Reminds me of the time I was messing with the engine on my dads 1/3 scale extra ( I forgot the model number of it).

It has a gas engine with a spring loaded starting system, to start it you turn the prop backwards a few turns and let it go, at the time I didnt know what I was doing so I turned the prop backwards and let go which was a big mistake! The prop spun around and got me right on my knuckle [:@]

Im pretty sure it cracked my knuckle bone (sorry, I dont know its technicle name ) because it hurt liek hell for a few weeks straight.