Narrative:

Aircraft was to fly a 1 hour flight. No alternate was given; and a fuel load of 50100 pounds was on board; estimated burn was 23900 pounds. Upon rotation; the forward low fuel pressure fuel light came on in tanks #1; #2; #3; and #4 and remained on until the aircraft was pitched over out of 10000 ft and accelerated through 250 KIAS. If 1 forward fuel pump is deferred; a fuel load is required of 24250 pounds in the bank in that tank per the MEL. Then why on takeoff are we being given a total fuel load of only 50000 pounds? If this is a normal occurrence on this leg; then safety dictates that a minimum fuel load of 97000 pounds is the minimum fuel load for this aircraft on certain legs or any other flight that is about 1 hour of flight time. I tried to find some information on how long you can run a main tank fuel pump uncovered but could not do so. I am assuming that running all 4 forward fuel pumps for approximately 12 mins is unacceptable. The only reference to uncovering the forward fuel pumps is a go around and the aircraft pitch is to be limited. This is not possible on takeoff and if pitch and speed are to be limited then we will not be able to make the climb gradients required for the takeoff or sids.

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Original NASA ASRS Text

Title: NEW CAPT OF B747 IS CONCERNED ABOUT EXTENDED OP OF FORWARD FUEL BOOST PUMPS WHEN NO FUEL IS AVAILABLE DUE TO HIGH BODY ANGLE ON MINIMUM FUEL; LOW GROSS WT TKOFS.

Narrative: ACFT WAS TO FLY A 1 HR FLT. NO ALTERNATE WAS GIVEN; AND A FUEL LOAD OF 50100 LBS WAS ON BOARD; ESTIMATED BURN WAS 23900 LBS. UPON ROTATION; THE FORWARD LOW FUEL PRESSURE FUEL LIGHT CAME ON IN TANKS #1; #2; #3; AND #4 AND REMAINED ON UNTIL THE ACFT WAS PITCHED OVER OUT OF 10000 FT AND ACCELERATED THROUGH 250 KIAS. IF 1 FORWARD FUEL PUMP IS DEFERRED; A FUEL LOAD IS REQUIRED OF 24250 LBS IN THE BANK IN THAT TANK PER THE MEL. THEN WHY ON TKOF ARE WE BEING GIVEN A TOTAL FUEL LOAD OF ONLY 50000 LBS? IF THIS IS A NORMAL OCCURRENCE ON THIS LEG; THEN SAFETY DICTATES THAT A MINIMUM FUEL LOAD OF 97000 LBS IS THE MINIMUM FUEL LOAD FOR THIS ACFT ON CERTAIN LEGS OR ANY OTHER FLT THAT IS ABOUT 1 HR OF FLT TIME. I TRIED TO FIND SOME INFO ON HOW LONG YOU CAN RUN A MAIN TANK FUEL PUMP UNCOVERED BUT COULD NOT DO SO. I AM ASSUMING THAT RUNNING ALL 4 FORWARD FUEL PUMPS FOR APPROX 12 MINS IS UNACCEPTABLE. THE ONLY REF TO UNCOVERING THE FORWARD FUEL PUMPS IS A GAR AND THE ACFT PITCH IS TO BE LIMITED. THIS IS NOT POSSIBLE ON TKOF AND IF PITCH AND SPD ARE TO BE LIMITED THEN WE WILL NOT BE ABLE TO MAKE THE CLB GRADIENTS REQUIRED FOR THE TKOF OR SIDS.

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.