15.9 LUBRICANTS AND FUELS👌🏼

Question 1

Function of engine oil

Answer 1

• lubricating
• cooling
• cleaning
• corrosion protection

Question 2

What are the 2 types of engine oils

Answer 2

• synthetic
• minerals

Question 3

What are the 3 different type of synthetic oils

Answer 3

• type 1 (used on old gas turbines)
• type 2 (modern gas turbines)
• type 3 (higher thermal stability and viscosity at high temp than type 2) (used on special aircraft)

Question 4

Advantages of synthetic oils

Answer 4

• better viscosity
• better thermal stability
• high pressure resistance

Question 5

Drawback of synthetic oils

Answer 5

• expensive

Question 6

Explain viscosity index

Answer 6

• higher number = viscosity least affected by temp change

Question 7

Explain viscosity

Answer 7

• internal resistance of a fluid against deformation

Question 8

If viscosity is high what does that mean

Answer 8

Fluid is thick (viscous)

Question 9

Explain pour point

Answer 9

Lowest temp oil will visibly move

Question 10

What is the pour point for type 2 oils

Answer 10

-57*c

Question 11

Explain flash point

Answer 11

• lowest temp that oil will give enough vapour to flash when flame is applied

Question 12

What is the flash point for type 2 oils

Answer 12

> 250*c

Question 13

Explain oxidation resistance

Answer 13

• resists reaction between oil and oxygen
• when oil reacts with oxygen, it gets thicker (increases viscosity)

Question 14

Explain volatility

Answer 14

• liquid converted into a vaporous state

Question 15

Explain acidity

Answer 15

• measure of corrosive tendencies of the oil

Question 16

Explain oil foaming

Answer 16

• resistance of oil to separate from entrapped air

Question 17

Explain rubber swelling

Answer 17

Amount of oil that will cause a particular rubber compound to swell

Question 18

Explain corrosiveness

Answer 18

• effect the oil has on various metals
• especially copper

Question 19

Explain coking

Answer 19

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

Question 20

Explain jet A1 (DERD 2494)

Answer 20

• common fuel type for jet engines in Europe
• American name ‘JP 1A

Question 21

Explain Jet A

Answer 21

• common fuel type for jet engines in America
• JP 1

Question 22

Explain Jet B (DERD 2486)

Answer 22

• flash point -20c (-4F)
• used in Canada (cold weather)

Question 23

Explain JP 5

Answer 23

• type of military fuel
• high flash point (65*c)
• low freezing point (-48*c)

Question 24

Water encourages ice build up if fuel cools below what temperature

Answer 24

0*c

Question 25

Explain anti ice additives

Answer 25

- can be added to bulk fuel or aircraft fuel tank

Question 26

What anti ice solution is in the additive

Answer 26

Diethylene glycol solutions that work as a antifreeze agent

Question 27

Explain anti-oxidants

Answer 27

Prevent formation of gum deposits on fuel system components

Question 28

Explain static dissipated additives

Answer 28

- reduce hazardous effects of static electricity generated by fuel movement

Question 29

What can prolonged or repeated contact of engine oil with the skin cause

Answer 29

Irritation and dermatitis

Question 30

If engine oil contacts the skin, what should be done

Answer 30

- wash thoroughly with soap and warm water

Question 31

Do synthetic oils have a shelf life

Answer 31

Yes

Question 32

Are synthetic oils storage stable and why

Answer 32

No because synthetic oil is hygroscopic