I was thinking of the throttle servo mainly.
on one of the threads a person with a giant scale had a throttle servo go full throttle on him. Lucky it was on a stand and he was not close
That was me....and it was scary.........It was a loose plug cap on a DA-50. Fixing the plug cap (adding a small hose clamp around it) resolved the issue. I have doubts a ferrite ring would have helped but in the end it was not needed....fixing the issue with the plug cap resolved the bigger issue....unfortunately it cost me a severely damaged plane to figure it out....
CB