Many thanks for the various explanations re mast bumping etc.. I asked because many years ago, before I was a pilot, I was given an R22 ride as a birthday present. The pilot let me have a bit of a waggle on the controls etc, then did a simulated engine-out auto rotate to a landing. This went well, but knowing what I know now, I would have said "no thanks" to that particular part of the demonstration !!
With all the mast bumping incidents, is it not well overdue for a redesign - strengthening the mast and some sort of soft ring within the teeter head to prevent mast damage from bumping?