Fuel

Question 0

Describe the logic of the blue crossfeed VALVE OPEN light.

Bright
Dim
Extinguished

Answer 0

Bright:

• Valve in transit, or
• Valve position and CROSSFEED Selector disagree.

Dim:
-Valve is open.

Extinguished:
- Valve is closed.

Question 1

Explain the meaning of an illuminated Main Tank Fuel Pump LOW PRESSURE light.

(2)

Answer 1

Fuel pump output pressure is low, or FUEL PUMP switch is OFF.

Note: Two LOW PRESSURE lights illuminated in the same tank illuminate MASTER CAUTION and FUEL system annunciator lights. One LOW PRESSURE light causes MASTER CAUTION and FUEL system annunciator lights to illuminate on MASTER CAUTION light recall.

Question 2

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

Bright
Dim
Extinguished

Answer 2

Bright:

• Valve in transit, or
• Valve position and engine start lever or engine fire warning switch in disagreement.

Dim:
-Valve is closed.

Extinguished:
- Valve is open.

Question 3

Describe the meaning of an illuminated fuel FILTER BYPASS light.

(1)

Answer 3

Impending fuel filter bypass due to a contaminated filter.

Question 4

Describe the meaning of a fuel quantity LOW alert.

1

Answer 4

Displayed (amber) –
-fuel quantity less than 2000 lbs in related main tank.

Note: The fuel quantity digits on tank(s) with low fuel quantity turn amber.

Question 5

Describe the meaning of a fuel CONFIG alert.

2

Answer 5

Displayed (amber) –

• either engine running
• center fuel tank quantity greater than 1600 lbs; and both center fuel tank pumps producing low or no Pressure.

Note: The quantity digits on the center tank fuel quantity indicator turn amber.

Question 6

Describe the meaning of a fuel IMBAL alert.

5

Answer 6

Displayed (amber) –

• main tanks differ by more than 1000 lbs.
• displayed below main tank with lower fuel quantity.
• inhibited when airplane is on ground.
• inhibited by fuel LOW indication when both indications exist.
• displayed until imbalance is reduced to 200 lbs.

Note: The fuel quantity digits on tank with lower fuel quantity turn amber.

Question 7

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

(2)

Answer 7

• Place the engine start lever to CUTOFF.

- Pull the engine fire warning switch.

Question 8

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

(2)

Answer 8

• Center tank pumps produce higher pressure than main tank pumps, thus both engines are pressure fed from the center tank until the center tank quantity decreases to near zero.
• Thereafter, each engine is normally pressure fed from its respective main wing tank.

Note: When main tank fuel pump pressure is low, each engine can draw fuel from its corresponding main tank through a suction feed line that bypasses the pumps.