What was found
AT ALTITUDE LEVEL FLIGHT, FL 350, STEADY STATE FLIGHT CONDITIONS, AUTOPILOT A DISCONNECTED FOR NO REASON. ACFT GROUNDED. PERFORMED DFCS BITE CURRENT STATUS AND FLIGHT HISTORY FAULT REVIEW, REF FIM 22-11, TASK 801. NO CURRENT FAULTS FOUND. FOUND AUTOPILOT DISCONNECT FAULT FOR CHANNEL-A, ALT HOLD, LNAV ENGINE MCP DATA INV MESSAGE 22-11607. 1 OCCURRENCE. PERFORMED LRU TEST FOR GROUP 20.00. NO FAULTS FOUND. PERFORMED EXTENDED MAINTENANCE TESTS GROUP 70.00, IAW FIM 22-11, TASK 817. NO FAULTS FOUND. PERFORMED LAND VERIFY LIBRARY BITE TEST, IAW AMM 22-11-00/201, AND HGS SYS TEST, IAW SMM 34-36-00. NO FAULTS FOUND, IAW AMM 22-00-01.