Fuel System

Question 1

When does automatic fuel transfer happen from the center tank to the wings?

Answer 1

When the left or right wing tank quantity falls below 93%. The transfer ejectors in the center tank are activated until the main wing tank quantities reaches 97%

Question 2

Flight Control Fuel Panel -

What happens when left or right boost pump is pressed in?

Answer 2

White On Light Illuminated - the pump is operating
Amber INOP light illuminated - pump output pressure low
No lights illuminated - pump is armed and standby

Question 3

Flight Control Fuel Panel -

Left or right boost pump pressed out?

Answer 3

Disarms the respective pump and illuminates the inop light

Question 4

Flight Control Fuel Panel -

GRAVITY XFLOW switchlight? (pressed in)

Answer 4

The gravity crossflow shutoff valve (SOV) opens and the open light illuminates

Question 5

Flight Control Fuel Panel -

GRAVITY XFLOW switchlight? (pressed out)

Answer 5

The SOV closes and the open light extinguishes

Question 6

Flight Control Fuel Panel -

GRAVITY XFLOW switchlight? What does the fail light indicate?

Answer 6

The SOV is not in the commanded position

Question 7

Flight Control Fuel Panel -

XFLOW AUTO OVERRIDE switchlight?

Answer 7

Pressing arms the bidirectional pump for manual operation through the use of the left or right crossflow switch light and overrides automatic pump operation.

Question 8

Flight Control Fuel Panel -

L or R CROSSFLOW switchlight? (Pressed in)

Answer 8

The bidirectional crossflow pump is activated and fuel is pumped into the selected side. The on light will illuminate.

Question 9

Flight Control Fuel Panel -

L or R CROSSFLOW switchlight, what does the fail light indicate?

Answer 9

The pump failed to activate when commanded either manually or automatically

Question 10

Describe the fuel tank venting system

Answer 10

There NACA vents and climb vents. The tanks are positively pressurized.

Question 11

Where is the bulk fuel temperature sensor?

Answer 11

In the right wing

Question 12

Fuel quantity gauging control (FQGC) -

Explain the automatic fuel cross flow system

Answer 12

The FQGC detects a fuel imbalance of 200 lbs between the wings the crossflow pump will activate and will continue to operate until the low wing has 50 lbs more fuel than the wing with the previous higher quantity.

Question 13

How is fuel manually transferred?

Answer 13

First press the MAN XFLOW AUTO OVERRIDE switchlight. Then press the left or right crossflow switchlight on the low side.

Question 14

Will the main engines start without their respective boost pump running?

Answer 14

Yes

Question 15

At what fuel quantity does the digital fuel readout turn amber?

Answer 15

Less than 1200 lbs total or less than 600 lbs per wing

Question 16

What is the maximum fuel imbalance while over-wing refueling?

Answer 16

2500

Question 17

Describe the path of fuel from the center tank to the engines

Answer 17

TSM
Transfer ejector from the center tank to the main tank
Scavenge ejector from the main tank to the collector tank
Main ejector from the collector tank to the engines

Question 18

How does fuel enter the collector tanks?

Answer 18

One way flapper valves allows fuel to move by gravity into the collector tank

Scavenger ejectors