Fuel

Question 1

How is fueling and defueling accomplished?

Answer 1

At the single-point pressure fueling station in the right wing.
Don’t need power on airplane to fuel (hot battery bus item)

Question 2

What is the purpose of the surge tanks?

Answer 2

Designed to collect overflow.
Capacity 235 lbs. Overflow drains back to main tanks. High surges may cause fuel to
drain through the main fuel vent at the wing tip (think you were fueled to max at night in Vegas then the fuel expands and spills when its hot, just an ex)

Question 3

What is the purpose of the Fuel Crossfeed valve?

Answer 3

Any tank to any engine

Question 4

With all pumps operating, which tank fuel is burned first?

Answer 4

Center fuel is burnt first (these pumps have a higher output pressure)
Then respective main tank fuel is burnt

Question 5

What ensures this tank fuel is used before other tanks?

Answer 5

The Center Tank Pumps have a higher output pressure.

Question 6

Can the APU suction feed fuel? From which tank?

Answer 6

Yes, from Main Tank No. 1

Question 7

What causes the Center Tank Fuel Scavenge Jet Pump to activate?

Answer 7

A float valve when fuel in Main Tank 1 drops below 4500lbs.

Question 8

What is the light logic of the Crossfeed VALVE OPEN light?

Answer 8

VALVE OPEN (bright blue) = in transit or disagree
VALVE OPEN (dim blue) = valve is open with selector open
Light goes out when the selector and switch are both closed.

Question 9

What causes an IMBAL (amber) alert, and where do you see it?

Answer 9

IMBAL = more than 1000lb imbalance between tanks 1 & 2 for more than 60 sec

Will appear under the digital fuel readout on the low side.

Question 10

What causes a CONFIG (amber) alert, and where do you see it?

Answer 10

CONFIG = When either Eng is running, Center pumps are off and more than
1600lbs in Center Tank. UPPER DU.

Will appear under digital readout for center tank.

Question 11

What causes a fuel LOW (amber) alert, and where is it indicated?

Answer 11

FUEL LOW = less than 2,000lbs in respective tanks for greater than 30 seconds.

Question 12

Where is the Nitrogen Generation System indicator?

Answer 12

Main Wheel well adjacent to the APU Fire Control Panel.

Question 13

With the loss of AC powered fuel pumps, how is fuel provided to the engine?

Answer 13

A suction feed line to main tanks that bypasses the pumps.

No center tank fuel with loss of AC power

Question 14

What is the logic of the center tank fuel pumps?

Answer 14

10 sec after continuous LOW PRESSURE indicated - FUEL annunciator/
MASTER CAUTION

Additional 5 seconds (15 seconds total) after continuous LOW PRESSURE indicated - Pump Shuts OFF.

When the switch is moved to off the shutoff logic resets.

If center tank is below 1000 lbs then fuel pump switches must be off for takeoff.

Question 15

If a fuel quantity indicator fails, how is actual fuel quantity determined?

Answer 15

Fuel measuring sticks

dip sticks under wing

Question 16

What does the Engine Start Lever control? What occurs in each position?

Answer 16

They control the Spar Fuel Shutoff Valve and the Engine Fuel Shutoff Valve.

In IDLE:
- Ignition system energized via EEC
- spar valve is opened 
- engine fuel Shutoff Valve is opened. 
In CUTOFF:
- Spar valve and engine fuel Shutoff valves close
-ignition system de energizes. 

SH 7.01 p 6

Question 17

What do the ENG VALVE CLOSED and SPAR VALVE CLOSED lights indicate? What is their
light logic?

Answer 17

Light logic :
CUTOFF - Off- ENG VALVE & SPAR VALVE closed
(engine high pressure fuel shut off valve is open
** Wont illuminate once engine is started)

MOVE TO IDLE - BRIGHT Blue - ENG VALVE & SPAR VALVE in transit or disagrees with lever position

IDLE - LIGHT EXTINGUISHED - DIM Blue - ENG VALVE & SPAR VALVE (closed)