What was found
AFTER GEAR SELECTED DOWN, AIRCRAFT STARTED UNCONTROLLED ROLL LT (AUTO-PILOT OFF), STOPPED AFTER 5 SECONDS. THEN HAPPENED SECOND AND THIRD TIME 3 MILE END-TO-END TRAILING B737. ALL ROLLS TO LT. M/C (FIRST TIME FLAPS AT 0. SECOND FLAPS AT 20, THIRD FLAPS. PERFORMED VISUAL INSPECTION OF EXTERIOR OF AIRCRAFT INCLUDING FLIGHT CONTROL SURFACES. NO DEFECTS FOUND. PERFORMED SYSTEM SECU BITE CHECK IAW MM AND CHECKED MOVEMENT OF FLAPS AND AILERONS ALL SYSTEMS CHECKS GOOD. (K)