Hello,

Not sure if it's a known issue with the latest version 737-800 4.00.007 (i wish it was but probably not because i could not find any info about it) but my PMDG is doing weird things recently.

It has huge issues staying stable, in my last 4 flights (never had that before, but haven't flown it in a while), at some points it started veering from left to right continuously. See 2 pics below taken a few seconds apart, the predictive white line just go from left to right continously so the plane continues to turn left-right-left-right). It's quite annoying, been flying those planes for years and never had that kind of problem that looks more like what you could get with some badly programmed default planes or when using time acceleration. This happened even on a 80NM straight line, suddenly it started moving left-right continuously.

 

Even once on ILS approach, after capturing the LOC it start going wildly from left to right to try to keep on the LOC and had to disconnect autopilot.

Really strange, hopefully someone has an idea (i have already tried without turbulance, without wake effects, low wind...) because for now i can't really make good use of my 2 cup of coffees 😁🤭😁

Thank you 🍺

Edited February 1Feb 1 by Bad_T
typos

I remember reading somewhere (i'll try to find it)an issue to do with the Yaw damper and turning it off and then on again....Or on if you hadn't already. might be worth a try.

Found it
737-800 Oscillating Yaw - PMDG Simulations

Edited February 1Feb 1 by BrianT

Thank you @BrianT, yeah that's probably what i'm experiencing, will try with yaw damper off even if it's obviously not a good solution (and maybe will create other issues, i guess if it should be on it's for some reason 😉). But maybe/hopefully with that thread they are investigating it.

I just want to say how useful those pics were in showing your problem.  People (including me) sometimes describe an issue that doesn't translate well into words, or could be a few different issues.  But pics like that show exactly what you're referring to, and we can even check out th wind you were experiencing at the time too 👍

So... it's definitely not your wind, at only 13 kts.  There was someone else recently with this problem and they did find that turning off the Yaw Damper resolved the issue.   So some people then started touting that "You need to turn off the Yaw Damper in this plane", which is absolutely not the solution!  ... because lot's of us have our Yaw Damper where it should be, and don't see these lateral oscillations.

Have you tried doing a Direct To to a forward waypoint, to see if that resolves the oscillations?

Also, are you running any other apps that influence weather or movement (RealTurb, Active Sky, FS Realistic, etc) ?

Edited February 1Feb 1 by JYW

Thank you for your input @JYW, yes, turning it off is obviously not a good solution. But i will try that because if it can at least prevent it from happening until a real fix is found it would at least improve a bit the situation.

I will do some more tests like 'direct to', but no i have very minimal addons, no activesky, no realturb, no fsrealistic, no other running programs.. no fancy complicated controllers (a simple joystick and xbox controller 🙃) so yeah it's really as close as a default simple setup as you could get.

🍺

Edited February 1Feb 1 by Bad_T

26 minutes ago, Bad_T said:

Thank you @BrianT, yeah that's probably what i'm experiencing, will try with yaw damper off even if it's obviously not a good solution (and maybe will create other issues, i guess if it should be on it's for some reason 😉). But maybe/hopefully with that thread they are investigating it.

I thought they were suggesting that it was "wired" the wrong way round and so on was off and viceversa. Whether anyone actually logged it with support I don't know

i always have yaw damper turned on, but i have only had this problem once, so it can't be wired 'back to front'. the time i had it i simply turned yaw damper off and back on.

1 hour ago, Bad_T said:

veering from left to right continuously

I had this issue with the 2024 version and removed RealTurb as a test. I haven't had the problem since, but I need to re-install RealTurb to complete the test.

I see you're not using RealTurb but the problem was almost identical...

Edited February 1Feb 1 by flyingscampi

7 hours ago, BrianT said:

I thought they were suggesting that it was "wired" the wrong way round and so on was off and viceversa.

No, it's definitely not mis-wired like that.

 

I would also check the flight stick or yoke for noise or unwanted movement?