I have a Garmin GNC 420, trutrak digiflite II vs and AFS 4500 in my rv-10.
When flying GPS approach, the auto pilot flys the plane 75-100 yds to one side of rwy. Also, the EFis is showing the rwy off to one side. Any suggestions.
This can happen if the airport wasn't originally surveyed very well... for instance, there's an RNAV approach to an airport near me where the missed approach waypoint is somewhat off to the side of the runway, and I've flown into small country airports whose surveyed runway position is enough in error that the runway is noticeably displayed on a synthetic vision display. Unfortunately there's not much you can do about it.
I suspect you mean the autopilot is not tracking centerline. FAA flight inspection does not commission (approve for publication) RNAV procedures with such a survey data error.
Is the airplane in coordinated (ball centered, wings level) flight?
