What was found
NR 1 AUTOPILOT ALTITUDE WANDERS FROM SELECTED ALTITUDE TO UP TO 800 FEET LOW. NR 1 AUTOPILOT DISENGAGED TWICE IN FLIGHT. ACFT TRIMMED NORMALLY. PERFORMED SUCCESSFUL AFS TESTS BOTH FCCS IAW MM 22-00-00-5 AND FOLLOWING RVSM FLOW CHART IAW AMM 34-10-00-2. PERFORMED PROCEDURE TO RETURN TO RVSM OPERATIONS FOR ALL RVSM COMPONENTS LISTED IN TABLE 1 OF SAME MM REFERENCE. ALL COMPONENTS CHECKED GOOD AND PER CHART ACFT WILL REQUIRE RVSM WAVINESS INSPECTION ITEM 34-10-9271 CREATED. AFTER REPAIR OF AVIONICS EQUIPMENT RACK, PERFORMED ONE FINAL OPS CHECK OF FCC'S. ALL SYSTEM OP CHECKED NORMAL AND NO DEFECTS NOTED. IAW AMM 22-00-00-5.