What was found
ETOPS SIGNIFICANT SYSTEM - MAIN TANK XFERRED FUEL 3100LBS INTO CTR TANK. BOTH MAIN TANKS REMAINED BALANCED. TOTAL QTY IND ACCURATE (MATCHED FLT PLAN FUEL QTY) CENTER TANK QTY INCREASED TO 3100LBS OVER A 2 HR PERIOD. AS PER VERBAL FROM INBD CREW CTR TANK INCREASED JUST AFTER T/O TO APPROX 1200 LBS THEN INCREASED TO 3100 LBS. FUEL PUMPED OUT DURING FLT THEN FUEL NEVER RE-ENTERED TANK. FUEL QTY BITE CKD W/NO FAULTS. FUEL XFERRED BETWEEN TANKS & NO UNWANTED XFER. MANIFOLDS PRESS FOR 1 HR NO UNWANTED XFER. OK FOR SERVICE.