Airframe Mechanic Certification Hydraulic and Pneumatic Power 5

Question 1

A shuttle valve in a hydraulic system is used to:

Accepted Answer

Automatically select the higher of two pressure sources to supply a critical component

Answer

A shuttle valve connects a component to whichever of two supply sources (normal or emergency) has the higher pressure, ensuring continuous supply.

Question 2

What determines the maximum safe working pressure of a hydraulic hose assembly?

Accepted Answer

The manufacturer's published rated working pressure for that hose specification

Answer

Each hose assembly has a manufacturer-specified maximum working pressure that must equal or exceed the system's operating pressure.

Question 3

Fluid in an aircraft hydraulic reservoir is maintained above the minimum level primarily to:

Accepted Answer

Prevent pump cavitation and allow for thermal expansion of fluid

Answer

Adequate fluid level prevents the pump from drawing air (cavitation) and provides volume for fluid that expands when heated during operation.

Question 4

An aircraft pneumatic system using engine bleed air would MOST likely use bleed air from which compressor stage?

Accepted Answer

An intermediate or high-pressure compressor stage depending on engine power setting

Answer

Bleed air is tapped from intermediate or high-pressure compressor stages, with automatic selection between stages to maintain adequate pressure across the flight envelope.

Question 5

What is the function of a priority valve in a hydraulic system?

Accepted Answer

To ensure that flight-critical systems receive pressure before non-essential systems when pressure is low

Answer

A priority valve closes off non-critical hydraulic consumers when system pressure drops, reserving available pressure for flight-critical systems like flight controls.

Airframe Mechanic Certification Practice Test

Airframe Mechanic Certification Practice Test

Airframe Mechanic Certification Hydraulic and Pneumatic Power 5