Rotor brakes
Sanus
Agreed. You do not need a fully applied rotor brake or anything like it to cause a fire. There will be people on here who know / recollect far more than I do, but how about the Merlin Mk1 that went in the Sound of Raasay?
And, I have very personal experience of the results of cocking up the rotor brake action sequence. The result is unmistakeable.