AMT Hydraulics and Pneumatics 2

Question 1

What is the purpose of a hydraulic system relief valve?

Accepted Answer

To limit maximum system pressure and prevent overpressure damage

Answer

To filter contaminants from the fluid

Answer

To regulate fluid temperature during operation

Answer

To maintain constant flow rate to actuators

Question 2

Which hydraulic fluid is used in most modern commercial transport aircraft?

Accepted Answer

Skydrol (purple phosphate ester)

Answer

MIL-H-5606 (red mineral oil)

Answer

MIL-H-83282 (red fire-resistant)

Answer

Ethylene glycol-based fluid

Question 3

In a hydraulic system, what does a check valve do?

Accepted Answer

Allows fluid flow in one direction only

Answer

Regulates pressure to a fixed value

Answer

Measures volumetric flow rate

Answer

Controls the speed of actuator movement

Question 4

What type of pump is most commonly used as the main hydraulic pump on large transport aircraft?

Accepted Answer

Variable-displacement axial piston pump

Answer

Gear pump

Answer

Vane pump

Answer

Centrifugal pump

Question 5

What is the function of a hydraulic accumulator?

Accepted Answer

To store a small volume of pressurized fluid for emergency use and dampen pressure surges

Answer

To convert hydraulic pressure into electrical power

Answer

To separate water contamination from hydraulic fluid

Answer

To control the direction of actuator movement

Question 6

When bleeding a hydraulic system, what is the primary goal?

Accepted Answer

Purge all air from the lines to prevent spongy actuator response

Answer

Remove excess hydraulic fluid from the reservoir

Answer

Replace the hydraulic fluid with fresh fluid

Answer

Increase system operating pressure to specification

Question 7

A selector valve in a hydraulic system is used to:

Accepted Answer

Direct fluid flow to the appropriate actuator port to control direction of movement

Answer

Limit maximum system pressure

Answer

Filter particulate contamination from the fluid

Answer

Convert mechanical energy into hydraulic pressure