12 Fuel

Question 1

🟧 LOW PRESSURE
- 1 light in CTR tank
- 2 lights in same Main Tank

Answer 1

• after 10 seconds Master Caution + Fuel will illuminate
• Master Caution + Fuel will illuminate, only 1? illuminations upon recall

Question 2

Main Tank 🟧 LOW
Center Tank 🟧 Config

Answer 2

• illuminates when L or R main tank fuel quantity is less than 907 KG, extinguished when above 1134 KG
• When either engine is running, center tank fuel quantity is greater than 726 KG and both center tank fuel pump switches are OFF
• The amber Fuel Quantity indicators remain amber until: both engines not running, center tank fuel quantity less than 363 KG, one Center tank fuel pump switch ON.

Question 3

🟧 Imbal

Answer 3

displayed when:
- main tanks difference > 453 KG, extinguishes when < 91 KG
- on Ground and in Air
- 🟧 LOW has priority over 🟧 IMBAL
- Shown on main tank with lowest fuel quantity

Question 4

Amount of fuel measuring valves

Answer 4

L and R main tank: each 6
CTR tank 4
total 16

Question 5

Fueling Valves operation

Answer 5

BATT switch turned ON, refueling door open and than the fuel pressure will open the valves.

Question 6

Refueling power control relay

Answer 6

• Refueling door open: fueling system powered and panel lights illuminate
• Refueling door closed: sensor deactivates power to fueling system

Question 7

Fuel indication test switch
- springloaded
- test gages
- fuel door switch bypass

Answer 7

• to OFF position
• check fuel quantity indicators operating
• energizes fuel panel if control relay fails (when door opened)

Question 8

FUELING VALVE POSITION LIGHTS
- extinguished
- illuminating 🟦

Answer 8

• Fuel valve switch is open and tanks are full OR fuel valve switch is closed
• fuel valve switch is open and related tank is not full

Question 9

NGS
- function

• Operational
• Degraded
• Inoperative

-Operates
- Auto shut down

Answer 9

Nitrogen Generation System
- Converts bleed air into Nitrogen-Enriched air during all phases of flight only to Center fuel tank to reduce flammability

-🟩
-🟦
-🟧

• operates after take off until a short period of taxi time
• Auto shut down when:
  A/C on Ground and not on test mode
  Either Engine not running in Flight
  Fire/Smoke detection in Cargo or main deck areas
  Left A/C pack not operating
  Center tank refueling valve open

Question 10

Fuel pumps
- each tank
- powered
- sensors
- highest pressure
- Center Tank low pressure

Answer 10

• 2 in each tank (6 total)
• All AC operated
• each tank has individual pressure sensor.
• Center tank pump highest pressure
• Cause automatic shutdown of Fuel pump (only center tank)

Question 11

Powered
- Fuel crossfeed
- Spar fuel shutoff valve
- Engine fuel shutoff valve

Answer 11

• DC powered by Battery bus
• (located at engine-mounting wing stations), powered by DC from Hot Battery Bus
• Fuel actuated, solenoid controlled valves powered by Battery Bus

Question 12

FWD main tank fuel pump switch

Answer 12

Switched ON: Center tank fuel scavenge jet pump operates automatically to transfer any remaining center tank fuel to main tank No. 1. it starts when No 1 Main tank is 1/2 full and remains until end of flight.

Question 13

Measured Fuel Quantity

Answer 13

Usable Fuel amount.

Question 14

Fuel Temperature Indicator

Answer 14

Sensor located in main tank No 1. Temperature indicating system uses AC power

Question 15

Fuel Tank Capacity

Answer 15

L and R main tank: 3,915 KG
Center tank: 13,066 KG
TOTAL 20,896 KG