Information in this Flight Crew Operations Manual (FCOM) bulletin is recommended by The Boeing Company, but may not be FAA approved at the time of writing. In the event of conflict with the FAA approved Airplane Flight Manual (AFM), the AFM shall supersede. The Boeing Company regards the information or procedures described herein as having a direct or indirect bearing on the safe operation of this model airplane.
THE FOLLOWING PROCEDURE AND/OR INFORMATION IS EFFECTIVE UPON RECEIPT
Background Information
Boeing has introduced center tank fuel system changes in production, at Production Line Number 1494 and on, with deliveries starting in May 2004. These revisions include a Master Caution system logic change, center tank fuel pump auto shutoff and CONFIG alert logic change. These system updates will be available for post-production retrofit via Boeing Service Bulletins no later than fourth quarter 2004.
The Master Caution system logic has been revised so the Master Caution lights and the FUEL system annunciator light illuminate when either center tank fuel pump indicates low pressure, as opposed to the original Master Caution system logic that requires both center tank fuel pumps to indicate low pressure before the Master Caution lights and the FUEL system annunciator light illuminate. As a result of this system logic change, Master Caution light recall will no longer cause the Master Caution and FUEL annunciator lights to illuminate if one center tank fuel pump switch is positioned OFF and the other is positioned ON.
To limit the potential for prolonged dry running of the center tank fuel pumps, a Center Tank Boost Pump Auto Shutoff system has been installed to automatically turn the affected center tank fuel pump off after 15 seconds of continuous low fuel pressure indication. The center tank fuel pump switch will remain in the ON
Flight Crew Operations Manual Bulletin No. SHZ-40, dated June 04, 2004 (continued)
position and LOW PRESSURE will be illuminated until the flight crew positions the fuel pump switch to OFF. The auto shutoff feature will individually control the center tank fuel pumps and can be manually reset by turning the respective center tank fuel pump switch OFF, then ON. If no fuel is available, the pump will again turn off after 15 seconds of continuous low pressure. This system is intended to be a backup to normal flight crew procedures.
The CONFIG alert logic has been changed so that the alert is illuminated when center tank quantity is greater than 1600 pounds/726 kilograms, either engine is running and both center tank fuel pump switches are positioned OFF.
New Normal Procedures have been developed for airplanes with the center tank fuel system changes installed. These are presented in the Operating Instructions below. However, operators may continue to use the procedures contained in AD 2002-19-52 and AD 2002-24-51, or the procedures approved in FAA Approval Letter 140S-03-189 as an Alternative Method of Compliance (AMOC), until all center tank fuel pumps have been inspected and all airplanes in their fleet have been modified. The AD 2002-19-52 and AD 2002-24-51 procedures, as well as the AMOC procedures, were discussed in detail in the Flight Crew Operations Manual Bulletin titled “AD 2002-19-52 and AD 2002-24-51, Center Tank Fuel Pumps.”
Flight Crew Operations Manual Bulletin No. SHZ-40, dated June 04, 2004 (continued)
after installation of the center tank fuel system changes at the discretion of the operator for the time period AD 2002-24-51 is in effect.
NOTE: When using the AMOC procedures on airplanes with the new Master Caution system logic, Master Caution light recall will not cause the Master Caution lights and FUEL system annunciator light to illuminate if one center tank fuel pump switch is positioned OFF and the other is positioned ON.
NOTE: The fuel crossfeed valve must be closed for takeoff and landing.
Operating Procedure 3 - Normal Procedures (Airplanes with Center Tank Fuel System Changes)
The Normal Procedures presented below may be used on those airplanes in which the center tank fuel pumps have been inspected via an approved inspection process to ensure proper wire bundle positioning (AD 2002-19-52) and in which the center tank fuel system changes have been installed in production or via Boeing service bulletins.
Climb and Cruise Procedure
During climb, position both center tank fuel pump switches OFF when one center tank fuel pump LOW PRESSURE light illuminates.
When established in a level attitude at cruise, if the center tank contains usable fuel and the center tank fuel pump switches are OFF, position the center tank fuel pump switches ON again.
Position both center tank fuel pump switches OFF when the center tank is empty.
Descent and Approach Procedure
During descent, position both center tank fuel pump switches OFF when one center tank fuel pump LOW PRESSURE light illuminates.
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