Hyds

Question 1

What is hydraulic actuation?

Answer 1

Transmission of force through the medium of liquid.

Question 2

Advantages of using hydraulics compared to mechanical methods

Answer 2

Greater transmission of power.
Reduce pilot fatigue.
Less strength required.
Easier routing of parts.
Variations of speed.
Smooth and steady movements.

Question 3

Units of pressure

Answer 3

Force per unit area

Question 4

What is pascals law?

Answer 4

If a force is applied to a liquid in a confined space, pressure will be transmitted equally, without reduction, throughout the liquid and will react at right angles to all confining spaces.

Question 5

What are the principles of hydraulic actuation?

Answer 5

It is the conversion of hydraulic energy into an output of force or torque.

Question 6

What is in a basic hydraulic system?

Answer 6

Reservoir, hand pump, 4/2 way dcv, Jack

Question 7

Purpose of a reservoir?

Answer 7

Store fluids to allow for small leaks.
Provide flow to the pump.
Accept return fluid.
Allow for Jack ram displacement.

Question 8

What are hydraulic pipes made from?

Answer 8

Aluminium alloy
Steel
Titanium

Question 9

How do you install rigid tubing?

Answer 9

They may be joined to either the end of an item, another section of rigid pipe or to a flexible hose.

Question 10

Purpose and construction of flexible hoses?

Answer 10

Used to connect stationary parts with moving parts.
Constructed of 2 components:
Fluid resistant inner tube and the reinforcing braid.

Question 11

What’s does the manufacturer put on flexible hoses so that you know it’s correctly installed?

Answer 11

Lay lines

Question 12

Reasons why you can’t use one seal for everything?

Answer 12

System pressure
Type of fluid
Metal finish and clearance
Type of motion

Question 13

Types of seal

Answer 13

V ring
U ring
Square section packing
Bonded seal

Question 14

Properties of hydraulic fluid

Answer 14

Viscosity, chemical stability and flash point.

Question 15

Types of hydraulic oil

Answer 15

Mineral and synthetic

Question 16

Two types of hydraulic oil contamination

Answer 16

Abrasive and non-abrasive

Question 17

When should hydraulic systems be sampled?

Answer 17

Routine sampling, unscheduled maintenance and suspicion of contamination.

Question 18

Synchronised circuit components

Answer 18

Flow divider
Two way restrictor
Blow back valve
Emergency selector

Question 19

Sequenced circuit components

Answer 19

Nrv
Dcv
Differential area jacks
Mechanical sequence valves
Prv special
Electrically operated sequence valves
Pilot operated check valve
One way restrictor
Pressure relief valve
Thermal relief valve

Question 20

What are the different techniques for fault finding

Answer 20

Easter egging
Automated test equipment
Built in test equipment
Proceduralization
Decision tree
Heuristic
Hypothesis

Question 21

Cautions when fault finding

Answer 21

Tunnel vision and test induced failure

Question 22

Sources of information for connecting ground power

Answer 22

Topic 1
Topic 5a2
Topic 5b1
Mam-p and d
Aesos
Aeros

Question 23

What do you check on the rig before using it?

Answer 23

Labels
Cables
Case
Face

Question 24

Where can information about gas replenishing be found?

Answer 24

Topic 1
5a2
5b1

Question 25

What is an embolism?

Answer 25

A air bubble that travels through the blood stream.

Question 26

What is adiabatic compression?

Answer 26

Gas rapidly compressed into a closed container, heat will be generated.

Question 27

Minimum retained pressure meaning?

Answer 27

Minimum amount of positive pressure allowed in the container to stop it being contaminated. For a gaseous bottle system 100psi.

Question 28

What is the equalisation of pressure?

Answer 28

50psi. Prevents an accumulator losing pressure.

Question 29

6 requirements of flying control system

Answer 29

Performance
Feedback
Accuracy
Stability
Irreversibility
Safety and reliability

Question 30

Features of an artificial feel system?

Answer 30

Forces should increase as stick displacement is increased