My J has a Century IIB and after flying it in heading mode for an hour the plane started to wander to the right. After reengaging the heading I found that it wouldn't follow the heading bug left or right but would stay in the original setting and then start to slowly move to the right. When I set it to nav or approach mode it wouldn't track but would still wander to the right. The roll control will work when it's in the AP mode only. Any suggestions on what's wrong?
Thanks
Steve