Max Fuel Flashcards
How is fueling accomplished?
Single-point pressure fueling station located on the right wing.
The fueling station panel is energized when the panel door is open. The refueling system is powered by the hot battery bus; however, one of the following electrical sources must be available:
* External power connected, regardless if external power has been selected
* APU generator power
* Battery power (BAT switch must be ON)
What does an IMBAL alert on the Fuel Quantity Indicator indicate?
Main tank fuel quantities differ by greater than 1000 lbs for 60 seconds.
The IMBAL will display below the lower quantity fuel tank and turn the fuel quantity indication for the lower side amber.
The alert will remain until the difference between
the main tanks is 200 lbs or less.
What does the LOW alert on the Fuel Quantity Indicator indicate?
Less than 2000 lbs for 30 seconds.
The message remains until the associated main tank has greater than 2500 lbs.
What does a CONFIG alert on the Fuel Quantity Indicator indicate?
1600 lbs or more in the center tank with both center tank boost pumps OFF and an engine is running.
What does INSUFFICIENT FUEL on the Fuel Quantity Indicator indicate?
FMC fuel at the destination is predicted to be less than 2000 lbs.
With all fuel pumps operating, what ensures center tank fuel is used before main tank fuel?
Higher fuel pump output pressure from the center tank pumps ensures that center tank fuel is used first, even though all pumps are operating
Center tank fuel pumps (L and R) output pressure is approximately 25-41 psi, with a minimum flow rate of 20,000 lbs per hour
Main tank fuel pumps (FWD and AFT) output pressure is approximately 10-24 psi with a minimum flow rate of 20,000 lbs per hour.
When do the center tank fuel pumps shut off automatically?
15 seconds of a continuous LOW PRESSURE light.
Turning the respective FUEL PUMPS switch OFF will
reset the automatic logic if the pump is switched back to ON. Therefore, the pump will again operate until the automatic shutoff logic is met.
How is fuel provided to the engine(s) without the fuel pumps?
A suction feed line that bypasses the pumps.
The center tank does not have the ability to suction feed.
When does the center tank fuel scavenge jet pump activate?
With main tank fuel pumps on center tank scavenge jet pumps automatically transfer residual fuel with main tank quantity decreases to 4,500lbs
How is fuel provided to the engine(s) without the fuel pumps?
With the main tank No. 1 FWD FUEL PUMPS switch ON, a center tank scavenge jet pump operates automatically to transfer any residual center tank fuel to main tank No. 1.
When main tank No. 1 fuel quantity decreases to 4500 lbs or less, a float valve to the scavenge jet pump opens and uses motive flow from the main tank No. 1 forward pump to transfer residual fuel from the center tank.
Once the scavenge process begins, it continues for the remainder of the flight, transferring 220-450 lbs per hour
What is the purpose of the crossfeed valve?
Crossfeeding is enabled from any of the fuel tanks to either engine.
The crossfeed valve is DC powered
What is the Caution! regarding “Alpha Pump” that can lead to a fuel tank imbalance? (Bonus question)
If a main tank fuel pump has a slightly higher output pressure than the other operating main tank fuel pumps, the dominant pump will provide fuel freed not only to its respective engine but also the opposite engine. This produces a higher flow rate out of the main tank with the dominate pump and a reduction in flow rate out of the opposite main tank, resulting in a fuel imbalance.
What does the engine start lever control?
Fuel flow to the engines is controlled by fuel shutoff valves located in each engine and wing spar.
The position of the fuel shutoff valves is controlled by the start levers below the throttles.
What does a bright blue illumination of the VALVE OPEN on the Fuel panel indicate?
Valve is in transit or the valve position disagrees with the selector position.
A dim blue VALVE OPEN illuminates when the valve is open with the selector positioned to open.
When the CROSS FEED selector is closed and the crossfeed valve is closed, the light is extinguished.
What does the dim illumination of an ENG VALVE CLOSED light indicate?
Valve is closed.
When the valve is open and the start levers are in IDLE, the light is extinguished.
What does a bright illumination of a SPAR VALVE CLOSED light indicate?
Valve is in transit or disagrees with the start lever or FIRE SWITCH position.
Where could the APU suction feed fuel from?
Fuel is suction-fed from main tank No. 1 only.
Where is the Nitrogen Generation System operability indicator located?
Main wheel well adjacent to the Fire Control panel.
