15.9 Lubricants and Fuels

Question 1

What are the 4 main tasks of engine lubricant?

Answer 1

Lubricate
Cooling
Cleaning
Corrosion protection

Question 2

What are the 2 types of oil?

Answer 2

Synthetic
Mineral

Question 3

Which type of synthetic oil is used on GTE?

Answer 3

Type 2 (synthetic)

Question 4

Name 3 advantages of synthetic oil

Answer 4

Better viscosity
Better thermal stability
High-pressure resistance

Question 5

What can’t be done with synthetic oils?

Answer 5

Cannot be mixed with other manufacturers, even if the oil is the same type

Question 6

Define viscosity

Answer 6

Ability of a fluid to resist deformation

Question 7

Define pour point

Answer 7

Lowest temperature oil will visibly move in a 31.75mm tube held horizontally for 5 seconds.

Question 8

Define flashpoint

Answer 8

Lowest temperature oil will give off enough vapor to flash when a flame is applied.

Question 9

What is coking?

Answer 9

The amount of carbon residue remaining in the oil after being subjected to extreme temperatures.

Question 10

What is the most commonly used jet fuel in Europe?

Answer 10

Jet A1

Question 11

What is jet A1 flashpoint?

Answer 11

+38 degrees C

Question 12

What is jet A1 freezing point?

Answer 12

-47 degrees C

Question 13

What is the specific gravity for jet A1?

Answer 13

0.775-0.840

Question 14

What are the fuel requirements, in relation to freezing point, flashpoint, and volatility?

Answer 14

• Low freezing point.
• Low flashpoint to allow ignition but high enough for safe handling.
• High volatility for engine starts in all conditions, ground and air.

Question 15

What method is used to detect water that has dissolved in fuel?

Answer 15

Syringe test cartridge.

Question 16

What are the two main additives used in aviation fuel?

Answer 16

• Anti-ice additive.
• Anti-microbial additive.

Question 17

What does anti-ice additive prevent the formation of ice

Answer 17

Reduces the fuel’s freezing point.

Question 18

What type of jet fuel is used for extreme cold climates?

Answer 18

Jet B (freezing point of -58 degrees C).

Question 19

What are the five factors which affect oil performance?

Answer 19

• Oil foaming.
• Rubber swelling.
• Corrosiveness.
• Pressure.
• Coking.

Question 20

How easy a liquid converts to a vapor is known as what?

Answer 20

Volatility.

Question 21

What is the result of a higher viscosity index?

Answer 21

Viscosity is less affected by temperature.

Question 22

What is the Pour point of type 2 synthetic oil?

Answer 22

-57 degrees C

Question 23

Type 2 viscosity must be higher than ___ at 90°C and lower than ___ At -40°C.

Answer 23

5cs
13000cs

Question 24

What happens to the oil viscosity as temperature increases?

Answer 24

Viscosity decreases.

Question 25

What is meant by the pressure resistance of oil?

Answer 25

Ability for the oil to keep its lubricating film between components, when under loads.

Question 26

What are static dissipator additives used for?

Answer 26

To reduce hazardous effects of static electricity generated by the high fuel flow rate through the system.

Question 27

What are etal deactivators, in relation to fuel additives?

Answer 27

They suppress the catalytic effect that metals have on fuel oxidation.

Question 28

What should you do if you ingest oil or fuel?

Answer 28

• Do NOT induce vomiting.
• Drink 250ml of water.
• Seek medical attention.

Question 29

What should be done if your skin comes into contact with fuel?

Answer 29

Wash thoroughly with soap and water, as it can cause dermatitis.

Question 30

What is thermal ability?

Answer 30

The ability to resist decomposition at high temperatures.

Question 31

What is viscosity measured in?

Answer 31

Centistrokes (cs)