I was practicing right-aileron rolls, and at some point heli stayed rolling although I wasn't. I don't know if rudder or collective worked, because the everything happened in one second. But it looked like it got stuck rolling with right aileron, I think (but not sure) at a bit lower rate, then my earlier rolls were.

This heli already has some history of "similar" crashes last year where I never found a reason. But I rather excluded RX/TX and FBL parts. And I suspect a problem with one of the servos.

So big question is --
Could such thing happen, if one of aileron servos got stuck?

Wondering what FBL would do. Would it be more important for it to keep zero rotation rate if cyclic is release, or would it rather keep collective to match, or a but of both?

Hi,

I would check that your failsafe is set as you expect. It kind of sounds like signal was lost and everything stayed in the same position as you last left it. You may also want to double check range of your Tx - RX system.

Hope that helps.

Regards, Devin

No, it's not failsafe. It would be visible in logs, and my configuration would zero cyclic, turn off motor etc.
In the meantime I found it to really be a servo problem. Thanks anyway...