Chapter 5 - Fuel System

Question 1

What is the purpose of the fuel system?

Answer 1

To provide a positive flow of fuel to the 3 power plants and APU during all stages and conditions of flight

Question 2

How many fuel tanks are there? - and name them

Answer 2

4 tanks
1, 2 & 3 - Main Tanks
4 - Transfer Tank

Question 3

What bays are each tank located in?

Answer 3

Tank 1 - Bay 6
Tank 2 - Bay 3
Tank 3 - Bay 2
Tank 4 - Bay 1

Question 4

What is the purpose of the fuel tank?

Answer 4

To hold fuel and provide a mounting for the fuel delivery, transfer and gauging components

Question 5

What does Tank 4 provide?

Answer 5

Provides a back up fuel supply to No.1, 2 & 3 fuel tanks

Question 6

How are the fuel tanks separated from the fuselage?

Answer 6

By a secondary structure, capable of absorbing local impact damage conditions

Question 7

What is each tanks capacity?

Answer 7

Approximately 820kg pressure refuel

795kg gravity refuel

Question 8

What other methods can be used to refuel?

Answer 8

Ferry Tank
HIFR
Air to Air

Question 9

What is a Ferry Tank?

Answer 9

A large tank fitted to a pallet fastened to the cabin floor and is connected to the aircraft fuel system by a fuel feed pipe

Question 10

What is used to ensure a positive fuel flow to the booster pumps?

Answer 10

A collector tank

Question 11

What is on the canister assembly/ collector tank to ensure a positive supply of fuel? (2)

Answer 11

Flap Valves

Jet Pump

Question 12

How does a jet pump operate?

Answer 12

Uses the booster pump to initiate the suction of fuel from the fuel tank to the collector tank via a venturi effect

Question 13

What fuel tank supplies fuel to the APU?

Answer 13

No. 2 Fuel Tank

Question 14

What is the purpose of the fuel delivery filtration system?

Answer 14

To maintain fuel cleanliness prior to entering the powerplant/ APU

Question 15

What is the Merlin Fuel system dependent on?

Answer 15

Dependent solely on the anti-icing additives in the fuel as there is no anti-icing facility

Question 16

How many booster pumps are there and where are they located?

Answer 16

6

2 each in Tanks 1, 2 & 3

Question 17

How are the 2 booster pumps connected?

Answer 17

Via a manifold to provide a single positive feed to their respective engines

Question 18

What does the booster pump manifold have incase of a double pump failure?

Answer 18

A suction pipe

Question 19

What is at the base of the booster pump?

Answer 19

A strainer/ filter

Question 20

Where is the distribution manifold located?

Answer 20

On the transmission deck, fwd of the No.1 EECU

Question 21

What is the purpose of the distribution manifold?

Answer 21

Allows any engine to be cross fed with fuel from any main tank
Allows fuel supply to be shut off at the manifold

Question 22

What type of pump is the APU pump?

Answer 22

Electrical pump

Question 23

What are the 2 modes of operation for the transfer pumps?

Answer 23

Automatic and Manual

Question 24

What type of valves are Transfer and Dump Valves?

Answer 24

Dual purpose valves

Question 25

What do Transfer and Dump valves allow?

Answer 25

Allow fuel into the main takes

Allow fuel from the tanks to the gallery

Question 26

At what point does tank 4 automatically transfer fuel into other tanks?

Answer 26

When the tank reaches 70% on the level float switch

Question 27

Which tank does not have an external vent pipe on the left side?

Answer 27

Tank 4

Question 28

What are the components of the vent system?

Answer 28

Cross-over vent pipes
Air.no fuel valves
Expansion Tanks
Spill Sensors
Anti-siphon valves
Vent pipes with flame traps

Question 29

What does the air/no fuel valve do?

Answer 29

Prevents fuel from entering the external pipelines

Allows residual fuel to drain from the vent pipes

Question 30

What do expansion tanks do?

Answer 30

help correct fuel overspill problems during refuel operations
Contain baffles to prevent fuel surge through the vent system

Question 31

What are Anti-siphon valves?

Answer 31

Act as non return valves due to differential pressure if the vent pipes fill with fuel
Creates a suction effect when the valve opens to stop fuel flow

Question 32

Where are the external vent pipe exits located?

Answer 32

Sides of the cabin

Question 33

How is the fuel system controlled?

Answer 33

Electronically from the cockpit

Question 34

What is the FIEU and what does it do?

Answer 34

Fuel Indicating Electronic Unit

Monitors the signal from the probes and displays the information on the IDU

Question 35

How many fuel gauging probes does each fuel tank have?

Answer 35

3

2 primary, 1 secondary

Question 36

Where is the APU pump located?

Answer 36

port side, below the fuel manifold