12 - Fuel

Question 1

Total Fuel (lbs - no aux)

Answer 1

320.8

Question 2

What is NGS, what does it do, and when does it work/not work?

Answer 2

-Nitrogen Generation System
-converts bleed air to nitrogen-enriched air to reduce flammability of center wing tank fuel
-all phases of flight and for a brief period after landing
-Eng out and Equipment Cooling switch off or Cargo Fire Arm switch ARMED

Question 3

How many pumps are there and how many are required to supply sufficient fuel to operate an engine under all conditions?

Answer 3

-2 in each tank, (center pumps are override/jettison)
-a single pump can supply sufficient fuel under all conditions

Question 4

Is there an auto shutoff for center tank fuel pumps?

Answer 4

Yes, after 15 seconds of continuous low pressure (inhibited during fuel jettison)

Question 5

Do both center fuel pumps operate on the ground?

Answer 5

Only when two electrical power sources are available. With only one power source, PRESS light on non-powered side (EICAS msg inhibited)

Question 6

Where does APU get fuel with no AC power is available?

Answer 6

DC pump in left main