Fuel Systems

Question 1

What is AVGAS

Answer 1

Aviation gasoline - used for piston engine aircraft

Question 2

What is AVTUR

Answer 2

Aviation Turbine - Used for gas turbine powered aircraft

Question 3

What is calorific value

Answer 3

The amount of heat released when a unit mass of fuel is burned

Question 4

What is volatility

Answer 4

Tendency of a substance to evaporate at normal temperatures

Question 5

What is specific gravity

Answer 5

The weight/density of a liquid compared to water

Question 6

What are the 4 approved aviation fuels

Answer 6

AVTUR (kerosene)
AVTAG (kerosene and gasoline)
AVCAT (Similar to AVTUR but has a higher flash point)
AVGAS (gasoline)

Question 7

What is FSII

Answer 7

Fuel system ice inhibitor

Question 8

What colour code represents AVTUR

Answer 8

White on black

Question 9

What colour code represents AVCAT

Answer 9

Yellow on black

Question 10

What colour code represents AVTAG

Answer 10

Green on black

Question 11

What 2 aircraft systems contain fuel

Answer 11

Airframe fuel system
Engine fuel system

Question 12

What are the design objectives of a fuel system

Answer 12

Rapid fuel replenishing
Flexibility of operation (range and endurance)
Tolerance to manoeuvre and damage
Secondary uses of fuel (coolant)
Automatic or semi automatic control of system

Question 13

What are the 3 types of fuel tank

Answer 13

Rigid
Integral (built in)
Flexible

Question 14

What is the purpose of a collector tank

Answer 14

Fuel is fed through them from various systems, and they provide an uninterrupted flow of fuel into the engine

Question 15

What is the purpose of tank pressurisation

Answer 15

Maintain the pressure of air above the fuel at an appropriate level

Question 16

What is the effect of altitude on the fuel system

Answer 16

Boiling point decreases (risk of fire)

Question 17

What is the purpose of unpressurised tanks

Answer 17

Open to atmospheric pressure to allow inward venting of air when fuel level is lowering and outward venting of air when fuel level is rising

Question 18

What is an Air/No fuel valve

Answer 18

A valve fitted to the top of a tank that allows air in, but no fuel out during inverted flight of climbing

Question 19

What are the advantages of pressurised tanks

Answer 19

Air pressure can be used to transfer air
Prevents excessive fuel vapour
Reduces fire risk
Maintains tank shape

Question 20

What is the purpose of the LP cock

Answer 20

To separate the airframe fuel system from the engine fuel system
Allow full flow or none at all to the engine
Can be used in emergencies to shut down engine

Question 21

Where is a booster pump positioned

Answer 21

In a sump to ensure supply no matter the attitude of the aircraft

Question 22

What is an FCOC

Answer 22

Fuel cooled oil cooler

Cools hot oil as it flows around pipes containing colder fuel
Also prevents ice from forming in fuel lines

Question 23

What is an ACFC

Answer 23

Air Cooled Fuel Cooler

Fuel is cooled before returning to the tanks and prevents damage to pipelines, sealants and stops vapour forming in the pipelines

Question 24

How does an ejector work (fuel pump)

Answer 24

Mixes hot oil with cold fuel using pressure to draw both together

Question 25

What are the 4 methods of transfer

Answer 25

Air pressure Electric transfer Fuel ejector Gravity

Question 26

What 2 components are used to monitor fuel tank level and control

Answer 26

Float valve Float switch

Question 27

How do self sealing coverings work

Answer 27

The rubber between the outer and inner layer of the tank swells on contact with fuel and closes the hole

Question 28

What are the 2 types of fuel contents transmitter

Answer 28

Float type Gauging unit

Question 29

How is fuel quantity measured

Answer 29

Kilograms or pounds

Question 30

What 3 indications can be given by the fuel gauging system

Answer 30

Total system contents Contents of individual tanks Amount of fuel being used at any time

Question 31

What is the purpose of the fuel flow transmitter

Answer 31

Sense the volume of flow of fuel being consumed by the engine and transmit an electrical signal

Question 32

What are the 3 manual methods of measuring the fuel level

Answer 32

Dipstick Drip stick Drop stick

Question 33

What are the 5 threats to fuel

Answer 33

Foreign particles Water Microbiological organisms Cross contamination User responsibilities

Question 34

What tests care carried out after disturbing the fuel system and the fitting of any component

Answer 34

Leak check Fuel flow test

Question 35

How is water collected for a sediment check

Answer 35

Drained from a valve in the bottom of a container, into a transparent container

Question 36

How is health risk reduced during tank maintenance

Answer 36

Preparation draining Venting Inspection lamps PPE 2nd person

Question 37

What are the 2 methods of refuelling on the ground

Answer 37

Open line refuelling Pressure refuelling

Question 38

What are the 3 types of defuelling

Answer 38

Pressure defuel Open line Drain

Question 39

What are the 4 types of PPE that should be worn during fuelling

Answer 39

Safety boots Coveralls Gloves Goggles

Question 40

What type of booster pump is used in a fuel supply system and why

Answer 40

Impeller pump It can rotate constantly with zero flow, still allowing fuel to reach the engine

Question 41

What 6 rules must be followed when refuelling in a hangar

Answer 41

Authorised Adequate ventilation High volume fire fighting vehicle in attendance Suitable towing vehicles Fuel bowser outside Obstruction free escape route

Question 42

What are the 5 bonding procedures during fuelling

Answer 42

Aircraft and bowser are earthed Connect aircraft and bowser by bonding lead Connect hose to bonding point Connect fuelling hose and refuel Disconnect bonding in reverse order