A B767-300 WAS FUELED WITH A 4000 LB FUEL IMBALANCE ON TAXI OUT; THE 'FUEL CONFIGN' LIGHT WAS ON. CREW CANCELLED LIGHT BELIEVING FUEL IN CTR TANK WITH PUMPS OFF WAS A NORMAL AIRWORTHINESS DIRECTIVE PROC.

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IT IS QUITE POSSIBLE THAT THE ACFT WAS INADVERTENTLY TAXIED AND FLOWN WITH A 4000 LB FUEL IMBALANCE. ALTHOUGH THE COCKPIT FUEL TOTALIZER (FUEL ON BOARD) WAS CAREFULLY CHKED AGAINST THE FLT PLAN RELEASE FUEL REQUIRED; THE APPARENT IMBALANCE OF THE INDIVIDUAL MAIN FUEL TANK QUANTITIES WAS NOT PICKED UP. THE FUEL CONFIGN WARNING SYS; WHICH WOULD HAVE ALERTED US TO THIS CONDITION; WAS CANCELLED ON TAXI OUT. TKOF WAS GOING TO BE INTO AN ACTIVE WX AREA; AND WE ELECTED TO WAIT UNTIL CRUISE FLT TO BURN THE CTR TANK FUEL DOWN TO 1000 LBS. THE FUEL CONFIGN LIGHT HAVING THE MULTI-FUNCTION OF WARNING OF ANY NUMBER OF FUEL PROBS; WE DISMISSED IT AS WARNING US OF THE OBVIOUS; IE; FUEL IN CTR FUEL TANK WITH CTR TANK FUEL BOOST PUMPS OFF. IMBALANCE WAS CORRECTED IN FLT. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED NORMALLY THE FUEL LOADS IN THE WINGS ARE CLOSELY CHKED PRIOR TO DISPATCH; BUT IN THIS CASE; A HUMAN ERROR WAS MADE THROUGH HABIT. THE RPTR SAID ON TAXI-OUT THE FUEL CONFIGN WARNING LIGHT CAME ON AND WAS CANCELLED THINKING IT WAS THE NORMAL WARNING RECEIVED WITH FUEL IN THE CTR TANK WITH PUMPS OFF. THE RPTR STATED THE FUEL IN THE CTR TANK IS A REQUIREMENT OF AN AIRWORTHINESS DIRECTIVE TO MAINTAIN THE PUMPS COVERED WITH FUEL. SUPPLEMENTAL INFO FROM ACN 590785: FUEL CONFIGN LIGHT WAS ILLUMINATED. ASSUMED IT WAS FOR THE CTR TANK PUMPS; WHICH WE ELECTED TO LEAVE OFF FOR TKOF.