One second of lack of focus cost me 19 stitches. It is difficult, but stay focused around a running engine. And if that is hard, imagine that it is a table saw blade spinning on the front. Not many of us would want to stick our hands near something like that, but the results can be the same with a prop. I saw a guy hand a radio over the prop to another at the back of the plane yesterday. I just cringed waiting for him to get hit somewhere between hand and elbow. Luckily it didn't happen, but he never even thought about what he was doing. focus, focus, focus