How i test the failsafe:
I left the engine running, switched off the transmitter and the engine stops immediately. As soon as I switch the transmitter back on, the motor starts again and I immediately have control of the helicopter again.

Thank you.

I created zoomin photo to show what is wrong.
There you can see that insulation of the antenna has wrinkles. Inside the anntena there is not only one wire but also shielding which is damaged always when bent like this is done.
Actually even SAB-made antenna holders are not designed well.
But I believe none of these are reason for crash. If signal is weak you will receive notice to your radio.

I think there are only two things that could possibly result to this crash:
a) Only one BEC cable is there - if BEC tester is passing with no issue or voltage alarm on the radio then it is OK. If there are two leads from BEC I recommend to use them.
b) During RPM change model can generate high electrostatic discharges if belt is loose. This can affect whole electronics. It is important to tighten the belt properly. However I believe with this model it is not too common.

Do you have logs by chance from your radio from the last flight?

I checked your settings and there is nothing wrong.

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Spirit System developer

Ah okay, I see. I'll keep an eye on the antennas in the future. Thank you.

The belt tension was definitely OK, as you can easily see from the belt tensioner on the RAW. It was parallel with the chassis.

Attached is the log of the flight from the DS12.

in your TX log you can clearly see the Spirit unit itself stopping transmitting telemetry at the moment of the rpm/bank change (vibrations, height) where the YGE is still transmitting values. the Rx voltage is climbing back to idle voltage (like in the start of the log before motor start) as if there is no more load on it: could be no load on servos anymore. seems as if the Spirit unit was dead at this moment, whereas the Rex3 still was working (thus no failsafe) as the YGE was still transmitting telemetry as expected via it. no idea if this is possible - but looks like.

can only be answered by Tomas of course - but there must have been some 'major event' at the moment of rpm/bank switch... could be static hit very well (as there is nothing on E2). the belt is cooling down very quickly in flight in winter even it looks fine before flight (i can see that too on the belt tensioner of my Diabolos very well - from mid to extreme within 1 minute of flight), air is much dryer... risk is really higher. but just a guess.

Ciao
Michael

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cheers
Michael

After checking your telemetry log I can confirm the unit stopped to respond completely.
Very likely it was not due to BEC voltage drop.
So the only real reason I can see is electrostatic discharge. To prevent from happening again I recommend to make conductive connection between tail boom and motor plate.
Also it is better to move away all cables that are near the belt. And all cables away from the grounding wire if it will be used.

The only thing that we can do from our side is to replace your unit so we can be certain it was not caused by the unit for whatever reason.

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Spirit System developer

I actually thought I had installed the cables away from the belt as best I could. I have to go up somewhere in the chassis to get to the fbl.

Thank you very much for the offer, I would very much like you to check or replace the spirit, yes.

From which parameter in the log can you tell that the spirit has stopped working? I would also like to have a look at it, but I don't really understand it yet.

Ahhh, I see. Now I see it. The moment I switch to bank 1, the recording stops.

The problem is not Bank but change of the RPM. It was exactly at the moment when it started to rise.

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Spirit System developer