I checked and probably missed when doing a search on the forum.  What is the solution to resolving uncommanded rolls to left and right of LNAV heading?  I'm having the same problem with the PMDG 777 too.  Wing and engine heat is on.  I tweak the trim stabilizer trim tabs to help with crosswinds.  Still have the rolls.  Welcome any guidance on this.

Are you saying the plane is continuously rolling back and forth?

 

I wouldn't touch the trim for crosswind.

 

 

What is the solution to resolving uncommanded rolls to left and right of LNAV heading?

 

What weather program are you using?

 

 

 

Wing and engine heat is on.

 

Just a note on this:

Wing and engine anti ice should only be on when icing conditions exist.  Remember that ice requires two things: cold + water.  If you don't have the second part (90% of the time), you're not going to need anti-ice.  Icing conditions are generally +10C to about -40C and visible moisture (clouds/rain/etc).

Spin and Scandinavian . . . in answer to your questions and comments.

 

1.  Anti-ice on only when atmospheric conditions dictate need for it.

 

2.  The left and right rolls begin very gently and are subtle gradually increasing to significant rolls of 20 - 25 degree.

 

3.  I'm currently using FSX "Real" Weather and REX 4 Themes.  I have OPUS Live Loaded but not in ops yet.

 

4.  Problem does not exhibit on non-PMDG add-on aircraft.  I've experienced it thus far with the PMDG 737 and 777.  I read somewhere that someone is experiencing it with the PMDG 747-400.  I've got that aircraft . . . just have not flown it since the problem began exhibiting in the 737 and 777.  I plan to run some flight checks to see if it happens . . . will also run a flight check without "Real" Weather engaged.  Naturally, I prefer to fly with real and changing weather conditions. 

 

Scandinavian . . . I was in Holland many years ago investigating advanced technology MRI scanners.  Beautiful country . . . rich in history . . . and, GREAT food.  I imagine Denmark, Sweden, and Norway are equally spectacular.

 

Thanks.

 

 

Hmmm. Sounds like something on the computer side. I'll defer to the experts.

I'm currently using FSX "Real" Weather and REX 4 Themes.  I have OPUS Live Loaded but not in ops yet.

 

Do you use FSUIPC to smooth the winds? Default FSX weather loader can change wind speed and direction very hard.

 

 

I imagine Denmark, Sweden, and Norway are equally spectacular.

 

Danmark is kinda boring (except maybe Copenhagen...definitely not Jylland, where my family/friends live), but I probably just think that because I also have family in Norway.  You really can't beat the natural beauty there.  Sweden was a really cool place, too.

 

As far as your issue goes, though, my bet is still weather.  How did it go when you turned weather off?

 

Danmark is kinda boring (except maybe Copenhagen...definitely not Jylland, where my family/friends live), but I probably just think that because I also have family in Norway.  You really can't beat the natural beauty there.  Sweden was a really cool place, too.

 

 

 

Kyle

 

It is Denmark. Caught you on one. Do you have any idea where the &NBSP is coming from? And &amp just showed up.

 

Michael Cubine

 

 

It is Denmark. Caught you on one.

 

haha - nej.  Det er faktisk Danmark på Dansk.  Norge er 'Norway' på Norsk, og Sverige er 'Sweden' på Svensk.

 

...just a habit of mine since Danmark and Denmark are so close when typed.

Det var da en tråd, der tog en drejning.

 

But try to disable the turbulence effects in FSUIPC and FSX Real Weather. The PMDGs have a problem with the way turbulence is simulated.

 

 

 

Another option might be to use HifiSim ASN for weather. Since I changed to ASN I have never had the S-turn problem. And I have had plenty of turbulence.

 

Lasse

Guys . . . here are my findings.

 

1.  I initiated a short flight this afternoon without using the FS "Real Weather" setting . . . aircraft stable.  I re-engaged "Real Weather" and shortly after the uncommanded rolls commenced.  I disabled the "Turbulence" option and aircraft settled down.  I re-engaged the "Turbulence" option and flight remained fine through landing.

 

2.  I initiated another flight . . . a little longer in duration . . . 220 miles.  I began with FS "Real Weather" engaged and "Turbulence" option active.  About 10 - 15 minutes into the flight, the uncommanded rolls began again.  I disabled the "Turbulence" option and the aircraft settled down for the remainder of the trip . . . although it did drift 1.5 to the left of LNAV track.  That puzzled me somewhat since the crosswinds were at around 85 knots at about 330 degrees off the nose of aircraft heading.  That kind of wind should have pushed me to the right of LNAV track. 

 

I think it is under control with the PMDG aircraft and thank you for the guidance!  It is interesting that the Level D 767, and the Captain Sim 757 & 767 operate fine with the "Turbulence" option selected.  I may spend some time doing a comparative review of the aircraft.config files and see if anything stands out.  A few days ago, I had some serious turbulence while flying the 757 . . . the aircraft handled it like a trooper and at cruise it was smooth flying.

 

Again, many thanks! 

 

 

Det var da en tråd, der tog en drejning.

 

haha - oops

 

 

 

Since I changed to ASN I have never had the S-turn problem. And I have had plenty of turbulence.

 

Agreed.  Great implementation of turbulence in ASN with no S-turns.

Disable turbulence effect in FSX.