Talking about ARF chOPPERS....
A newbie(well now he flies em well) in RC choppers fixed and brought his Raptor to the field...Everything was ok and while he was learning to hover(just5 above the ground)....on his 4-5 flight i think a blade got loose andflew straight to his toe and...he had a deep cut...He was taken to a clinic for stitches...
Just think about it...a spinning rotor's blade has infinite possiblities toget loose and go off in any direction but chose to go directly to his toe(thank GOD not anywhere above).

So guys (especially into choppers) make sure everything is tight and in place before and after every flight.

Cheers.