PMDG 777 loosing route tracking while enroute and turning around

[aldox62 0]

Hi All,

it happened recently a couple of times that while flying enroute the plane stopped tracking the route and began turning around in circles with varying radius around the point where the anomaly happened.

Nothing special to report, in both cases it was an overseas flight EU to US and when the issue happened (5-6 flight hours already done) I was not sitting at the PC, just discovered it when I sat back again to look at the flight status-

AP LNAV VNAV AT on, normal conditions so to say, no messages or other evidence. 

I simply disconnected and reconnected AP and the plane started again tracking correctly the route.I have a screenshot captured on Google Earth where the odd flight path is shown (FSX Google Earth Tracker utility was running) but I don't have a web site to post it...

Any ideas on the reason for this behavior ? As it happens rarely and randomly it's not really easy to spot it when it happens or even plan for spotting it !

 

Many thanks in advance for any hint you may offer !

Regards,

Aldo

[Bob Scott 7,719]

If you have the turbulence settings up too high, or if you are using aggressive time acceleration (>4X) the plane can start to oscillate laterally...it can get wild enough to miss a waypoint and then it will try to circle back to it.

PMDG has some guidance on how to set up weather add-ons to prevent this from getting out of hand, and their auto-acceleration works pretty well to detect and reduce acceleration temporarily when things get unstable.

 

[aldox62 0]

Thank you for the prompt comment, I wasn't using acceleration. How can I reduce turbulence settings ?

Thanks