fuel system

Question 1

describe the fuel system

Answer 1

crashworthy suction type with self sealing tank

Question 2

function of the prime/boost pump

Answer 2

can prime all lines and also acts as a boost pump for APU ops

Question 3

2 reasons we may get a fuel pressure warning

Answer 3

malfunction of eng driven fuel boost pump or air leak in system

Question 4

will we get a fuel press or bypass indication if there is water in the fuel

Answer 4

may not

Question 5

what does putting the fuel pump switch in apu boost do

Answer 5

opens apu fuel shutoff valve and activates prime boost pump

Question 6

what does putting the fuel pump in fuel prime do

Answer 6

opens both eng prime shut off valves

Question 7

main fuel tank capacity

Answer 7

590 usable gallons (4012 lb JP-5)

Question 8

what does the left fuel cell have provisions for

Answer 8

single point refuel/defuel, gravity defuel, HIFR

it also has 2 high level shutoff valves, a check valve, sump drain and vent

Question 9

what does the right fuel cell have

Answer 9

2 check valves, a sump drain, vent, apu fuel line, fuel dump system

Question 10

how much of the tank is self sealing

Answer 10

lower 1/3

Question 11

what is the interconnect level of the two sides of the fuel tank

Answer 11

270-600 lb per side

Question 12

size of the aux tanks

Answer 12

113 or 120 gal

Question 13

purpose of the 2 thermistors in the aux tank

Answer 13

one is an overflow sensor one is a low level (empty) sensor

Question 14

aux tank pump/valve fail vs auto fuel xfer fault

Answer 14

when a single pump/valve fails we get the fail
when both fail we get the fault

Question 15

does auto fuel xfer fault guarantee we can’t use the fuel

Answer 15

no manual mode might work

Question 16

purpose of the 2 transfer dump pumps

Answer 16

either shifts fuel from the aux tanks to the main tank or dumps fuel

Question 17

what fuel do you have to get to in the main tank to do an unmonitored manual fuel xfer

Answer 17

less than 3200 lb

Question 18

after we have burned ___ lb we can do a manual fuel xfer check

Answer 18

300 lb

Question 19

when can we not all stores jett the aux

Answer 19

less than 40 gal or approx 272 lb of fuel but since it reads in 50 lb increments assume anything 300 lb or less will need to sel jett

Question 20

fill sequence with both aux

Answer 20

main, right, left

Question 21

when will auto xfer occur

Answer 21

around 2640 lb

Question 22

auto fuel xfer sequence

Answer 22

left then right

Question 23

if the FMCP is messed up how do you bypass the precheck valves

Answer 23

pull its CB

Question 24

what kind of sensor is used to measure fuel level

Answer 24

capacitance type probe that uses fuel as a dielectric

Question 25

when do the fuel readouts go yellow

Answer 25

when individual tank is below low level sensor (~300lb)

Question 26

what color is good on FMCP BITE

Answer 26

black

Question 27

how long do we have to be low fuel to get an indication and when will it go away

Answer 27

when low fuel situation exists for 5 sec
when it is gone for 20 second

Question 28

minimum fuel dump rate

Answer 28

800lb/min

Question 29

how low will fuel dump dump to

Answer 29

~300 lb per cell

Question 30

how do you dump from the aux tanks

Answer 30

FMCP in transfer man ovrd

Question 31

can you fuel dump with WOW

Answer 31

yes

Question 32

max refueling pressure

Answer 32

55psi

Question 33

HIFR system components

Answer 33

wiggins quick disconnect
pressure refueling fitting
precheck switch
5 element fuse go/nogo canister

Question 34

what pressure differential will stop HIFR fueling

Answer 34

20 psi

Question 35

what is unique about the HIFR go/no go cannister or filter as opposed to other fuel filters

Answer 35

it filters water