Fuel System

Question 1

How many fuel cells are there?

Answer 1

5

Question 2

How are the fuel cells organized?

Answer 2

RALF
Right - Aft and center
Left - Forward and dorsal

Question 3

How many pounds of fuel can be held?

Answer 3

4084 total
3906 single point refueling
3866 over the wing

Question 4

When does the fuel low light come on?

Answer 4

less than 250lbs for 7.5 sec

Question 5

What is the solo restriction for fuel?

Answer 5

right must not be more than 2x the left as this creates CG issues

Question 6

What do the boost pumps do?

Answer 6

Send low pressure fuel to the engine driven pumps

Question 7

What is normal fuel px?

Answer 7

10 PSI

Question 8

When does fuel px light come on?

Answer 8

6 PSI

Question 9

When is fuel gravity flow sufficient?

Answer 9

below 25k in MAX
flameouts have happened at 7k
below 6k gravity flow is guaranteed

Question 10

What are the fuel shutoff switches powered by?

Answer 10

Left DC

Question 11

What are the numbers associated with fuel imbalances?

Answer 11

0-50: no display
60-190: white display
200+: red, Xfeed

Question 12

What is the problem with fuel pressure light and crossfeed off?

Answer 12

Boost pump failure

Question 13

What is the problem with fuel pressure light and crossfeed on?

Answer 13

Fuel leak

Question 14

What powers crossfeeding?

Answer 14

Left DC, switch opens and closes valve in crossfeed fuel manifold

Question 15

What can cause a rapid fuel imbalance?

Answer 15

crossfeed on and either both boost pumps on or off

Question 16

What happens if crossfeed is left on until the tank is dry?

Answer 16

A dual flameout occurs

Question 17

When is crossfeeding not recommended?

Answer 17

BILLL
Boost pump inop
Indicator failure
low altitude
low fuel
leak

Question 18

When is there an exception to crossfeed?

Answer 18

Single engine with <250 pounds

Question 19

Does fuel flow show AB values?

Answer 19

No, the fuel flow sensor is only on the main fuel flow line

Question 20

What powers the fuel quantity indicators?

Answer 20

Right AC

Question 21

How many fuel probes are there?

Answer 21

7

Question 22

What does the red bar mean for fuel qty?

Answer 22

less than 250 for 7.5 sec

Question 23

What should you do if you have a fuel low caution light?

Answer 23

Maintain positive pitch to prevent cavitation from uncovered boost pump inlets

Question 24

How much is boost pump output reduced with 650lb in the system?

Answer 24

40%

Question 25

Can you use MAX with less than 650lb?

Answer 25

No

Question 26

When should you not taxi?

Answer 26

With less than 150lb each side

Question 27

When should you avoid MAX?

Answer 27

in 0 or negative G flight exceeding 10 sec at 10K and 30 sec at 30K

Question 28

What is the FF of AB?

Answer 28

7300 PPH at SL 11400 at Mach 1 SL

Question 29

How many spray bars are on the AB?

Answer 29

16 spray bars 4 pilot spray bars

Question 30

How is fuel flow metered?

Answer 30

throttle position and compressor discharge pressure

Question 31

What is T2 cutback?

Answer 31

auto reduction in RPM and EGT to prevent over-pressurization and high corrected speed limits of compressor at low compressor inlet temps, when high altitude, low airspeed

Question 32

What is T2 bias?

Answer 32

the sensor can read much higher than actual compressor inlet temp and increases stall susceptibility due to the misguided T2 read by main fuel control and T5 scheduling