This has happened with both the ngx and the 747x. Im using active sky weather and the latest fsuipc (non registered). In the middle of the flight the aircraft will just start climbing anywhere from 3000 to 8000fpm. I disengage autopilot and change the trim and the aircraft is still very resistant to descend. I read a post about this somewhere else but it didn't answer my question.and usually 5 minutes or so later the aircraft will correct itself and begin descending to its assigned altitude.

Try recalibrating your controls. Same thing happened with me and the 744. It got to a point where I was stalling and she didn't respond to anything.

Try recalibrating your controls. Same thing happened with me and the 744. It got to a point where I was stalling and she didn't respond to anything.

Unfortunetely that didnt fix it. I even unplugged the yoke and pedals during autopilot to see if that would do it. still climbing and descending.

Are you overspeeding cause of a dramatic wind shift? FSX is famous for this and the plane will start climbing to bleed off speed to get you outta the redline, and then will go back to the original altitude.Try customizing your settings according to the tutorial below.http://forum.avsim.net/topic/350389-my-weather-config-for-pmdg-planes-part-ii/

Are you overspeeding cause of a dramatic wind shift? FSX is famous for this and the plane will start climbing to bleed off speed to get you outta the redline, and then will go back to the original altitude.Try customizing your settings according to the tutorial below.http://forum.avsim.n...planes-part-ii/

No Im using ASE weather to prevent those crazy wind shifts that will cause a stall. but there is about a 90 knot headwind that is pounding the front right side of my aircraft. and I already saw that tutorial and customized the settings you listed. they did help with the s turns though.

I had the same problem which kept me from flying the 747 for almost a year. I had a CH yoke and apparently the the wheel that controls the trim was out of wack and would make the aircraft climb uncontrollably. I could not adjust it. I purchased a Saitek yoke and the problem went away.WING87

You do not have your trim on an Axis do you? Definately do not want to do this. Better to have trim on a rocker switch or pov.