Hey Guys,I've had this problem for a while now but I just haven't got around to asking for help with it. I found that 99% of the time I descend in the NG I rock backwards and forwards going from 2000FPM to 500FPM in a couple of seconds. In real life I'm sure there would be a few sick people. I ticked the disable turbulence and thermals on aircraft box in weather settings but that doesn't seem to help.Any ideas?

Are you using a weather program? I get a lot of porposing when using real world weather via the FSX Wx generator. I have heard that you can "smooth" the winds aloft via FSUIPC. Someone else will have to chime in on this.

I bought ASE2012 but that was just the other day. And I have FSUIPC but its not registered.

The undulating up/down motion on decent using VNAV is called "porpoising". For me it most often occurs when strong tail winds are present. It seems to force the NGX into using only pitch to control speed, and I'm not sure how this jives with RL.If it annoys me enough I switch to V/S mode which instantly solves the problem, but requires a bit more monitoring and fiddling with fpm values during the descent.

I'm flying into Venice with a 24kt tailwind right now and its going from full back elevator to full forward. So what is exactly thats causing the problem? Like I said this has happened before I updated FSUIPC and before I got ASE2012.Oh and it just stopped at around FL200

Never had this problem even when using addon weather!!I use ASE.I have turbulence enabled and thermals to naturalTry reducing the turbulence scale to 0.5 in fsx cfg.See if that helps.A registerd FSUIPC is very effective in "taming" this behaviour in fsx.,via the "winds" tab.

I've set the turbulence scale to .5 already and I don't really need a registered version of FSUIPC.