What was found
AIRCRAFT NOT GROUNDED: PILOT REPORTS DURING DESCENT AT IDLE THRUST AND FLAPS TWO, AC ROLLED LEFT AND RIGHT UNCOMMANDED, ROLL RECOVERED WHEN SPEED BRAKES WERE MOVED FROM HALF TO FULL. HAPPENED THREE TIMES. F/CTL SYS PAGE SHOWED AILERON MOVEMENT AND SYMETRICAL SPEEDBRAKE EXTENTION. AUTOPILOT WAS ENGAGED VERY SIMILAR TO WAKE TURBULANCE ENCOUNTER BUT NO AC NEARBY. MAINTENANCE PERFORMED TSM TASKS 27-10-00-810-836-A AND 27-60-00-810-851-A, ALL CHECKS NORMAL, NO FAULTS NOTED. OK FOR SERVICE.