Recall the function of the FUEL QTY A/B button
Selects the alternate channel of the fuel quantity gauging system
Recall the function of the FUEL SYS TEST button
Button is a MAINTENANCE function only – no crew action required. When pushed
and held, starts a fuel system test display on the FUEL SD
Recall the function of the START PUMP
A DC start pump, located in the right main tank, provides fuel pressure for starting the APU or engines when AC power is not available
Recall the function of the FUEL USED RESET button
Resets fuel used digits on the fuel synoptic
Recall approximate fuel tank capacities
Left Wing Tank: 9,266 lbs
Center Wing Tank: 6,077 lbs
Right Wing Tank: 9,266 lbs
TOTAL: 24,609 lbs
Recall the number of fuel pumps available for each tank
- Each main tank uses two AC boost pumps arranged in parallel
- The center tank has two identical pumps arranged in series
- Normally, fuel from the left tank feeds the left engine and fuel from the right tank feeds the right engine, however, if center tank fuel is present, the higher pressure produced by the center pumps will allow the center tank to feed both engines
Recall the Fuel Return to Tank (RTT) process
• Excess warmed fuel cycling through the engine fuel system is returned to the inboard, cooled corner of each main tank
• This process warms the fuel in the tank and retards wing ice formation due to cooled fuel
• Fuel return to tank flow may be inhibited by the EEC for many reasons, including:
takeoff, landing, main tank fuel low, or high fuel temperature
Describe the use of FUEL X-FEED lever
A FUEL X-FEED lever, on the pedestal, permits routing of fuel from either main fuel tank to one or both operating engines. Cross-feeding is enabled when the valve is opened and the boost pumps on the receiving side are turned off
Recall features of the Fuel Venting system
- The fuel vent system permits equalization of pressure between tanks during all fuel conditions and also prevents siphoning and spilling of fuel during normal flight and ground maneuvers
- Right and Left main tanks are vented to the center tank. This also permits overflow from the main tanks to drain into the center tank during fuel return to tank operation with the main tanks full
- Center tank fuel is vented to the wingtip vent boxes
Recall how the APU is supplied fuel
The APU normally is supplied fuel from the right main tank, however, if the center tank contains fuel and its pumps are on, the center tank will supply the APU
Recall APU fuel usage for ground operations
350 pounds/hour
