What was found
AIRCRAFT A/P DISCONNECTED AT 13,000 FEET DURING DESCENT. AT THAT POINT HAD NO ROLL CONTROL. BOTH YOKES HELD FIRMLY BY ?. AFS OVERRIDE OFF, STILL NO ROLL CONTROL. AFTER 3-4 MINS CONTROLS RELEASED. AIRCRAFT OPERATED W/O A/P TO LANDING. FOUND -AILERON SERVO/AILERON CMD RESPONSE- FAULT MESSAGE ON FCC-2 IN FAULT HISTORY, LAST LEG. ACCOMPLISHED FIM 22-12 TASK 808. ALL CHECKS NORMAL. REPLACED DUAL AILERON SERVO AS PER AMM 22-12-01. INSPECTED AILERON CONTROL CABLES & ALL ASSOCIATED LINKAGE FOR OPERATION & CONDITION. NO DEFECTS NOTED.