Hi Thomas. Thanks for the answer. I was maybe little too emotional, which is probably what you are when you crash your heli
Damage is not tragic, it's just lots of work now.

One thing I changed in the 570 kind of recently, was mounting a different tail pulley, which is supposed to speed up the tail. SAB recommends that if you're running lower than 2600 RPM, and I was flying at 2400. Could this be a reason? Bearings are new.

The after-flight rescue test sounds great. I was always testing the rescue before spinning up. I will definitely add post flight rescue check to my procedure. I will also try to record vibrations next time I'm flying with Kraken, so will probably come back with this one.

I think it is not Spirit unit at fault, because I have 2 and both behave same. Having problem in both, I immediately thought about firmware - I did upgrade recently. I even wanted to downgrade, but I didn't find any way to obtain older versions. But if you say with confidence that nothing was changed in rescue in newer versions, then I just use latest. But for future, are older versions available anywhere?

Great to hear it works fine on TRex. I think Kraken should be fine with static, I think the way boom is connected it should allow some electricity to flow. But not really sure. Could such thing cause FBL to work but have rescue problems?

With higher tail RPM vibrations are higher too. They can be significantly higher in amplitude but also higher frequency is unwanted too.
So yes, the tail could be reason if there is something unbalanced. If rotor head is unbalanced then it is not nearly problem at all, because these vibrations are low frequency. So even if you can feel it by hand a lot they will not cause any troubles. But vibrations that are resonant or are of high frequency are big issue.
Static electricity could cause rather a bigger problems but precision of the rescue should be same. But in theory it could affect other things which in turn could affect unit generally. And this could affect Rescue.
For example GeoLink affected by static discharges could transfer them to the Spirit unit and this could cause another problems.

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Spirit System developer

Hi, sorry for late reply. Tomas already answered on the post above. I hope you manage to get it fixed.