What was found
DURING CLIMBOUT ON FLIGHT NR 3321, AT LEVEL FLIGHT THE FLAPS BEGAN UNCONTROLLED MOVEMENT CAUSING THE AIRCRAFT TO PITCH. THE FLAP MOVEMENT WAS CONFIRMED WITH THE FLAP INDICATOR. AIR RETURN TO MSP MAINTENANCE WITH FLAPS 0 DEG, SIMULATED AIR LOAD ON FLAPS AND NOTED FLAPS EXTENDED UNCOMMANDED THEN RETRACTED. COMPLETED FLAP CONTROL RIGGING IAW AMM 27-51-00-5. RE-RIGGED FLAP CONTROL BOX AND FLAP POSITION TRANSDUCERS. REPLACED LT FLAP POSITION POTENTIOMETER 7DE PN/ON 8565M1, PN/OFF 8532, SN/ON 94040026, SN/OFF 250 IAW AMM 27-53-05 DUE TO LOOSE SHAFT.