Test on Aircraft Hydraulic and Pneumatic Systems

Question 1: Does a snubber installed between a hydraulic pressure gage and the hydraulic pump prevent the gage from fluctuating?

A. Ano

B. Ne

Explanation: The snubber keeps the gage from fluctuating.

Question 2: Is it acceptable to cap disconnected hydraulic lines with masking tape when servicing an aircraft hydraulic system?

A. Ano

B. Ne

Explanation: Disconnected hydraulic lines must be capped with the correct fluid line cap or plug. Masking tape or other types of adhesive tape should never be used for this purpose.

Question 3: What is the primary purpose of an orifice check valve in an aircraft hydraulic system?

A. It allows full flow of fluid in one direction through the valve but restricts the flow in the opposite direction.

B. It controls system pressure by shifting pump outlet fluid back into the reservoir when pressure is high.

C. It holds pressure on the hydraulic fluid in the system using compressed air or nitrogen.

D. It keeps the pressure gauge from fluctuating due to pump pulsations.

Explanation: An orifice check valve is designed to allow full flow of fluid in one direction through the valve while restricting the flow in the opposite direction, as stated in the study materials.

Question 4: According to the provided study materials, what are the two basic types of hydraulic fluid used in modern aircraft?

A. Mineral base fluid

B. Skydrol hydraulic fluid

C. Phosphate ester base fluid

D. Synthetic hydrocarbon fluid

Explanation: The study materials state: 'What are the two basic types of hydraulic fluid that are used in modern aircraft? Mineral base fluid and phosphate ester base fluid.'

Question 5: High-pressure pneumatic systems include a moisture separator to remove water from the air before it can freeze and block the system.

A. Ano

B. Ne

Explanation: Most high-pressure pneumatic systems include a moisture separator because when the pressure of the stored air is reduced, the temperature drops, which can freeze any water in the air. The separators remove this water to prevent it from freezing and blocking the system.