1) A pressure control relay in a hydraulic pump is Report

energised to the run position

used to prevent anything happening until there is hydraulic pressure

de-energised to start the pump

2) A constant delivery pump has its output varied with Report

regulators

gears

servo pressure

3) A variable angled pump starts at Report

half way position

minimum stroke

maximum stroke

4) A check flow valve in a hydraulic system prevents Report

pump cavitation

reverse flow

overpressure

5) A duplex seal consist of Report

a square section rubber ring within a steel washer

a hard rubber square section ring with a soft rubber square section inner ring

a rubber 'T' section ring sandwiched between two Teflon rings

6) When is an hydraulic de-pressurising valve energised? Report

When selected on

When selected off

When there is sufficient hydraulic pressure available

7) A fixed volume axial pump contains the following rotating parts Report

Drive Shaft, Swash Plate & Valve Block

Swash Plate & Valve Block

Drive Shaft, Swash Plate & Cylinder Block

8) An hydraulic closed system is one where Report

pressure is maintained at the selector valves at all times

there is no pressure at the selector valves when no functions are required

most of the major components of the system are included in a self contained unit

9) What constitutes a hydraulic power pack?. Report

Variable swashplate pump

Reservoir, pump, selector valve, filter

Hydraulic oil accumulator

10) If an accumulator loses air pressure there will be Report

rapid depressurisation of system

pump cavitation

rapid fluctuations of instruments

11) A marker number on a pipe indicates Report

the thickness of the wall on the pipe

the specification of the pipe throughout the pipe run

the type of fluid used to pressure test the pipe

12) One reason for fitting an accumulator in an hydraulic system is to Report

minimize the possibility of pump cavitation

absorb pressure surges

relieve excess pressure

13) A thermal relief valve is fitted to an hydraulic system to Report

prevent a leak back of pressure

prevent excess temperature

relieve excess pressure

14) A component in a hydraulic system which ensures instantaneous action when a service is selected is Report

accumulator

engine driven pump

selector

15) A shuttle valve is used for Report

preventing fluid loss from a leaking jack

maintaining fluid press when the emergency system fails

change over from main to auxiliary system in the case of failure

16) Restrictor valves in an hydraulic system are used to Report

Restrict the rate of pressure build up

Control the rate of system operation

Limit the maximum pressure

17) The purpose of a mechanical sequence valve is to ensure the operation of. Report

landing gear and doors

safety switches

brake anti-skid units

18) The purpose of a non-return valve is to Report

direct fluid to the hydraulic actuator

restrict the movement of components

isolate one component from another

19) The end fittings on a NRV are normally different to Report

facilitate bleeding of the system

allow a full flow from the valve

prevent incorrect installation

20) A hydraulic accumulator is charged with initial air pressure of 1000 PSI. When the hydraulic system pressure of 3000 PSI is reached, the air pressure is Report

4000 PSI

3000 PSI

1000 PSI

EASA Questions Module 11 Set 15: Hydraulic Power

Set 1: Theory of flight

Set 2: Airframe Structures

Set 3: Aeroplanes-Fuselage

Set 4: Cabin Pressurisation

Set 5: Instruments

Set 6: Avionic system

Set 7: Avionic system

Set 8: Navigation

Set 9: Electrical Power

Set 10: Electrical System

Set 11: Battery

Set 12: Equip & Furnishing

Set 13: Fire Protection

Set 14: Fuel Systems

Set 15: Hydraulic Power

Set 16: Ice & Rain

Set 17: Flight Controls

Set 18: Flight Controls_1

Set 19: Landing Gear

Set 20: Lights

Set 21: Oxygen

Set 22: Pneumatic

Set 23: Water & Waste