Narrative:

Aircraft was cleared for departure on runway 24 at teb via the ruudy 2 RNAV departure. Normally; I would have hand flow this departure using the FMS; but as a result of discussions pertaining to frequent altitude deviations on this specific departure during annual recurrent flight training (within the last 3-4 weeks); I elected to engage the autopilot at approximately 800 ft to 1;000 ft MSL to ensure level off at 1;500 ft MSL; climb rate at the time of engagement was approximately 1;000 FPM and airspeed was 180 KIAS; airspeed and altitude settings of 200 KIAS and 1;500 ft MSL were reverified/reset upon engagement of the autopilot. When the green 'asel' announcement on the pfd appeared; the nose pitched up rapidly and forcefully (similar to what is seen during a 'runaway pitch trim' scenario in simulator training). In the second or two it took to recognize and disengage the autopilot; the aircraft quickly passed through 1;500 ft MSL; reached a peak altitude of approximately 1;800 ft MSL before level was accomplished; the nose was quickly lowered and a descent back to 1;500 ft MSL begun. Prior to reaching 1;500 ft MSL; new york approach cleared our aircraft to continue climb to 10;000 ft MSL and asked about our altitude deviation and we advised them we had experienced an autopilot malfunction on departure. During our subsequent climbout (somewhere above 10;000 ft MSL); we cleared/reset the autopilot and reengaged it to see if there would be any further issues (which there were not). Upon returning to our home base; I contacted our director of maintenance to advise him the aircraft had experienced an autopilot hardover failure during our departure from teb in order to further discuss the issue and any potential corrective actions. The chief pilot of our company was also called and advised of the situation after speaking with the director of maintenance.

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Original NASA ASRS Text

Title: A CE-560 flight crew failed to level at 1;500 MSL per the RUUDY SID out of TEB when the autopilot started an abrupt climb when first engaged.

Narrative: Aircraft was cleared for departure on Runway 24 at TEB via the Ruudy 2 RNAV Departure. Normally; I would have hand flow this departure using the FMS; but as a result of discussions pertaining to frequent altitude deviations on this specific departure during annual recurrent flight training (within the last 3-4 weeks); I elected to engage the autopilot at approximately 800 FT to 1;000 FT MSL to ensure level off at 1;500 FT MSL; climb rate at the time of engagement was approximately 1;000 FPM and airspeed was 180 KIAS; airspeed and altitude settings of 200 KIAS and 1;500 FT MSL were reverified/reset upon engagement of the autopilot. When the green 'ASEL' announcement on the PFD appeared; the nose pitched up rapidly and forcefully (similar to what is seen during a 'runaway pitch trim' scenario in simulator training). In the second or two it took to recognize and disengage the autopilot; the aircraft quickly passed through 1;500 FT MSL; reached a peak altitude of approximately 1;800 FT MSL before level was accomplished; the nose was quickly lowered and a descent back to 1;500 FT MSL begun. Prior to reaching 1;500 FT MSL; New York Approach cleared our aircraft to continue climb to 10;000 FT MSL and asked about our altitude deviation and we advised them we had experienced an autopilot malfunction on departure. During our subsequent climbout (somewhere above 10;000 FT MSL); we cleared/reset the autopilot and reengaged it to see if there would be any further issues (which there were not). Upon returning to our home base; I contacted our Director of Maintenance to advise him the aircraft had experienced an autopilot hardover failure during our departure from TEB in order to further discuss the issue and any potential corrective actions. The Chief Pilot of our company was also called and advised of the situation after speaking with the Director of Maintenance.

Data retrieved from NASA's ASRS site as of April 2012 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.