AN A320 FLIGHT CREW WAS DISPATCHED WITH A CENTER FUEL TANK BOOST PUMP INOPERATIVE; AND EXPERIENCED DIFFICULTY MAINTAINING FUEL BALANCE USING FLIGHT MANUAL PROCEDURES.

Narrative

ACFT HAD CTR TANK PUMP #2 DEFERRED. THE PREVIOUS WRITE-UP INDICATED THE CTR TANK PUMP #2 HAD LOW PRESSURE ILLUMINATED WITH OVER 5000 LBS IN THE CTR TANK SO THE PUMP HAD BEEN DEFERRED. AFTER TKOF FROM ZZZ; WE REVIEWED AND EXECUTED THE PROC TO BEGIN BURNING CTR TAKE FUEL: FUEL X-FEED SWITCH ON; THEN OPERABLE CTR TANK PUMP SWITCH ON. ALTHOUGH THE L WING TANK SHOWED 11700 LBS OF FUEL; THE CTR TANK PUMP #1 SHOWED GREEN ON THE SYS PAGE BUT WAS NOT COMMANDED TO OPERATE. THE R WING TANK QUICKLY DECREASED FROM 11320 LBS OF FUEL TO 9880 LBS IN A MATTER OF ABOUT 10 MINS DURING CLBOUT. THE PUMPS IN THE R SIDE WERE CLRLY FEEDING BOTH ENGS (L TANK ROSE TO 12220 DURING THIS TIME). WE SELECTED MANUAL MODE TO GET THE CTR TANK PUMP ON TO MINIMIZE THE IMBAL. AFTER CAREFUL REVIEW OF THE FUEL SYS CHAPTER WE CLOSED THE XFEED AND SELECTED AUTOMATIC MODE AGAIN. THE CTR TANK #1 PUMP REMAINED GREEN BUT OFF. AS THE FUEL LEVEL IN THE L TANK DECREASED AGAIN TO 11700 LBS; THE CTR TANK #1 PUMP WAS COMMANDED ON AND WE THEN OPENED THE XFEED TO COMPLY WITH THE MEL. AFTER CTR TANK FUEL WAS DEPLETED; WE BALANCED THE FUEL AND THEN COMPLETED THE FLT TANK TO ENG. FOLLOWING THE MEL STEPS RESULTED IN A LARGE IMBAL THAT WAS QUICKLY APCHING THE LIMIT OF 3300 LBS. ALSO; THE L WING TANK WAS APCHING FULL AND WE WERE UNSURE BASED UPON THE INFO IN OUR FLT MANUALS WHAT WOULD HAPPEN TO THE FUEL RECIRCULATING FROM THE IDG ONCE THE TANK WAS COMPLETELY FULL. DISCUSSED WITH MAINT CTL AND LCL MAINT AT LENGTH AFTER LNDG AT ZZZ1 AND THE REMAINING CTR TANK PUMP WAS ALSO DEFERRED.