A320NX FBW Experimental Latest (09/19/2021 - 7de8f12) - Not allowing changing sim rate?

The changes have been pushed to development version. I hope this improves situation for you.

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Thanks for the heads up…
My experience with the experimental at higher sim rate is mixed.
Yesterday in stable flight, normal fps, at 2x rate the AP went berserk and the plane spiralled without any possibilty to recover control until crash or overstress. Hapened to me twice.
Two days ago, I tried to reduce render scale to 30, to reach 50 fps. Increased rate to 4x and also inmediate spiral and all on board dead…
Also this protection gives problems when loading a saved flight record from the FlightControlReplay app. The rate starts changing by itself between 0.25x and 16x when opening a saved reply file and putting the aircraft under pilot control.
You said it would be possible to disable the sim rate protection via config file. How can this be done?
Thanks again for your efforts and patience.

Thanks so mush AGuther
Is there an option to shut down the mechanism completely?

Yes, sorry to be the bearer of bad news, but the current system of increased rate is absolutely unstable for me. I have tried today on my older computer (a lower end machine) and at 2x, without any reason, the plane can go out of control and it is unrecoverable.
With the the experimental version, one week ago, I never faced this. Even when I tried 4x, the plane started wobbling sometimes, but there was enough time to decrease sim rate and it stabilized flight.
Now, once it starts swinging, AP disconnects immediately at it cannot be stabilized until it crashes.

Added problem: now, attempting to load a saved .FLT flight results in instant CTD 100% of the times. Some days ago, loading saved flights worked fine for me; I could reprogam the MCDU on flight and resume my trip without problems (besides in-game ATC going either mute or yelling nonsense). I am not sure if this is caused by WU6 hotfix, or by the FBW A320 recent experimental and development versions, but it may become a deal breaker for me… :frowning:

Sorry to hear that, we will continue to improve this aspect. How many fps do you have?

I think the CTD is unrelated to the changes in that area.

The mechanism to disable the reduction completely is to add the following parameter to a file ModelConfiguration.ini in work folder:

[autopilot]
simulation_rate_reduction_enabled=false

Thanks for the reply.
In both my computers the fps were in the 20 - 30 range when the plane goes crazy. One has high-end graphics settings and the other low-end visuals, to get the minimum fps.
In both the AP can go crazy without reason, and once disengaged the plane is out of control until its demise.
Before the last changes, 2x was perfect on both computers, on the fastest one I could sustain 4x under certain conditions (and no plane crash was ever caused by setting 4x).
I will try your config file tip…

@AGuther sorry to be such a pain in the a***, but I do not have any “ModelConfiguration.ini” in my C: or D: drives (main drive and MSFS drive). If I create one, where should it go? i.e. what do you consider as the "work folder? The D:\Program Files\Microsoft Flight Simulator 2020\Community\flybywire-aircraft-a320-neo ? (in my setup). Or a sub-folder of that?

EDIT: I think I found the “Work” folder, in C:\Users\MYUSER\AppData\Local\Packages\Microsoft.FlightSimulator_8wekyb3d8bbwe\LocalState\packages\flybywire-aircraft-a320-neo\work
But I added the ModelConfiguration.ini there with your suggested contents and it seems to do nothing :frowning:

That will not help for oscillations. They are caused by low sample rate which is an issue for the roll law.

I’m working on a further improvement so that we are hopefully getting rid of the oscillations. I doubt it will ensure for all cases that anything works in all cases with high sim rate, but at least it should work for cruise. fingers crossed

I’ve pushed a potential fix to experimental version. Please try it out and report back if it helps (wait for another ~ 30 minutes after this post to ensure you get the version with the fix).

Thanks I have just downloaded and will try it NOW.
Pity I only have here my older low end computer but I will report anyway

Then you’re a perfect test candidate…

I did a first flight Barcelona to Firenze, and just perfect, using sim rate 2x above FL10. My fps are 20 to 29, with graphics at 1080p low/med.
My first completed flight without events in almost one week!
Now I am on the return trip, at cruise, and so far so good. I can see now that from time to time the plane starts wobbling, but the AP immediately corrects it. With the earlier version this would have implied a plane crash.
What does not seem to be working is the config file to disable this protection. I am still limited to 2x, which is not a catastrophe but I would appreciate running some flight legs at 4x, at least with my other much newer computer.
Anyway, a big THANK YOU for sorting this out

I confirm, second flight completed just perfect.
For test, I kept speed 2x until almost glideslope capture :slight_smile:

The option that I gave you disable the reduction but the not the Limitation based on your framerate when trying to increase it. So it works as intended.

Thank you for the info that it now works better.

Just as a side note:
If you look at our discord, I posted a video of an Autoland in 4x some time ago…that works when you have enough performance.

I found this thread while looking for a solution to this bug. Given that it is not a bug, but a feature, I would like to cast my vote on the side of not continuing this “feature”. It certainly would be a deal breaker for me, and many others, for what I would assume are obvious reasons.
Many thanks for responding and letting us know what is going on. Back to the 9-17 dev version for me. Autoland works, and you can increase the sim rate as you see fit.

Thanks again.
I will try 4x when I am at my “good” computer after the weekend, but so far I am very happy with your solution…
Very smooth AP at 2x even with average frame rate and so far no more CTD after take off… fingers crossed

You can disable the reduction and even the limitation now. But be warned, it may get unstable. If you accept this do it otherwise respect the limits.

How to disable the feature? Via the config file? Which syntax?
Thanks again

This parameter is again in ModelConfiguration.ini:

[autopilot]
limit_simulation_rate_by_performance = false

Use it at your own risk.