Has anyone experienced the following?: After a few minutes of level flight, while on Autopilot, your aircraft all of sudden loses complete control and will pitch up or down violently - sometimes cartwheel end over end or invariably into a spin. Despite disengaging the AP and trying to regain manual control, it is impossible to do so. I also notice a massive fluctuation in the ASI before it happens. It is as if the Autopilot has gone whacko! I am also using FS Navigator and Weather Center real weather software. At first I thought the aircraft was being hit by a strong jetstream and it was virtually getting knocked over. I've tried disengaging FS9 and Weather Centrer, to see if this helps and it does not, which leads me to believe there is a bug of some sort with the autopilot. This happens with every single aircraft (default and add on). Can somebody PLEASE help? I am at wits end! This has only just started happening in the past 2 weeks. Thanks

This is a new one on me.Have no solutions to offer.Wycliffe

pitot heat on?Allcott

Are you using real-world weather or any third-party weather generators?Does it happen in clear weather (no winds)?

Hello .. It happens in all conditions and usually about 5-10 minutes after reachiung cruising altitiude. Last night I tried running a flight CYYZ-KLGA and did so without using FS9 default Real Weather download vis a vis Weather Center 2.0 and there was no incident; however, I must warn that this problem has occured before when I wasn't running Weather Centre. What I notice is that the plane all of a sudden will leap into overspeed (as if being hit from behind by a massive tail wind and this increase the ASI. Sometimes, it is the opposite... there wil be a dramatic decrase in airspeed that will induce a stall. There seems to be a constant pulsing to the airspeed while in flight and the aircraft will yaw from side to side or pitch up and down. It is as if it is severe turbulance to the extreme. I disable all wind and turbulence effects in FSUIPC (latest version) and that has no bearing. When the plane spirals out of control, the sim seems to speed up and the aircraft is completely uncontrollable. I am at a loss but there is definitely something affecting the Autoflight System (whether I'm using FS Navigator or not). Any Ideas. BTW I do not usually toggle the Pitot Heat because I have the aircraft realism settings to failsafe. Any Ideas? :-zhelp

Hi!A good start in every debugging process is to get rid of every addon (like you already have started by removing the weather addon). Try removing the FSUIPC dll as well. Then if you get rid of the problem, put them back one by one until it reappears ...brEagle

I'm certainly not an expert at this, nor am I a real-life pilot - but I have experienced this before, and it goes away when I switched on both the Pitot heat and De-icing - I don't know what the basis behind it is, but just that among all of the things that I tried, this is what worked.Hope that helps.

I wonder if the failsafe setting could cause this?