Hi all,

I’m seeing pitch oscillations (“bobbing”) during step climbs in the PMDG 777. For example, climbing from FL300 to FL320, it climbs normally at first, but in the final stage it starts pitching up and down very erratically while trying to reach the selected altitude. It does eventually hold altitude, but the last part of the climb is quite unstable, even though VNAV shows it as achievable.

The aircraft is around 300T GW, with OPT ALT is above the step climb alt. I’m using VNAV/LNAV with economic speed, realistic turbulence enabled, and I’ve already turned off AI auto-trim assistance.

 

Thanks!

Thanadee

You don’t say what sim you’re using. Please advise and I’ll move this post if necessary.

Hello,

I'm using MSFS 2024 with the PMDG 773ER.

 

Regards, 

Thanadee

Moved to FS2024 forum.

The PMDG 777 does have a tendency to "bounce" at times when making small adjustments. I saw it recently when it reacted to getting to 6100 feet when the cruise altitude (in a circuit) was 6000 feet. It adjusted by "bouncing" up and down multiple times, rather than smoothly pitching over slightly to compensate for the altitude correction. It is actually something that I noticed at times in P3Dv4 with the 777, and even worse in the 747. I would love to see a fix for that, because "bouncing" is totally unrealistic.

Edited April 14Apr 14 by Christopher Low

I’ve had it happen in cruise sometimes, really messes up the autocruise/ time acceleration.

Other times it’s perfectly fine though.

4 hours ago, Christopher Low said:

 It is actually something that I noticed at times in P3Dv4 with the 777, and even worse in the 747. I would love to see a fix for that, because "bouncing" is totally unrealistic.

P3D v4 is too far back for me to remember. I have had nothing like that with V5 and the 747.

I do not own the Triple Seven in MSFS 2024, but I am surprised that this behaviour still exists. I remember that the P3D version showed this behaviour.

38 minutes ago, Holger0815 said:

I do not own the Triple Seven in MSFS 2024, but I am surprised that this behaviour still exists. I remember that the P3D version showed this behaviour.

They have refused to address the issue in P3D, MSFS2020, and now in MSFS2024. Unfortunately, the same bugs persist, and they refuse to acknowledge them. Just copying and pasting the same broken items won't solve anything. There have been numerous problems with the product's quality and quality control. So much for their claim of "study level." 

PMDG reccomends turning turbulence off, or since you're in 2024 -- to low. They say it isn't modeled accurately. 

Yeah, they said this for 2020 also. And yet, the PMDGs are the only planes having problems with the turbulences in 2020 and 2024. For some devs out there, it's always the users and/or any other softwares fault.

To be fair, "realistic" turbulence in 2020 and 2024 definitely isn't.  I run turb on low and even then I see occasionally unrealistic air movements, though 2024 seems a bit better about this.  But "realistic" is way overdone in both sims.

But also, PMDG is known for accepting flaws in their flight model and auto flight behavior as LRBS says.  They have a tendency to then try and gaslight their users into believing that it's a "realistic quirk" - until maybe they finally fix it a few years later and then tout themselves as the best dev in existence for being able to solve this suddenly egregious problem that they've told you was fine for a long time 😉.

TL;DR - it's probably a little of both.  You can't fix the PMDG issues, but you can certainly try turning your turbulence down.

P3D did not have turbulence, so the oscilation problem may not be related to turbulence. 

1 hour ago, Holger0815 said:

P3D did not have turbulence, so the oscilation problem may not be related to turbulence. 

Pretty sure it did/does have turbulence?

From the documentation:

"You can set turbulence in wind layers or cloud layers, or in both. If you have wind and clouds set at the same altitude and you set turbulence in both layers, the turbulence you define for the wind layer will take precedence." 

6 hours ago, Watsi said:

Yeah, they said this for 2020 also. And yet, the PMDGs are the only planes having problems with the turbulences in 2020 and 2024. For some devs out there, it's always the users and/or any other softwares fault.

100% I definitely wasn't trying to stick up for PMDG and blame MSFS for their lack of sophistication on turbulence because, as you mention -- other addon planes don't suffer from the same issues PMDG planes do. It actually blows my mind that the same bugs are still present in MSFS2024 that were in P3D and even beyond.