Hey! I know a guy that got hit in the head by an airplane prop and yes, it almost killed him. And no, he wasn't any more stupid or careless than you or I, he got distracted in a dangerous environment. A fast moving prop is invisible, and airports are usually very noisy, and once you get used to that constant din, noise is no longer a danger sign. I work at the airport now and you wouldn't believe the dangerous things we see people do - we joke that security screening somehow sucks their brains out as they walk through the metal detector. Of course, that is not true, but in an unfamiliar environment ( like perhaps a busy tarmac of an airport) , people behave very strangely. If you think that no-one is allowed on the tarmac of an airport, you haven't flown much lately. More and more mainline (big airplane) flights are getting replaced by RJ flights (little airplane) and these smaller aircraft are often boarded via stairs from the tarmac. Sometimes it is like herding cats trying to keep the people in a safe area so that they don't wander off and get hit in the head by a prop.