Narrative:

Late in the climb phase of flight, I initiated the next generation center boost pump procedure to use the approximately 1400 pounds of center tank fuel. My past practice had always been to use the quick reference steps as a checklist to comply with the requirements of the latest bulletin regarding the next generation center boost pump procedure. This practice had resulted in error-free performance on my part in accomplishing the procedure steps. This time, with the bulletin in hand, but without the quick reference memo, I believed that I would be able to accomplish the few, simple steps without error. I flat missed opening the xfeed and with 1 center tank boost pump on, and one off, I induced a lateral imbal. I also didn't ask the first officer to follow me through on the steps. I continued to monitor the center tank as it emptied and when I turned off the remaining center tank pump, at the first wink from the low pressure light, I realized my mistake. The amber 'imbal' message on the #2 main tank fuel gauge then illuminated and we were then 1000 pounds out of balance. I called out my observation to the first officer and with him monitoring, I immediately took the correct steps to begin fuel balancing. I observed the imbal to be 80 pounds over the maximum. The main tank fuel was then re-balanced and no adverse flight characteristics were detected. At the completion of the flight, I conferred with maintenance and made a maintenance logbook entry documenting the exceedence. Overall, fatigue may also have been a contributing factor: 8 hours of duty, on the third leg, 6 hours total block time, and after nightfall at the time of the event. The lesson I learned is that there is every reason to always use every tool that is available to us. I am back to using my quick reference memo like an abnormal checklist, ensuring that the first officer confirms each of my actions.

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Original NASA ASRS Text

Title: A B737-700 CREW INDUCED A 1000 LBS FUEL IMBAL BECAUSE A FUEL BOOST PUMP PROC WAS NOT ADHERED TO.

Narrative: LATE IN THE CLB PHASE OF FLT, I INITIATED THE NEXT GENERATION CTR BOOST PUMP PROC TO USE THE APPROX 1400 LBS OF CTR TANK FUEL. MY PAST PRACTICE HAD ALWAYS BEEN TO USE THE QUICK REF STEPS AS A CHKLIST TO COMPLY WITH THE REQUIREMENTS OF THE LATEST BULLETIN REGARDING THE NEXT GENERATION CTR BOOST PUMP PROC. THIS PRACTICE HAD RESULTED IN ERROR-FREE PERFORMANCE ON MY PART IN ACCOMPLISHING THE PROC STEPS. THIS TIME, WITH THE BULLETIN IN HAND, BUT WITHOUT THE QUICK REF MEMO, I BELIEVED THAT I WOULD BE ABLE TO ACCOMPLISH THE FEW, SIMPLE STEPS WITHOUT ERROR. I FLAT MISSED OPENING THE XFEED AND WITH 1 CTR TANK BOOST PUMP ON, AND ONE OFF, I INDUCED A LATERAL IMBAL. I ALSO DIDN'T ASK THE FO TO FOLLOW ME THROUGH ON THE STEPS. I CONTINUED TO MONITOR THE CTR TANK AS IT EMPTIED AND WHEN I TURNED OFF THE REMAINING CTR TANK PUMP, AT THE FIRST WINK FROM THE LOW PRESSURE LIGHT, I REALIZED MY MISTAKE. THE AMBER 'IMBAL' MESSAGE ON THE #2 MAIN TANK FUEL GAUGE THEN ILLUMINATED AND WE WERE THEN 1000 LBS OUT OF BAL. I CALLED OUT MY OBSERVATION TO THE FO AND WITH HIM MONITORING, I IMMEDIATELY TOOK THE CORRECT STEPS TO BEGIN FUEL BALANCING. I OBSERVED THE IMBAL TO BE 80 LBS OVER THE MAX. THE MAIN TANK FUEL WAS THEN RE-BALANCED AND NO ADVERSE FLT CHARACTERISTICS WERE DETECTED. AT THE COMPLETION OF THE FLT, I CONFERRED WITH MAINT AND MADE A MAINT LOGBOOK ENTRY DOCUMENTING THE EXCEEDENCE. OVERALL, FATIGUE MAY ALSO HAVE BEEN A CONTRIBUTING FACTOR: 8 HRS OF DUTY, ON THE THIRD LEG, 6 HRS TOTAL BLOCK TIME, AND AFTER NIGHTFALL AT THE TIME OF THE EVENT. THE LESSON I LEARNED IS THAT THERE IS EVERY REASON TO ALWAYS USE EVERY TOOL THAT IS AVAILABLE TO US. I AM BACK TO USING MY QUICK REF MEMO LIKE AN ABNORMAL CHKLIST, ENSURING THAT THE FO CONFIRMS EACH OF MY ACTIONS.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.