Narrative:

Aircraft was late to gate due to maintenance and taxi from maintenance hangar. Aircraft arrived with left fuel indicator placarded inoperative and APU inoperative. At gate; maintenance personnel noticed fluid leaking from left engine; troubleshot by actuating starter using ground pneumatic carts; and found engine driven hydraulic pump needed replacement. During maintenance actions to right&right hydraulic pump; I accomplished exterior preflight inspection; and most of cockpit preflight inspection (FMC programming not done at that time). Maintenance tested left hydraulic pump by starting left engine. Engine start was initiated at 15-16 psi duct pressure; which I mentioned to maintenance tech as below our flight crew mins. Engine start successful but maintenance personnel finish up logbook entries; and take steps to comply with MEL for the fuel tank indicator inoperative. This involves; among other things; sticking the affected tank before fueling and sticking all tanks after fueling; to manually confirm amount of fuel on aircraft. Fuel slip delivered. Reviewing fuel slip; stick readings before fueling were noted; no notation of stick readings after fueling was made. Captain was told by maintenance that stick readings were taken; we discussed that without stick readings after fueling we had no fuel total with which to manually update FMC fuel (required). Maintenance returned to aircraft; apparently misunderstood MEL procedure; confirmed that only left tank had stick reading taken after fueling. Maintenance took stick readings of all tanks; notations properly made to fuel slip; and we departed. APU placarded and inoperative; left fuel indicator placarded and inoperative (due to fluctuating readings on two previous write-ups); hydraulic pump repaired and signed off. During to and climb; left egt noted to be 50 degrees higher than right egt. Logbook entry made and event record taken. Shortly after leveloff; began noticing what we thought were fluctuating left fuel tank readings. Not unexpected considering the write-ups and placard. Not long thereafter; aircraft required increasing amounts of left rudder trim to maintain neutral aileron inputs. Disengaged ap; zeroed out rudder trim; right wing drops noticeably with no control inputs; as though heavier than the left wing. While analyzing the problem; captain notices that crossfeed valve is open; apparently left that way by maintenance and not caught by us since I had accomplished cockpit preflight prior to maintenance. Crossfeed valve closed; condition diagnosed as fuel imbalance. Decision made to burn fuel from right tank. Fuel imbalance begins to correct; rudder trim gradually reduced to near normal. Uneventful after that.

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Original NASA ASRS Text

Title: B767-200 FLT CREW HAS FUEL IMBALANCE ENRTE.

Narrative: ACFT WAS LATE TO GATE DUE TO MAINT AND TAXI FROM MAINT HANGAR. ACFT ARRIVED WITH L FUEL INDICATOR PLACARDED INOP AND APU INOP. AT GATE; MAINT PERSONNEL NOTICED FLUID LEAKING FROM L ENG; TROUBLESHOT BY ACTUATING STARTER USING GROUND PNEUMATIC CARTS; AND FOUND ENG DRIVEN HYD PUMP NEEDED REPLACEMENT. DURING MAINT ACTIONS TO R&R HYDRAULIC PUMP; I ACCOMPLISHED EXTERIOR PREFLT INSPECTION; AND MOST OF COCKPIT PREFLT INSPECTION (FMC PROGRAMMING NOT DONE AT THAT TIME). MAINT TESTED LEFT HYD PUMP BY STARTING LEFT ENG. ENG START WAS INITIATED AT 15-16 PSI DUCT PRESSURE; WHICH I MENTIONED TO MAINT TECH AS BELOW OUR FLT CREW MINS. ENG START SUCCESSFUL BUT MAINT PERSONNEL FINISH UP LOGBOOK ENTRIES; AND TAKE STEPS TO COMPLY WITH MEL FOR THE FUEL TANK INDICATOR INOP. THIS INVOLVES; AMONG OTHER THINGS; STICKING THE AFFECTED TANK BEFORE FUELING AND STICKING ALL TANKS AFTER FUELING; TO MANUALLY CONFIRM AMOUNT OF FUEL ON ACFT. FUEL SLIP DELIVERED. REVIEWING FUEL SLIP; STICK READINGS BEFORE FUELING WERE NOTED; NO NOTATION OF STICK READINGS AFTER FUELING WAS MADE. CAPT WAS TOLD BY MAINT THAT STICK READINGS WERE TAKEN; WE DISCUSSED THAT WITHOUT STICK READINGS AFTER FUELING WE HAD NO FUEL TOTAL WITH WHICH TO MANUALLY UPDATE FMC FUEL (REQUIRED). MAINT RETURNED TO ACFT; APPARENTLY MISUNDERSTOOD MEL PROC; CONFIRMED THAT ONLY L TANK HAD STICK READING TAKEN AFTER FUELING. MAINT TOOK STICK READINGS OF ALL TANKS; NOTATIONS PROPERLY MADE TO FUEL SLIP; AND WE DEPARTED. APU PLACARDED AND INOP; L FUEL INDICATOR PLACARDED AND INOP (DUE TO FLUCTUATING READINGS ON TWO PREVIOUS WRITE-UPS); HYD PUMP REPAIRED AND SIGNED OFF. DURING TO AND CLB; L EGT NOTED TO BE 50 DEGS HIGHER THAN RIGHT EGT. LOGBOOK ENTRY MADE AND EVENT RECORD TAKEN. SHORTLY AFTER LEVELOFF; BEGAN NOTICING WHAT WE THOUGHT WERE FLUCTUATING L FUEL TANK READINGS. NOT UNEXPECTED CONSIDERING THE WRITE-UPS AND PLACARD. NOT LONG THEREAFTER; ACFT REQUIRED INCREASING AMOUNTS OF L RUDDER TRIM TO MAINTAIN NEUTRAL AILERON INPUTS. DISENGAGED AP; ZEROED OUT RUDDER TRIM; RIGHT WING DROPS NOTICEABLY WITH NO CONTROL INPUTS; AS THOUGH HEAVIER THAN THE L WING. WHILE ANALYZING THE PROB; CAPT NOTICES THAT CROSSFEED VALVE IS OPEN; APPARENTLY LEFT THAT WAY BY MAINT AND NOT CAUGHT BY US SINCE I HAD ACCOMPLISHED COCKPIT PREFLT PRIOR TO MAINT. CROSSFEED VALVE CLOSED; CONDITION DIAGNOSED AS FUEL IMBALANCE. DECISION MADE TO BURN FUEL FROM R TANK. FUEL IMBALANCE BEGINS TO CORRECT; RUDDER TRIM GRADUALLY REDUCED TO NEAR NORMAL. UNEVENTFUL AFTER THAT.

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.