What was found
DURING CRUISE FL 330 "B" A/P DISCONNECTED BY ITSELF, NO HYDRAULIC ANOMALIES NOTED OR TURBULENCE. REENGAGED B A/P, WORKED FOR THE REST OF THE FLIGHT. GROUNDED - YES. DFCS GROUP 20 SHOWED TWO AUTOPILOT DISCONNECTS LOGGED BY FCC-B ON LEG 10 - ONE CAUSED BY FAULT 22-11701 "COLUMN OVERRIDE" AND ONE CAUSED BY FAULT 22-11607 "MCP DATA INVALID". FOR FAULT 22-11701, ACCOMPLISHED T/S PER B737-800 FIM 22-12 TASK 805 - PERFORMED DFCS GROUP 55 (PITCH CWS RIGGING) TEST PER AMM 22-11-00-820-806 AND GROUP 47 (PITCH SENSOR) TEST PER FIM 22-11 TASK 802 - ALL TESTS PASS. FOR FAULT 22-11607, ACCOMPLISHED T/S PER FIM 22-11 TASK 817 - PERFORMED DFCS GROUP 70 (MCP TESTS) PER FIM 22-11 TASK 803 AND DFCS GROUP 32 (MCP LRU INTERFACE) TEST PER AMM 22-11-34-740-801 - ALL TESTS PASS. PERFORMED DFCS GROUP 49 (LAND VERIFY) PER AMM 22-11-00-700-801 AND HGS SYSTEM TEST PER HGS SMM 34-36-00 - ALL TESTS PASS. AIRCRAFT IS QUALIFIED FOR CAT IIIA AUTOLAND AND HGS OPS AND STATUS PLACARD REFLECTS SAME.