Fuel

Question 1

What is the Maximum Useable Fuel load during pressure refuelling?

Answer 1

• Wings: 17,550 lb + 17,550 lb.
• Center: 14,200 lb.
• Aft Tank: 2,550 lb.
• TOTAL: 51,850 lb.

Question 2

Which tanks cannot be gravity refueled?

Answer 2

• Center & Aft Tank.

Question 3

What are the limitations using Wide-cut fuels?

Answer 3

Wide-cut fuels Prohibited.

Question 4

Which Tank normally provides fuel for the APU?

Answer 4

Right Wing Tank Collector.

Question 5

What powers the Refuel/Defuel Panel?

Answer 5

MAIN BATT Bus (refuel possible without external or airplane-generated power).

Question 6

What is the Maximum permissible Fuel Imbalance?

Answer 6

• Ground Ops and T.O./Ldg: 600 lb.
• Fuel Imbalance In-Flight: 1,100 lb.

Question 7

What is the Fuel Imbalance Quantity Level to activate the wing-to-wing Auto-Transfer System?

Answer 7

• Ground: 340 lb;
• Flight: 510 lb.
  Note: Longitudinal CG Control is temporarily suspended during Auto-Transfer activation.
  Lateral fuel transfer is stopped when the imbalance decreases below approximately 180 lb.

Question 8

The Longitudinal CG transfer happens between which tanks?

Answer 8

• Between the Collector Tanks and the Outer Tanks.
  Note: it becomes disabled when Inner Tanks are below 10,850lbs).

Question 9

When will the FQMC command the FRTT (Fuel Return to Tank) valve open?

Answer 9

The FRTT will automatically operate:
- Above FL 300, and
- Wing Fuel Temperature Below - 20°C.
- Automatically closes if any fuel tank Temp sensor is -5°C or higher, or when the Alt is below 30,000 ft.
Note: To prevent wing tank fuel from freezing or gelling, the fuel recirculation system heats the fuel in the wing inner
tank by automatically transferring hot fuel from the engine fuel/oil heat exchanger into the inner tanks with FRTT SOV.
When the CG control system is operating, the heated wing inner tank fuel is pumped into the wing outer tanks.
The Fuel recirculation system will not operate if the fuel Xfeed valve is opened and both engines are receiving fuel from
a single collector tank.

Question 10

What is the Minimum Fuel Quantity for Manual Wing-to-Wing Fuel Transfer?

Answer 10

2,500 lb per Wing Tank.

Question 11

Why must the crew monitor Manual operation of the Wing-to-Wing Transfer System?

Answer 11

Because there’s no automatic shutdown of the manual system nor overfill protection provided to stop
operation, and it could create another imbalance to the other side.

Question 12

When must the Fuel Crossfeed be OFF according to System Logic?

Answer 12

• It must be Off for Takeoff and Landings (AEO & OEI);
• For Dual Engine operations, it must be selected OFF below 10,000 ft.

Question 13

How is positive Fuel Tank Pressure maintained during flight?

Answer 13

Ram air via the NACA scoops on the bottom of each surge tank located at the wing tips.

Question 14

To avoid Fuel Spillage, at what fuel quantity should the PRV handles NOT be pulled?

Answer 14

• Wing Tank Quantity more than 11,300 lb;
• Center Tank Quantity more than 12,000 lb.

Question 15

During the refuel SOV test, the SOV FAIL message in the PRESEL window on the refuel panel indicates:

Answer 15

Fuel Flow will NOT stop when the tank is full.

Question 16

When do the primary AC Fuel Pumps operate in flight?

Answer 16

• ENGINE RUN switches to ON;
• XFEED SOV is open.

Question 17

When do the Auxiliary DC Fuel Pumps automatically operate?

Answer 17

• APU Ground Start with no AC power;
• When low pressure is sensed at the AC Fuel Pump outlet
  (may be caused by an AC Pump failure, loss of power to the Primary Pump or Deselection of the Primary Pump).

Question 18

What does the Amber FUEL QTY MISCOMPARE CAS message indicate?

Answer 18

Miscompare between the FMS Calculated Fuel and the Sensed Fuel onboard.

Question 19

Where does the FUEL QTY MISCOMPARE message appear?

Answer 19

EICAS

Question 20

Where is the Fuel SOV located and How is the Valve closed?

Answer 20

• The Fuel SOV is located in the Engine Feedline at the Firewall.
• It’s Closed by pressing the associated Engine FIRE PBA.

Question 21

When does the Fuel Transfer from the Center Tank to the Wing Inner Tanks begin?

Answer 21

• When the Inner Tank quantities decrease to about 14,000 lb;
• Continues until Wing Inner Tanks reach full capacity (approximately 15,000 lb).

Question 22

When will the Wing Outer Tanks deplete into the Wing Inner Tanks?

Answer 22

• When the Wing Inner Tanks decrease to about 10,850 lb.
  Note: That’s why the Longitudinal CG is disabled when the Inner Tanks go below 10,850 lbs.

Question 23

When does the Fuel Transfer from the Aft Tank to the Wing Inner Tanks begin?

Answer 23

When either Wing Inner Tank quantity decreases to below 6,800 lb.

Question 24

When is the Longitudinal CG Control inhibited?

Answer 24

• By pressing the CG CTRL PBA;
• When Wing-to-Wing transfer is automatically or manually initiated;
• When the fuel quantity of each Wing Inner Tank reaches 10,850 lb or below.