I have posted on the DF Forum and got some assistance but nothing that works to date. With LNAV dis-engaged, it flies rock steady. With LNAV engaged my DF734 suffers from incurable rolling tendencies while above FL230. It rocks back and forth; the wings dipping better than 20 degrees rythmically. I have the latest version which includes tha cold climate update.I've tried numerous things including:re-installing FS and DFtried all different loadouts/trim/v/s and climb and cruise speedstried with default FS weather with no windstried modifying pitch and roll stability characteristics in FSEdittried many FSUIPC settingsset altitude aquiring mode in FMC to soft, moderate and hard ... and more.If ANYONE has ANY ideas, I'd be extremely grateful!TRhanks, Adam

I can't say that I have the same problem- I've got teh same aircraft with teh cold wx update too, and LNAV is steady for me (as are coupled approaches) is plain old HDG and ALT as unstable?I just flew her for the first time 2 nights ago with my new PC (had the airplane since release) and it was a dream, and I still like it better thatn an A3xx :)Tim

Adam,Are you flying with IAS or TAS set in your aircraft realism? If you are set at TAS, you might simply be flying too fast with the wrong Mach setting. In IAS, a 737-400 will typically cruise at about Mach .74 or .75Lee

Tim, Heading and ALT are completely stable. When I engage LNAV thats when it goes to s*&$^%t.Lee, I have it set as IAS.Thanks guys, Adam

LNAV is just for tracking a course. It should have nothing to do with stability. Do you have a route with waypoints loaded? Have you completely set up the FMC according to specs?VNAV will climb and descend the plane and adjust speed automatically. I'm just asking questions, just in case we stumble on some obscure little step you might have overlooked. It happens to all of us.Lee

A bit of a long shot, but what version of FSUIPC are you using?I remember the DF guys saying that they had tested it with v2.79 and that they couldn't guarantee with newer versions.If you need v2.79, I have an old copy and can email it to you.Andy

Midnight, I'm 100% sure that the settings in the FMC are correct and identical to the flight plan. I've used this plane for well over a year now, on virtually a daily basis, and the wing rocking is a new occurance. It seems to me that the plane is having a hard time tracking the course in LNAV mode. As previously stated, it works perfectly with heading select.Andy, I would definitely like a copy of FSUIPC v2.79. The only problem of course will be that ActiveSky wxRE will not work with an older version of FSUIPC. But, I would really like it so I could use it as a diagnostic tool so to speak...so send her over please.If it works with the old version, I will have a place to work from.Thanks a lot gents, Adam

It seems to me that my problem is not with the DF air file. I did a DF/Ariane merge and used the Ariane airfile. The same problem occurs.I did get an email from Hans from DF and he told me that if the course the FMC is trying to fly is between 2 (whole #) degrees, ie. 270.5 degrees, that the plane will track back and forth between 270 amd 271 causing wing rocking.I've done the same flights in the past and had no problems.Anyway, Df is getting shelved for a while, very sad to say. :-( Thanks again for all the suggestions everyone, Adam

I've noticed the exact same problem with the PIC767 panel. When LNAV is engaged the wings rock slightly. I've never been able to fix it. I believe it started with FS2002 and has to do with panels that do not use the default FS2002 autopilot commands, but implement their own.