What was found
AIRCRAFT VERY DIFFICULT TO TRIM PROPERLY. REQUIRED OVER 2 UNITS OF LEFT AILERON TRIM, AND OVER 1 UNIT OF L RUDDER TRIM. NR 1 FUEL TANK GAUGE INOP, WAS FUELED TO A KNOWN QTY. A FUEL IMBALANCE COULD HAVE BEEN PART OF THE PROBLEM THOUGH WE COULD NOT TELL. WHEN ACFT ARRIVED AT SGF, NR 1 FUEL QTY INDICATOR WAS DEFERRED AND THE TANK WAS EMPTY, COMPARED TO NR 3 TANK, WHICH HAD A QTY OF 5900 LBS RESULTING IN A FUEL IMBALANCE OF APPROX 5900 LBS AND TRIM PROBLEM. A/C OK FOR SERVICE.