Fuel

Question 1

Explain the meaning of an illuminated main tank fuel pump LOW PRESSURE light

Answer 1

Fuel pump output pressure is low, or FUEL PUMP switch is off

Question 2

Two LOW PRESSURE lights illuminated in the same tank illuminate …

Answer 2

MASTER CAUTION and FUEL system annunciator lights

Question 3

One LOW PRESSURE light causes …

Answer 3

MASTER CAUTION and FUEL system annunciator lights to illuminate on MASTER CAUTION RECALL

Question 4

Describe the logic of the blue crossfeed VALVE OPEN light

Answer 4

Bright:
- valve in transit
OR
- valve position and CROSSFEED selector disagree

Dim:
- valve is open

Extinguished:
- valve is closed

Question 5

Describe the logic of the blue ENGINE VALVE CLOSED and SPAR VALVE CLOSED lights

Answer 5

Bright:
- valve in transit
OR
- valve position and engine start lever or engine fire switch in disagreement

Dim:
- valve is closed

Extinguished:
- valve is open

Question 6

Describe the meaning of an illuminated fuel FILTER BYPASS light

Answer 6

Impending fuel filter bypass due to a contaminated filter

Question 7

Describe the meaning of a fuel quantity LOW alert

Answer 7

Displayed (amber):
- fuel qty less than 2000 lbs in related main tank

Note: fuel qty digits on tank(s) with low qty turn amber

Question 8

Describe the meaning of a fuel CONFIG alert

Answer 8

Displayed (amber):
- either engine running
- center fuel tank qty greater than 1600 lbs and both center fuel tank pumps produce low or no pressure

Note: the qty digits on the center tank fuel qty indicator turn amber

Question 9

Describe the meaning of a fuel IMBAL alert

Answer 9

Displayed (amber):
- main tanks differ by more than 1000 lbs
- displayed below main tank with lower fuel qty
- displayed when airplane is on ground or in air
- inhibited by fuel LOW indication when both conditions exist
- displayed until imbalance is reduced to 200 lbs

Note. The fuel qty digits on tank with lower fuel qty turn amber

Question 10

Describe two ways to close the spar and engine fuel shutoff valves

Answer 10

• Place the engine start lever to CUTOFF
• Pull the engine fire warning switch

Question 11

Explain how fuel is supplied to the engines with all pumps operating

Answer 11

Center tank pumps produce higher pressure than main tank pumps. This ensures that center tank fuel is used before main tank fuel.

Note: when the main tank fuel pump pressure is low, each engine can draw fuel from it’s corresponding main tank through a suction feed line that bypasses the pumps