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(Low - quality of life, workflow optimization, rare enough to not impact production, etc…
High - critical but workarounds are available, important feature not working as expected, frequent enough to impact production
Blocker - prevents from working on the project, prevents from releasing the product)
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Bug description: A bug seems to have been introduced in SU4 beta that causes the rotor rpm to shoot up towards 140 - 160% RPM. It does not happen on every landing but frequently. Surprisingly it has so far happened every time I land next to a river. I am not able to identify the cause.
@FlyingRaccoon Hey Sylvain, are you already aware of this phenomenon in SU4 beta or should I do a demonstration as I usually do?
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Thank you for the link. @FlyingRaccoon There are a few aspects in that existing report that I would like to put into context.
The report mentiones the rpm shooting up as a consequence of the yaw moment on touchdown. I think this might be the opposite way around. It would seam more plausible to me that the yaw moment is caused by the rpm change.
The report continues by putting this into connection with rotor inertia and spool down timing. The shutdown time of the h125 is fully unrelated to this issue in my opinion. In my own project there has been no negative change in shutdown timing and I think I can speak for most heli devs when saying that we would be happy if nothing is changed in that regard since most of us have probably spent a lot of time to get these timings right. The issue on the h125 described by the user can be solved by tweaking the existing flight model parameters, there is no additional bug fix required.
EDIT: I was able to narrow it down to the wake turbulence setting being activated. I had been in the beta for quite a few days, however the rpm issue only appeared within the last two days. So I went back in my head and thought what did I change, the wake turbulence being that single thing I changed in the settings. Since I did not have this setting active in SU3 it would need to be confirmed if it was already present back then, but concluding from the other reports it seems to be new in SU4.
Good to hear from you.
Yes, the issue is still present for me. The key is that you do a sim restart after turning wake turbulence on. The bug wont appear immediately after changing the setting.
Somehow, I still cannot replicate the issue on my computer, but other people at Asobo witnessed it and we have a lead on what could cause this.
A fix is in the pipes and should be available with version 1.6.29.0.
When it’s available, please check again and let us know if this solves the problem.
Hey @FlyingRaccoon
I just tested the newest beta, there seems to be an improvement in such a sense that the RPM does not rise as high as before (now roughly 120 instead of 150), but the bug itself remains. Not every landing seems to be effected the same way which was visible in the demonstration I prepared.
Ok, we’ll keep investigating.
Can you confirm you have the newly introduced Vortex Ring State Protection assistance disabled?
If it was enabled, can you check if toggling this assistance makes any difference?
I think it appeared for me with SU4, the bug report made in the user forum would support that as well. Unfortunately I do not have the time at the moment to unistall the beta to test this. @d41k4n maybe you can help to verify this?
Yes, but you mentioned this appeared after you enabled wake turbulence.
We also think this is related to this option. But since it hasn’t changed since SU3, it would be interesting to know if the issue was in fact already present in SU3, or if another change in SU4 played a role.
It’s likely the fix will have to be postponed to SU5, and the wake turbulence option will have to be disabled by players in SU4 in the meantime.
Yes that is correct, when I was still in SU3 a friend told me about this bug that he mentioned as new in SU4 beta. When switching to the beta I did not experience it at first due to the wake turbulence being off. However I am pretty sure that the friend of mine has not changed this setting and had it permanently on. I will ask him again to confirm that this information is accurate.
EDIT: So I was able to confirm that he indeed had wake turbulence always active in the past.
A fix candidate is introduced in version SU4 beta 1.6.31.0, which should be available now.
There was an issue with Wake Turbulences / CFD interaction that could cause a wake turbulence burst.
Can you let us know if you still witness the issue with that build?
During tests with the HPG H145 on 1.6.31.0 I had one single occasion where the rotor RPM shot up right after touch-down (on a perfectly flat surface, rooftop helipad). Granted, it wasn’t as bad as in prior versions but still felt abnormal. Maybe the issue is not entirely gone but at least it’s not as common as before. We may have to live with it
