What was found
DURING A 100 HR/ ANNUAL INSP THE AUTOPILOT PITCH TRIM SERVO BRACKET WAS FOUND TO HAVE BROKEN FREE FROM THE 90 DEGREE SUPPORT BRACKET THAT IT ATTACHES TO. THIS BRACKET IS A FACTORY INSTALLED PART FOR THE AUTOPILOT SYS AND IS RIVETED TO THE EXISTING AIRFRAME. THE PROBABLE CAUSE TO THIS FAILURE IS EXCESSIVE VIBRATION IN THIS AREA. RECOMMENDATIONS TO PREVENT A RECURRENCE WOULD BE TO INSTALL A DOUBLER BRACKET ON THE INBD SIDE OF THE ORIGINAL BRACKET TO HELP SHARE THE LOAD AND INCREASE THE SIZE OF THE MATERIAL LOCATED IN THAT AREA. (K)