Fuel

Question 1

When does the standby fuel pump operate:

Answer 1

If the switch is in AUTO whenever engine inlet fuel pressure falls below 7 psi, or
when jettisoning fuel, or
whenever the switch is in the ON position

Question 2

Explain how fuel transfer works:

Answer 2

Transfer valves between the central tank upper and the wings open to allow fuel from below the standpipe in the central tank upper to gravity feed into each wing.
The pilot actuates the OPEN position on the Fuel Transfer switch during any type of refueling.
Fuel Transfer will occur automatically in the AUTO position when the central tank lower depletes.

Question 3

Explain how fuel interconnect works:

Answer 3

Forward and aft interconnect valves open to laterally balance the wings when the pilot positions the INTERCONNECT switch to the OPEN position. Balancing is accomplished by gravity.

Question 4

List the order of tank depletion of the fuel system:

Answer 4

Central tank upper above the stand pipe
Central tank lower
Central tank upper below the stand pipe
Wing tanks (both evenly)
Collector Boxes

Question 5

What are the Collector Box fuel capacities:

Answer 5

Left engine is 32.5 lbs

Right engine is 29.5 lbs because it contain the aft interconnect valve which takes up room inside the box

Question 6

How can the max fuel be loaded, by gravity or pressure fueling:

How much more fuel could be uplifted:

Answer 6

Pressure

13.2 gallons

Question 7

Can you JETTISON fuel on the ground:

Can you JETTISON fuel without an operating STBY pump:

Can you JETTISON fuel with the respective STBY pump switch selected OFF

What is the rate at which fuel jettison is accomplished:

When would fuel jettison be automatically terminated:

Answer 7

YES
NO
YES - Fuel JETTISON pushbutton will turn it ON regardless
100 lbs/min/side - 200 total
By a float switch at 600 lbs remaining in the respective tank

Question 8

When would you get a FUEL TEMP HI annunciator:

Answer 8

When the fuel temperature downstream of the fuel/oil heat exchanger reaches 275 deg F

Question 9

How many ejector (jet) pumps are there:

Answer 9

8, 2 Primary (hi pressure) and 6 Transfer ejectors (2 in each wing and 2 in the central lower tank)

Question 10

When will the FUEL LVL LO annunciator illuminate:

Answer 10

450 lbs fuel remaining in either tank or either collector box not full