747-400x Autopilot Gone Mad

[Guest Marcin]

I have a problem with the autopilot in PMDG 747-400X. From time to time it becomes mad (during a flight from Cairo to Doha it happened twice). Without any reason it starts turning right and left at very high bank angle. It happens in different flight phases - 10 minutes after takeoff, at cruise, shortly before T/D. Even with HDG switched on the plane is unable to hold the direction.On this screenshot you can see what was going on:http://www.pietraszko.eu/pub/crazyautopilot1.jpgAnd here you see how my route looked like...http://www.pietraszko.eu/pub/crazyautopilot2.jpgI use a real-world weather option with 'download winds aloft data with real-world weather' option switched on. I have ProFlight Emulator Deluxe and FSUIC installed, but I don't use these two. And no other third party addons which might be important now - just few additional aircraft.Can you help me solve this problem?Greetings from Poland!Marcin.

[Fallap 4]

I have had the same problem.I dont know what caused it, but I resolved it by re-installing the aircraft.

[FlyinMisfit 0]

i'm having the same problem with a clean install (less than 1 month old) of WinXP 32-bit -2GB of Ram and FSX/PMDG747. also, had the same prob. a few months ago with WinXP 64-bit with 4GB of Ram. and a 2 month old clean install of FSX/PMDG747. using FSX RWW as well with both OS'es. any help from the PMDG folks would be greatly appreciated. happy flyin, Tim Wheeler

[downscc 1,327]

If you are not using registered copy of FSUIPC and its weather smoothing then you will have problems with msfs wx. I have my wind smoothing set to allow 1 deg/kt of change per 8 seconds. Also, you have to smooth pressure/temperatur too. All these variables with suddenly shift causing significant upsets with a hi fidelity simulator like the PMDG.Try a flight with weather clear (no weather) and see if the same thing happens. I don't expect it to.

[FlyinMisfit 0]

hi Dan,thanks for the info. i don't have a registered copy of FSUIPC. i will give it a try. btw, i don't have this problem with FS9's RWW and the PMDG747. is it something FSX RWW specific? i didn't think there was that much difference between FS9 & FSX RWW. happy flyin, Tim Wheeler

[Guest Marcin]

Turning weather smoothing on didn't solve the problem:http://www.pietraszko.eu/pub/crazyautopilot3.jpgI set wind smoothing to 1deg/kt of change per 5 seconds and pressure smoothing to default value (20 something I think).Maybe Fallap's idea to reinstall the aircraft will help...

[downscc 1,327]

hi Dan,thanks for the info. i don't have a registered copy of FSUIPC. i will give it a try. btw, i don't have this problem with FS9's RWW and the PMDG747. is it something FSX RWW specific? i didn't think there was that much difference between FS9 & FSX RWW. happy flyin, Tim Wheeler

The biggest difference, aside from vertical gust/thermal feature, is FSX added simconnect application interface with not enough bandwidth to do the job. FSUIPC didn't start working in FSX until Pete figured out how to get around it.Did you try the flight with clear weather to prove that it is a wx engine problem? If you can prove it is the weather, not the autopilot, then increase to 8-10 seconds per 1 deg/kt change. I also decreased sensitivity to pressure changes to half the default value. Last week I had problems even with all this smoothing over the N Atlantic.. the real fix is up to Microsoft (but I've lost confidence in their committment to even bother).

[FlyinMisfit 0]

Dan,what is your Temp smoothing (OAT) setting? the default is 100. i changed the Pressure smoothing to 10 from the default of 20.thanks for the help. btw, i think one of FSX (older versions as well) biggest probs. with regards to performance is Sloppy Coding - plain and simple. and, i won't be surprised if FS11 isn't any better. happy flyin, Tim Wheeler

[downscc 1,327]

Pressure 10, Temperature 50. Also check suppress turbulence, gusts and variance.

[FlyinMisfit 0]

thanks Dan. happy flyin, Tim Wheeler

[Guest Marcin]

I reinstalled the PMDG and cleared all the weather and it was all right. I will try once again today or tomorrow with real world weather and see if the reinstallation solved the problem or not. It seems it did because I noticed some other little problems were solved also.

[nhagag 26]

HiI had the same problem; the aircaft is going left/right on a flight from Darwin (YPDN) to Mumbai (VABB) using real weather.I do not have the Registered FSUIPC version. From this post it seems that everybody agrees that it is weather/wind triggered problem.In that case is registering FSUIPC a must? Because I also have the same problem in PMDG MD11, however the aircraft oscillates up and down when flying in real weather.ThanksBill

[FlyinMisfit 0]

hi Marcin,please let us know how ur flights with RWW goes. i'm still having the same prob. although, using the reg. ver. of FSUIPC with Dan's recommended settings seems to have helped alot. happy flyin, Tim Wheeler

[Guest Marcin]

Yes it's great now. Today firstly I tried without FSUIPC and it didn't work. Later I switched FSUIPC on with Dan's settings and it was great then. Previously I didn't switch suppress turbulence, gusts and variance options on so that was the problem.Thank you very much for the help. It's great now to fly this masterpiece. I can't wait for the boxed version of the MD-11.

[FlyinMisfit 0]

thanks for the update Marcin. happy flyin, Tim Wheeler