Narrative:

At FL360 in smooth air and level flight I decided to try to get the last 300 pounds of gas out of the center tank. After turning on the center tank boost pumps; the center tank boosts pump lights never went out and as I stared at them; I noticed the right main tank fwd boost pump light would flicker and then stay on steady. The light flickered off and on again and stayed on this time. A moment later the right main aft boost pump lights flickered and stayed on. Now I have two right main boost pumps light on and staying on. I pull out the QRH and it tells me to descend to 30000 ft or risk possible flameout. At this time both lights to out and we request 30000 ft for safety sake. Through ACARS we request maintenance meet us in lax. At the gate in lax mechanic came to the cockpit and we informed him of the problem. As the mechanics looked through the problem; they contacted maintenance control and were told of a history of fuel quantity indication problems with the right main tank. After several mins of visiting with the mechanic over this problem; I was told they would drip the right main tank and we would be good to go. I was very uncomfortable with this as I was sure fuel quantity and fuel boost pump pressure were two separate items. As we continued this conversation and as I talked to maintenance control; I still was not satisfied with their answer. The mechanic did not want to put this in the logbook! Being a very new captain; I was not comfortable with this either. First; we were now late. Two; we wanted something in the book about the boost pumps. I was very adamant about boost pumps and fuel quantity being two different problems. They were suggested meling the right main fuel quantity gauge. I was sure this would not satisfy any problem we were having. I called a chief who was on call and he suggested a write-up that would cover both fuel boost pumps and fuel quantity. Finally; after a 35 min delay we came to a conclusion and pushed the gate. In the end; I called the safety board because I was not sure this write-up was enough. I found out that the write-up satisfied the FAA. By the way; we stayed below FL300 the rest of the day for safety sake! Because I requested that this was written up; the aircraft would be pulled a few days later and both boost pumps replaced. Callback conversation with reporter revealed the following information: reporter advised the right wing tank boost pump low pressure lights remained on for about 10 seconds total. His descent was precautionary in nature. He was at a loss to explain why the appearance of the right tank lights came on when he turned on the center tank pumps. Although the center tank's pumps are 'override' pumps which; by virtue of their fuel pressure; force the engine to feed from the center vice associated wing tank; the act of powering them doesn't normally result in a low pressure indication in the associated wing tank. He emphasized his conviction that the problem was pump related and not a function of the previously recorded fuel quantity indication problem in that tank. He insisted that the separate write-up for the boost pumps be addressed by maintenance. The sign off by maintenance was that the pumps ground check ok. He further advised the company had decided to replace the pumps as a precaution several days later. He hoped to learn the results of inspections on the removed pumps.

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Original NASA ASRS Text

Title: ATTEMPTING TO BURN LAST 300 LBS OF FUEL IN THE CTR TANK; B737-300 FLT CREW ENCOUNTERS MALFUNCTIONING BOOST PUMPS. DISAGREEMENT ENSUES BETWEEN CAPT AND MAINT REGARDING WRITE-UP AND FIX.

Narrative: AT FL360 IN SMOOTH AIR AND LEVEL FLT I DECIDED TO TRY TO GET THE LAST 300 LBS OF GAS OUT OF THE CTR TANK. AFTER TURNING ON THE CTR TANK BOOST PUMPS; THE CTR TANK BOOSTS PUMP LIGHTS NEVER WENT OUT AND AS I STARED AT THEM; I NOTICED THE RIGHT MAIN TANK FWD BOOST PUMP LIGHT WOULD FLICKER AND THEN STAY ON STEADY. THE LIGHT FLICKERED OFF AND ON AGAIN AND STAYED ON THIS TIME. A MOMENT LATER THE R MAIN AFT BOOST PUMP LIGHTS FLICKERED AND STAYED ON. NOW I HAVE TWO R MAIN BOOST PUMPS LIGHT ON AND STAYING ON. I PULL OUT THE QRH AND IT TELLS ME TO DSND TO 30000 FT OR RISK POSSIBLE FLAMEOUT. AT THIS TIME BOTH LIGHTS TO OUT AND WE REQUEST 30000 FT FOR SAFETY SAKE. THROUGH ACARS WE REQUEST MAINT MEET US IN LAX. AT THE GATE IN LAX MECH CAME TO THE COCKPIT AND WE INFORMED HIM OF THE PROB. AS THE MECHS LOOKED THROUGH THE PROB; THEY CONTACTED MAINT CTL AND WERE TOLD OF A HISTORY OF FUEL QUANTITY INDICATION PROBS WITH THE R MAIN TANK. AFTER SEVERAL MINS OF VISITING WITH THE MECH OVER THIS PROB; I WAS TOLD THEY WOULD DRIP THE R MAIN TANK AND WE WOULD BE GOOD TO GO. I WAS VERY UNCOMFORTABLE WITH THIS AS I WAS SURE FUEL QUANTITY AND FUEL BOOST PUMP PRESSURE WERE TWO SEPARATE ITEMS. AS WE CONTINUED THIS CONVERSATION AND AS I TALKED TO MAINT CTL; I STILL WAS NOT SATISFIED WITH THEIR ANSWER. THE MECH DID NOT WANT TO PUT THIS IN THE LOGBOOK! BEING A VERY NEW CAPT; I WAS NOT COMFORTABLE WITH THIS EITHER. FIRST; WE WERE NOW LATE. TWO; WE WANTED SOMETHING IN THE BOOK ABOUT THE BOOST PUMPS. I WAS VERY ADAMANT ABOUT BOOST PUMPS AND FUEL QUANTITY BEING TWO DIFFERENT PROBS. THEY WERE SUGGESTED MELING THE R MAIN FUEL QUANTITY GAUGE. I WAS SURE THIS WOULD NOT SATISFY ANY PROB WE WERE HAVING. I CALLED A CHIEF WHO WAS ON CALL AND HE SUGGESTED A WRITE-UP THAT WOULD COVER BOTH FUEL BOOST PUMPS AND FUEL QUANTITY. FINALLY; AFTER A 35 MIN DELAY WE CAME TO A CONCLUSION AND PUSHED THE GATE. IN THE END; I CALLED THE SAFETY BOARD BECAUSE I WAS NOT SURE THIS WRITE-UP WAS ENOUGH. I FOUND OUT THAT THE WRITE-UP SATISFIED THE FAA. BY THE WAY; WE STAYED BELOW FL300 THE REST OF THE DAY FOR SAFETY SAKE! BECAUSE I REQUESTED THAT THIS WAS WRITTEN UP; THE ACFT WOULD BE PULLED A FEW DAYS LATER AND BOTH BOOST PUMPS REPLACED. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR ADVISED THE R WING TANK BOOST PUMP LOW PRESSURE LIGHTS REMAINED ON FOR ABOUT 10 SECONDS TOTAL. HIS DSCNT WAS PRECAUTIONARY IN NATURE. HE WAS AT A LOSS TO EXPLAIN WHY THE APPEARANCE OF THE R TANK LIGHTS CAME ON WHEN HE TURNED ON THE CTR TANK PUMPS. ALTHOUGH THE CTR TANK'S PUMPS ARE 'OVERRIDE' PUMPS WHICH; BY VIRTUE OF THEIR FUEL PRESSURE; FORCE THE ENGINE TO FEED FROM THE CTR VICE ASSOCIATED WING TANK; THE ACT OF POWERING THEM DOESN'T NORMALLY RESULT IN A LOW PRESSURE INDICATION IN THE ASSOCIATED WING TANK. HE EMPHASIZED HIS CONVICTION THAT THE PROB WAS PUMP RELATED AND NOT A FUNCTION OF THE PREVIOUSLY RECORDED FUEL QUANTITY INDICATION PROB IN THAT TANK. HE INSISTED THAT THE SEPARATE WRITE-UP FOR THE BOOST PUMPS BE ADDRESSED BY MAINT. THE SIGN OFF BY MAINT WAS THAT THE PUMPS GND CHK OK. HE FURTHER ADVISED THE COMPANY HAD DECIDED TO REPLACE THE PUMPS AS A PRECAUTION SEVERAL DAYS LATER. HE HOPED TO LEARN THE RESULTS OF INSPECTIONS ON THE REMOVED PUMPS.

Data retrieved from NASA's ASRS site as of January 2009 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.