Airframe Mechanic Certification Hydraulic and Pneumatic Power 3

Question 1

What happens to hydraulic fluid viscosity as temperature increases?

Accepted Answer

Viscosity decreases

Answer

Hydraulic fluid becomes thinner (less viscous) as temperature rises, which can affect sealing effectiveness and pump efficiency.

Question 2

A hydraulic power pack is BEST described as:

Accepted Answer

A self-contained unit with pump, reservoir, and controls for a specific subsystem

Answer

A hydraulic power pack is a self-contained unit integrating a pump, reservoir, filter, and associated controls to power a specific aircraft subsystem.

Question 3

When bleeding a hydraulic system, the purpose is to:

Accepted Answer

Expel trapped air to ensure solid, responsive actuator operation

Answer

Bleeding removes air pockets that cause spongy or sluggish actuator response because air is compressible unlike hydraulic fluid.

Question 4

Skydrol hydraulic fluid is classified as:

Accepted Answer

A phosphate ester-based fire-resistant fluid

Answer

Skydrol is a phosphate ester-based, fire-resistant hydraulic fluid widely used in commercial transport aircraft.

Question 5

What is the function of a hydraulic fuse?

Accepted Answer

To automatically shut off flow if a downstream line ruptures and flow exceeds a preset rate

Answer

A hydraulic fuse senses excessive flow caused by a downstream rupture and closes to isolate the failed section, preserving fluid for the rest of the system.

Airframe Mechanic Certification Practice Test

Airframe Mechanic Certification Practice Test

Airframe Mechanic Certification Hydraulic and Pneumatic Power 3