N972NA

THE IMPROPER USE OF AILERON TRIM AND THE IMPROPER PREPARATION FOR AUTO PILOT DISCONNECT BY THE FLIGHT CREW COMBINED WITH EXCESSIVE FORCES APPLIED BY THE AILERON TRIM SYSTEM RESULTING IN A DEPARTURE FROM CONTROLLED FLIGHT. CONTRIBUTING FACTORS TO THE INCIDENT WERE INADEQUATE AND MISLEADING AUTOPILOT WARNINGS, LACK OF CONSPICUITY OF THE AILERON TRIM INDICATOR, LACK OF FAA REGULATION GOVERNING CONTROL AUTHORITY IN MISTRIM CONDITIONS, AUTOPILOT SYSTEM MASKING OF MISTRIM CONDITIONS, AND THE LACK OF FAA REQUIREMENT FOR RECURRENT PILOT TRAINING IN AUTOPILOT USE.