As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AT APPROX 4 HRS AFTER DEPARTURE, THE FUEL QTY/USED CHECK LEVEL 2 ALERT DISPLAYED. OBSERVED THAT FUEL TANK QUANTITY WAS APPROX 5000 LBS LESS THAN FUEL BURN AMOUNT FROM FUEL TOTALIZER. ISOLATED ALL TANKS AND OBSERVED THAT TAIL TANK QUANTITY CONTINUED TO DECREASE AT A RATE OF APPROX 100 LBS EVERY 5 MINUTES. DEFERRED TAIL TANK ISO VLV M291016. RE-ACTIVATED TAIL TANK ISO VALVE IAW SMP PROCEDURE 28-21-19. THIS CLEARS DEFERRAL M291016.