I am at my wits end with this issue.... This is the deal.. This happens with about 50% of my flights.I setup flight as normal, load the aircraft within the sim, run down the checklist to the T. Flight plan is up and the Garmin navs are set to GPS.I am now pre-take off: Enter the initial assigned altitude into the G500 along with the VS. Turn the bug to RWY heading. Enable the FD/AP master switch...........I take off. Everything is normal.I click VS on the STEC to enable AP climb out (roughly 1000ft) - it works as normal.I click HDG on the STEC to have the AP hold the RWY HDG and the aircraft turns away from the HDG bug and holds a HDG 30 to 40 + degrees off. See first picture.If I turn the HDG bug, the AP always tracks 30 to 40+ degrees to the left or right.If I enable NAV on the STEC, the AP turns and tracks some random HDG. See the other two attached pictures. (The Garmin units are still on GPS mode) There is nothing I can do at this point to make the AP track the magenta line. If I exit out of the flight and re-create it again, it works 9/10 times.This is driving me crazy since by the time I get to this point in the flight I already have invested 30-40 minutes planning and running through checklists.Any Ideas? Sorry about the photo quality, i grabbed my phone and snapped a few pics before Killed the flight.Thanks

Edited February 11, 201214 yr by FLIGHTO

How about posting the detail of the flight plan so that we can simulate what you doing. I have never seen the behavior you describe.

If it works when you exit the sim and re-enter...Then try loading a default aircraft first, [engines on and avionics set to nav not gps] then using the "Alt" menu to select the Malibu.

Edited February 11, 201214 yr by martin-w

HI all,I can see I'm not the only one having this problem(I can fly my pmdg NGX without any problem).I love this plane but the biggest drawback is the lack of tutorial regarding how to use the avionics properly.1 what is the trim setting.2 the course on the gps is 3453 I have the ALT at 5000 feet4 I am on the runway with HDG 245 (runway HDG)5 FD off, AP off, STEC nothing selected .6 What is the correct procedure let us say to climb to 1000 feet and then to intercept the 345 radial to the first waypoint.The 530 is on vloc.Thanking you in advance.AlainV

I was having this problem also until I reset the heading indicator by pressing "D" on my keyboard. I think this resets the gyros. For some reason, this happens more to me in the Malibu than any other aircaft. Once I started pressing "D" as part of my preflight, I have not had the wandering autopilot problem reappear.

The use of the 'D' is a good habit indeed. Although I have the gyro drift off in the FSX realism options, some detailed gauges like on the Malibu or my Lancair still drift if not pressing D in certain intervals. Could be my system of course, but I think Lifeguard's tip is a very good one.

I will try the keypress when I get home. I really hope its that simple....

If the D key fixes it, I can add that to the AP initialization sequence and send you an AP mod..Let me know!

Will do.....Ill be home in a couple hours...Ill recreate some flight plans..

Did you make it home?I'm beginning to worry about you... :(

Did you make it home?I'm beginning to worry about you... :(

LMAO....Yeah Im ok..... I just finished my third flight.. I have been flying this plane all day....It seems that the "D" keypress did the trick....Why do you think this happens to this plane only....

The gauge can define how much it is susceptible to gyro drift - so this one may havechosen to be more, rather than less, I do not know.But I have now added a gyro reset to my autopilot startup sequence, so if you would liketo test it, send me your email address via a PM.

Sent, Thanks Bert

hi.I'm having a problem with the navigation in PA46.Every time when I long to start the takeoff the AP no longer follows the flight plan included in the main screen of FSX.I put the GPS NAV mode and start the AP, but the plane did not follow the magenta line and go to any point on the map and begins to circulate.The cursor HDG also presents issues because it is about 20 degrees off the actual course indicated.Same times when I take off it does not happen.Can anyone help me?

Looks Like your in Vlok change to GPS should work