FUEL SYS

Question 1

What type of fuel system do we have?

Answer 1

crashworthy, suction-type system

Question 2

What portion of the main tank is self-sealing?

Answer 2

the lower 1/3

Question 3

What is the capacity of the main tank?

Answer 3

590 gallons or 4,012lbs. of JP-5

Question 4

What is the interconnect level for the left and right tank?

Answer 4

270-600lbs.

Question 5

How is the fuel weighed?

Answer 5

each tank has a fuel probe that is a capacitance-type sensor that employs fuel as a dialectic to measure the fuel weight

Question 6

What creates the required suction to draw fuel from the cells?

Answer 6

the engine driven boost pump

Question 7

Describe the fuel flow.

Answer 7

main tanks – fuel selector levers – engine driven boost pump – pressure sensor – fuel filter – HMU – fuel/oil heat exchanger – ODV – engine for combustion

Question 8

What are the four main functions of the ODV?

Answer 8

1. Provides main fuel flow to the 12 fuel injectors.
2. Purges fuel overboard after shutdown to prevent coking in the injectors.
3. Traps fuel upstream in the fuel/oil heat exchanger so that system priming is not required prior to the next start.
4. Returns fuel back to the HMU if the Np overspeed protection is energized or the EDECU hot start prevention is activated.

Question 9

The external fuel tanks are ______ and _______ hardened.

Answer 9

crashworthy and ballistically

Question 10

What is the capacity of the external fuel tank?

Answer 10

113 or 120 gallons

Question 11

What two sensors does the external fuel tank have?

Answer 11

the low-level thermistor sensor and an overflow thermistor sensor if there is fuel in the external tank vent line

Question 12

What is the rate at which fuel is dumped?

Answer 12

minimum of 800lbs/min.

Question 13

How do you dump fuel from the aux tanks?

Answer 13

TRANSFER and MANUAL OVRD then press L / R INBD and select fuel dump

Question 14

True/False: The fuel dump system is protected by weight on wheels.

Answer 14

FALSE.

Question 15

Single-point pressure refueling has a standard psi of ____.

Answer 15

55psi

Question 16

With power on the aircraft, what order will the tanks fill?

Answer 16

main, right external, left external

Question 17

During gravity refueling, what order are the tanks filled?

Answer 17

any order

Question 18

At what pressure differential will fuel flow stop during HIFR?

Answer 18

20psi

Question 19

What will happen if your left tank vent valve is malfunctioning during HIFR?

Answer 19

uneven filling of the main tank may occur due to trapped air in the left fuel cell causing the fuel level to remain below the high level sensors.

the fuel flow will not be shutoff and the cell will over pressurize and possibly rupture.

If the right cell fills faster than the left, monitor and stop refueling before the right cell is full (1700lbs)

Question 20

When can you initiate an unmonitored manual transfer?

Answer 20

3,200lbs

Question 21

In order to minimize crew desensitization when fuel washes on and off the sensors, the master caution will be displayed when a fuel low condition is detected for a period greater than ________. This condition is deactivated when the condition is not detected for a period of ________.

Answer 21

5 seconds, 20 seconds

Question 22

From which cell is fuel drawn for the APU?

Answer 22

the right cell

Question 23

Describe the difference between [PUMP/VALVE FAIL] and [AUTO FUEL XFER FAULT].

Question 24

When should you check manual fuel transfer operation?

Answer 24

When the main tank has depleted 300lbs

Question 25

When is ALL STORES JETT inhibited for the aux tanks?

Answer 25

<40 gal (272 lbs.)
Use SEL JETT when the aux tank is <300 lbs. because the aux tanks only report in 50 lb. Increments

Question 26

Describe the function of the FMCP mode switch ‘AUTO’

Answer 26

The fuel management logic is not initiated until the main tank <2640lbs.

Question 27

Describe the FMCP mode switch ‘MANUAL OVRD’

Answer 27

Both XFER valves are open, both XFER/dump pumps are on and external fuel is transferred to the main tanks until the high level sensor is reached or the aux tanks are empty.