M15.9

Question 1

What are the main tasks of oil on modern jet engines?

Answer 1

• lubricating
• cooling
• cleaning
• corrosion protection

Question 2

Where is mineral oil normally used?

Answer 2

Only on piston type engines

Question 3

Where are synthetic oils used?

Answer 3

On jet engines

Question 4

What are the different types of synthetic oils?

Answer 4

• type 1 (used on old engines)
• type 2 (used on modern engines)
• type 3 (used on special aircraft)

Question 5

What are the advantages of synthetic oils?

Answer 5

• Better viscosity
• better thermal stability
• high pressure resistance

Question 6

Can you mix synthetic oils?

Answer 6

No

Question 7

What is the viscosity index?

Answer 7

The effect temperature has on the viscosity of the oil

Question 8

What does a high viscosity index number indicate?

Answer 8

Viscosity least affected by change in temperature

Question 9

What are modern oils measured in and what temperature?

Answer 9

m2/s at 100C

Question 10

What is pour point?

Answer 10

The lowest temperature that oil will move in a 31.75mm test tube horizontally for 5 secs

Question 11

What is fire point?

Answer 11

The lowest temperature that oil will ignite and burn for 5 secs

Question 12

What is meant by volatility?

Answer 12

The measure of the ease in which liquid converts into a vapour

Question 13

What is acidity?

Answer 13

A measure of the corrosive tendencies of the oil

Question 14

What is oil foaming?

Answer 14

The measure of the resistance of the oil to separate from entrapped air

Question 15

What is rubber swelling?

Answer 15

The amount of oil that will cause rubber to swell

Question 16

What is oxidation and thermal stability?

Answer 16

The oil resistance to formation of hard carbon and sludge at high temperature

Question 17

What is corrosiveness?

Answer 17

The effect oil has on metals

Question 18

What is coking?

Answer 18

The amount of carbon residue remaining in the oil after extreme heating

Question 19

What type of fuel is most commonly used in commercial engines?

Answer 19

jet A and jet A1

Question 20

What is jet A and jet A1 manufactured or refined from?

Answer 20

Crude oil petroleum

Question 21

What will fuel normally be made from?

Answer 21

16% hydrogen and 84% carbon with small amounts of impurities

Question 22

What are some of the impurities of fuel?

Answer 22

Sulphur, water, nitrogen

Question 23

What are the characteristics of jet A1 fuel?

Answer 23

• flash point of 38C
• freezing point of -47C
• specific gravity of 0.775-0.83
• most commonly used in Europe
• USA call it JP 1A

Question 24

What are the characteristics for jet A fuel?

Answer 24

• flash point of 38C
• freezing point of -40C
• specific gravity of 0.775-0.83
• most commonly used in America
• USA call it JP1

Question 25

What are the characteristics of jet B fuel?

Answer 25

- flash point -20C - freezing point -58C - specific gravity of 0.751-00.802 - military equivalent is JP4, F40, Avtag

Question 26

What are the characteristics of JP5 fuel?

Answer 26

- flash point of 65C - Freezing point of -48C - preferred by the military because of the high flash point

Question 27

Why must type of fuel used be record after refuelling?

Answer 27

Because each fuel type has different handling and operating traits

Question 28

What is the caloric value of fuel?

Answer 28

18,400 Btujlb

Question 29

What is meant by additives of fuel?

Answer 29

Maximum anti-oxidants and static dissipator

Question 30

What will happen to fuel the higher the altitude?

Answer 30

The ambient pressure decreases which cause fuel to vaporise

Question 31

What is fuel density of jet A and jet A1?

Answer 31

0.81kg/ltr at 15C

Question 32

What is fuel density of jet B?

Answer 32

0.78kg/ltr at 15C

Question 33

What is fuel density of JP5?

Answer 33

0.83kg/ltr at 15C

Question 34

Why are fuel system icing inhibitors used in fuel?

Answer 34

To prevent ice build up in the fuel

Question 35

Why are metal de-activators used in fuel?

Answer 35

They suppress the catalytic effect of some metals

Question 36

Why are biocide additives used in fuel?

Answer 36

To prevent microbiological growth

Question 37

What is fire handling safety divided into?

Answer 37

- fire prevention - fire extinguishing - personal safety

Question 38

What must not take place whilst refuelling or defuelling takes place?

Answer 38

Filling or charging of oxygen bottles

Question 39

Why must you check the shelf life of synthetic oils?

Answer 39

They’re not storage stable

Question 40

Why cant you reuse open synthetic oil?

Answer 40

Because its hygroscopic (collects air moisture)

Question 41

What will long exposure to synthetic oils cause?

Answer 41

Dermatitis

Question 42

What should be done if synthetic oil is ingested?

Answer 42

Do not induce vomiting and drink 250 ml of water

Question 43

How long should you wash your eye for if fuel is in your eye?

Answer 43

10 mins

Question 44

How are fuel leaks caused?

Answer 44

Refuelling malfunctions or by damage to the aircraft

Question 45

When entering a fuel tank your clothes must be made from what?

Answer 45

Cotton

Question 46

When an you enter a fuel tank without a full face mask?

Answer 46

If the tank is considered health safe

Question 47

What is category 1 access to a fuel tank?

Answer 47

You have direct access but cant fit inside

Question 48

What is category 2 access to a fuel tank?

Answer 48

You have direct access and can get inside

Question 49

What is category 3 access to a fuel tank?

Answer 49

No direct external access but can get in

Question 50

What is category 4 access to a fuel tank?

Answer 50

Can only be entered via internal openings which cannot be rescued from

Question 51

How would you get someone out of category 4 tank area?

Answer 51

Mechanical cutters