Narrative:

Departing as a repo flight. The aircraft was written up the night before for a flight control malfunction. We actually had the airplane the day before and noticed that the autopilot acted a little funny at times. We both did not think it was a big deal. Apparently it had gotten worse that afternoon. I do believe that airplane actually diverted to [an alternate] for that specific reason. Before we departed maintenance control called us and informed us what the situation was and if we had any issues return back. Everything seems normal with all our originating checks. After departing we engaged the autopilot which at that point the airplane decided to roll right 20 degrees past what the heading bug was actually sent to. At this point both me and the captain decided that it was not safe to continue so we returned to the field; landed safely; and parked the airplane at maintenance. We informed maintenance and dispatch of the situation.we detected it when the autopilot was engaged and we decided it was best to return to the fieldi believe it was an issue with a servo or the autopilot itself.our maintenance crews should have probably run more tests than just an aileron alignment.

Google
 

Original NASA ASRS Text

Title: EMB-145 First Officer reported returning to departure airport after experiencing an autopilot anomaly.

Narrative: Departing as a repo flight. The aircraft was written up the night before for a flight control malfunction. We actually had the airplane the day before and noticed that the autopilot acted a little funny at times. We both did not think it was a big deal. Apparently it had gotten worse that afternoon. I do believe that airplane actually diverted to [an alternate] for that specific reason. Before we departed Maintenance Control called us and informed us what the situation was and if we had any issues return back. Everything seems normal with all our originating checks. After departing we engaged the autopilot which at that point the airplane decided to roll right 20 degrees past what the heading bug was actually sent to. At this point both me and the Captain decided that it was not safe to continue so we returned to the field; landed safely; and parked the airplane at Maintenance. We informed Maintenance and Dispatch Of the situation.We detected it when the autopilot was engaged and we decided it was best to return to the fieldI believe it was an issue with a servo or the autopilot itself.Our Maintenance crews should have probably run more tests than just an aileron alignment.

Data retrieved from NASA's ASRS site 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.