A good friend of mine had just completed his first home-built KJ-66 and was running it for the first time. A thrust measuring device was placed a few inches in front of the intake. The maximum applied thrust was recorded on each spool up, then the device needed to be zeroed for the next measurement. This was done by pushing a small button on the side of the scale. He misjudged the suction and had his hand sucked into the intake from ~5" away. He lost about 25% of the mass of his right index finger and the doctor really didn't have much to work with. The doctor managed keep the digit, although much thinner looking. The guy still has most of the movement but he is very lucky to have what's left. I have heard of much worse. See photo of the compressor wheel after engine tear down.

Kelly