What was found
DURING CLIMBOUT AND TWICE DURING CRUISE, AIRCRAFT YAWED ABRUBTLY AND UNCOMMANDED. ALL FLT CONTROL PARAMETERS CHECKED NORMAL. SET FAULTS FCC NR 1 WITH TRANS FLAG.AND FMC 1 & 2 WITH NCD. R & R NR 1 FAC AS A PRECAUTION IAW MM 22-18-34-04 AND PERFORMED AFS/LAND TEST WITH NO FAULTS. PERFORMED AUTOPILOT OPS TEST IAW MM 22-10-00-5 PARA 1D. CHECK OF PITCH TRIM AUTOTRIM CIRCUITS WITH NO FAULTS ON PITCH TRIM NR 2 PITCH TRIM, NR 1 REMAINS DEF. IAW TSM: 27-21-00 FOR UNCOMMANDED MOVEMENT AND PERFORMED CHECKS FOR CORRECT BEHAVIOR OF AUTOPILOT YAW ACTUATOR SERVO MOTORS IAW MM 22-13-27-04.AND ASM:22-13-00 CHECKED GOOD. ACFT OK FOR SERVICE.