B737 FLT CREW HAS A FUEL IMBAL AFTER TKOF AND RETURNS FOR LNDG AT TPA.

Narrative

I ARRIVED AT THE ACFT APPROX 35 MINS PRIOR TO PUSH. THE ACFT HAD OVERNIGHTED AT TPA. I RECALL THAT AN 'SC' CHK WAS DONE ON THE PLANE. THE FUELER CAME TO THE COCKPIT AND SAID THAT AN IMBAL OF FUEL WAS PRESENT ON THE ACFT. #1 TANK SHOWED 9300 LBS ONBOARD AND #2 TANK SHOWED 3500 LBS AND THE CTR TANK 40 LBS. HE ASKED WHAT WE WANTED DONE TO BAL THE FUEL LOAD. ADD FUEL IN #2 TANK TO EQUAL THE AMOUNT IN TANK #1 OR XFER SOME OF THE #1 TANK FUEL TO THE #2 TANK. I TOLD HIM TO XFER SOME OF THE #1 TANK FUEL TO THE #2 TANK; THEN ADD FUEL TO MEET FUEL REQUIREMENTS FOR DISPATCHING OF THE FLT. FUEL WAS BALANCED AT APPROX 7800 LBS PER TANK. I THEN FINISHED COCKPIT SETUP/TESTS. WE PUSHED AND WERE AIRBORNE. IMMEDIATELY AS THE ACFT BECAME AIRBORNE; IT WANTED TO ROLL TO THE R. I CORRECTED THIS ROLL USING ALL AVAILABLE FLT CTLS. ANY REDUCTION OF FLT CTL INPUTS; THE ACFT WOULD WAN TO RESUME ITS ROLLING TENDENCY TO THE R. I DISPLACED THE YOKE MORE THAN 45 DEGS (L AILERON) AND MORE THAN 4 UNITS OF L RUDDER TO CTL THE ACFT. MY EYES WENT TO LOOK AT THE ENG INST PANEL FOR ENG READINGS. I CAUGHT; S I GLANCED; THAT #1 FUEL TANK NOW READ 350 LBS AND #2 TANK WAS READING 7000 LBS. I OPENED THE FUEL XFEED VALVE AND TOLD THE FO TO ADVISE TPA TWR THAT WE NEEDED TO RETURN TO THE ARPT IMMEDIATELY FOR LNDG. WE WERE INSTRUCTED TO LEVEL OFF AT 1600 FT MSL AND ENTER A R DOWNWIND TO RWY 36R. FO NOTIFIED THE FLT ATTENDANTS ABOUT OUR RETURN T THE ARPT FOR LNDG. ALSO; HE CALLED TPA OPS TO TELL THEM WE WERE RETURNING. THE DISPATCHER TALKED TO US ON THE DOWNWIND; HE WAS INFORMED THAT WE HAD A FUEL IMBAL PROB AND WOULD BE ON THE GND SHORTLY. AN EMER WAS NOT DECLARED; JUST THAT WE NEEDED TO RETURN BECAUSE OF A FUEL IMBAL. ASYMMETRICAL THRUST WAS USED TO KEEP THE WORKLOAD OF THE FLT CTLS TO A MINIMUM ONCE THE DOWNWIND WAS ENTERED. FLAPS WERE NEVER RETRACTED FROM THE TKOF POS OF 5 DEGS. WE LANDED WITH FLAPS 15 DEGS BECAUSE I DIDN'T WANT TO INCREASE THRUST REQUIREMENTS ON APCH WITH THE USE OF A FLAPS 30/40 DEG LNDG. FO AGREED WITH THIS ASSESSMENT FOR OUR FLAPS 15 DEG LNDG. THE ACFT WAS RELATIVELY EASY TO CTL USING THIS FLAP POS ON APCH. WE COMPLETED A DSCNT APCH CHKLIST PRIOR TO THE BASE TURN. LNDG WAS NORMAL AND UNEVENTFUL. APPROX LNDG WT WAS 88300 LBS. TOTAL FLT TIME WAS 8 MINS.