Narrative:

Reporting and climbing to altitude in a be-4WA; 'autoplt trim fail' light goes on when approaching assigned altitude of FL230. As aircraft approached FL224 and started leveling off (autoplt on) the pressure from the trim not keeping up with altitude/speed changes; overpwred the autoplt servos and snapped off; causing the nose to jump up an additional 10-20 degrees and overshoot the assigned altitude of FL230 by 500 ft. We then switched trim control to 'emergency' and hand-toggled nose down to get control of the aircraft and go back down to FL230.

Google
 

Original NASA ASRS Text

Title: BE400A BEECHJET FLT CREW HAS AN AUTO TRIM FAILURE DURING CLB AND LEVELOFF CAUSING AN ALTDEV.

Narrative: RPTING AND CLBING TO ALT IN A BE-4WA; 'AUTOPLT TRIM FAIL' LIGHT GOES ON WHEN APCHING ASSIGNED ALT OF FL230. AS ACFT APCHED FL224 AND STARTED LEVELING OFF (AUTOPLT ON) THE PRESSURE FROM THE TRIM NOT KEEPING UP WITH ALT/SPD CHANGES; OVERPWRED THE AUTOPLT SERVOS AND SNAPPED OFF; CAUSING THE NOSE TO JUMP UP AN ADDITIONAL 10-20 DEGS AND OVERSHOOT THE ASSIGNED ALT OF FL230 BY 500 FT. WE THEN SWITCHED TRIM CTL TO 'EMER' AND HAND-TOGGLED NOSE DOWN TO GET CTL OF THE ACFT AND GO BACK DOWN TO FL230.

Data retrieved from NASA's ASRS site as of January 2009 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.