I've had a rather large RC helicopter crap itself to death at high RPM and launch a blade at me that hit me in the triangle. The repairs cost about $240 but the blade that hit me didn't even snag a thread on my field jacket. That's an 18" wooden blade at max speed. I was very close when that happened.
Did you go to the link at my tag line? The head of Air Force research sent me a thank you note back in 2006 when I brought this attack vector to his attention. Just sayin’.
That was after I first went to the Secret Service and they put me in a holding cell before turning me loose with the suggestion that I “get my meds checked.” Funny how often I hear that! That was when I decided the Air Force would be more receptive to my concerns.