in series and allow fluid to flow through the center when idle (acting as pump unloading). Closed-center valves are i

Card 7

Question: What solvent is used to flush a hydraulic system that uses Skydrol (phosphate-ester) fluid?

Answer: Trichloroethylene (TCE).

Card 8

Question: What solvents are used to flush a hydraulic system that uses mineral-base hydraulic fluid?

Answer: Naphtha, Varsol, or Stoddard solvent.

Card 9

Question: What is used to remove phosphate-ester (Skydrol) fluid from aircraft tires?

Answer: Soap and water.

Card 10

Question: What must be done to hydraulic lines that are disconnected during servicing?

Answer: They must be capped with the correct fluid line cap or plug; never use masking tape or other adhesive tape.