M11.11

Question 1

Why are hydraulics used?

Answer 1

To activate or move heavy loads

Question 2

What is the units for force?

Answer 2

Newtons

Question 3

How is pressure calculated?

Answer 3

Force
——-
Area

Question 4

What is the unit for pressure?

Answer 4

Pascals

Question 5

What does one pascal also equal?

Answer 5

One newton per square meter

Question 6

What is hydraulic pressure normally measured in?

Answer 6

Bar or psi

Question 7

What is one bar equal to in psi?

Answer 7

14.5 psi

Question 8

If an aircraft operates at 3,000 psi, what is the amount of pressure in bar?

Answer 8

207 bar

Question 9

What is hydrostatic pressure?

Answer 9

Pressure produced by static fluids

Question 10

What is hydrodynamic pressure?

Answer 10

Pressure produced by moving liquids

Question 11

In a series of pipe work where would the high pressure be?

Answer 11

On the outside of the bends

Question 12

What type of oil is made from natural substances?

Answer 12

Mineral oil

Question 13

What type of oil is man made?

Answer 13

Synthetic oil

Question 14

What colour is mineral oil?

Answer 14

Red

Question 15

What type of oil can be mixed together?

Answer 15

Mineral oil

Question 16

What colour is synthetic oil?

Answer 16

Violet

Question 17

What type of oil cant you mix?

Answer 17

Synthetic oil

Question 18

What does hygroscopic mean?

Answer 18

If a fluid has the tendency to absorb water

Question 19

What type of oil is harmful to humans?

Answer 19

Synthetic oil

Question 20

What is another word for a seal?

Answer 20

Packing

Question 21

What happens if a seal comes in contact with the wrong hydraulic oil?

Answer 21

It will tend to increase in size

Question 22

What are seals normally made from?

Answer 22

Rubber or Teflon

Question 23

Where are static seals used?

Answer 23

Steady or pulsating pressure occurs

Question 24

Where are dynamic seals used?

Answer 24

Where stroking or rotational movement occur

Question 25

What are baffle plates used for?

Answer 25

To ensure there is a positive fluid supply to the system

Question 26

Where is the drain plugs located on a reservoir?

Answer 26

At the lowest point

Question 27

Why is the reservoir pressurised?

Answer 27

To keep a positive supply and to prevent foaming, evaporation, and cavitation

Question 28

What are the two methods for pressurising the reservoir?

Answer 28

Hydraulic pressure or air pressure

Question 29

What must you do when you want to work on the reservoir?

Answer 29

Depressurise the system

Question 30

Where is the depressurisation valve located?

Answer 30

At the ground service panel

Question 31

What is an accumulator?

Answer 31

A device with stored potential energy to exert a force

Question 32

What is hydro-pneumatic accumulators a combination of?

Answer 32

Hydraulic fluid and gas

Question 33

What are hydraulic reservoirs pressurised to?

Answer 33

50psi

Question 34

What is meant by pre-charging?

Answer 34

When a boost pump increase fluid pressure as it enters the pump

Question 35

What time of pump is most commonly used?

Answer 35

Engine-driven pump

Question 36

What type of pump is a engine-driven pump?

Answer 36

A variable displacement pump

Question 37

In an event of a fire, What is installed in the engine driven pump?

Answer 37

Fire shut off valve to stop flow of hydraulic fluid

Question 38

What colour system is the electric pump used on?

Answer 38

Blue

Question 39

When do electric pumps start automatically?

Answer 39

When the engines start

Question 40

What type of pump is the electric pump?

Answer 40

A variable displacement pump

Question 41

How are electric pumps cooled?

Answer 41

By air or hydraulic fluid

Question 42

How are the air driven pumps activated?

Answer 42

When the engine driven pump can’t maintain pressure or by flight crew

Question 43

What type of pump is a air driven pump?

Answer 43

A variable displacement pump

Question 44

How is the RAT deployed?

Answer 44

By the flight crew

Question 45

What type of pump is inside of the RAT?

Answer 45

Variable displacement pump

Question 46

How long does the RAT take to deploy?

Answer 46

Less than a second

Question 47

What are filters used for?

Answer 47

Used to remove FOD from air or fluid systems

Question 48

What can filters be made from?

Answer 48

- metal - plastic - paper

Question 49

When would the filter bypass open?

Answer 49

When the filter is clogged and caused a pressure increase

Question 50

What is the mechanical visitation that a filter is clogged?

Answer 50

A red button pops out

Question 51

What is meant by high pressure distribution?

Answer 51

The process for moving pressurised fluid from pumps to users

Question 52

What is the job of a check valve?

Answer 52

Checks that flow is in the correct direction and prevents back flow

Question 53

What does the priority valve do?

Answer 53

It priorities the more important systems if there is a large demand

Question 54

What does the low pressure distribution do?

Answer 54

It combines all of the return lines back to the reservoir

Question 55

What must there be to operate the hydraulic pumps?

Answer 55

Fuel otherwise there wouldn’t be any coolant

Question 56

What is swaging?

Answer 56

A repair sleeve on a pipe that can’t be removed

Question 57

What are the different classification of hoses?

Answer 57

Low, medium, high

Question 58

What’s the inside of a hose made from?

Answer 58

Teflon

Question 59

Wha is the protective cover on hose made from?

Answer 59

Steel wire

Question 60

Hose fittings are always?

Answer 60

Disconnectable

Question 61

Where does pressurised filling of the hydraulic system take place?

Answer 61

The service panel

Question 62

Where is a sampling valve located?

Answer 62

On the HP manifold

Question 63

What is the hydraulic fluid sampled for?

Answer 63

Water contamination and fluid performance

Question 64

What would a low air pressure fault in the reservoir lead to?

Answer 64

Cavitation

Question 65

How is the engine driven pump output regulated?

Answer 65

By the wobble plate

Question 66

What must you do to hydraulic system if it starts to overheat?

Answer 66

Completely shut it down