Hotfix 1.4.3 installed / Steam version / Windows 10 up to date. pms50 GTN750 (free) and TDS GTN750xi are both most current. 

As aircraft approaches waypoint (less than 2-miles) at cruise speed of about 165 IAS the waypoint message appears showing the track to the next waypoint.  The autopilot then commands a LEFT turn (every time - even if new track is just a few degrees to the right) and begins a steep descent reaching -3000 fpm within 15-seconds.  If I pull the throttle back to idle and am high enough (AGL) the plane will make one or two complete turns and eventually settle on the correct new course.  Other times the AP just keeps circling and descending, eventually hitting ground or over stressing the frame.

The same thing happens on a stabilized ILS approach at 100 IAS and slowing.  The plane is within a 1/4 dot of vertical and horizontal guidance.  The green GS is illuminated.  At about 1 mile from touchdown the AP rolls the plane left and begins descending. 

This happens with the pms50 GTN750 and with the TDS GTN750xi.  

I posted about this in the "issues" thread but received no response.  Any help would be appreciated.  

Edited April 11, 20224 yr by TacomaSailor

37 minutes ago, TacomaSailor said:

This happens with the pms50 GTN750 and with the TDS GTN750xi.  

For the TDS version, you can try my mod, posted here on this forum, it uses the Beta 1.4.0. autopilot code and is stable for me.

It appears your mod did the trick. I have made about 10-flights with four to six waypoints in each and no left descending turn problems.

Thank You Bert!

Edited April 15, 20224 yr by TacomaSailor