Engines running crew changes were often done on the RAF C130K fleet. The Air Loadmaster (ALM) would exit first from the crew entrance door and screen the engines off with his very long intercomm lead providing a 'fence' to remind crews not to turn into the propeller arcs. As far as I know without any incidents occurring. The ALM would renter the aircraft last.
I remember, around about 1970, a Britannia aircraft, on engine start at night, one of the start up crew walked in to a propeller with fatal results. (It was necessary for a start crew member to ensure that the hold the propeller during engine start to ensure that it was not turning in the wrong direction at the beginning of the start sequence, so they would always be very close to the propellers). I think that the Board of Inquiry concluded that the bright apron lighting caused the propeller to appear to be stationary due to the stroboscopic effect.
From Wikipedia:
The
stroboscopic effect is a visual
phenomenon caused by
aliasing that occurs when continuous motion is represented by a series of short or instantaneous samples. It occurs when the view of a moving object is represented by a series of short samples as distinct from a continuous view, and the moving object is in rotational or other cyclic motion at a rate close to the
sampling rate. It also accounts for the "
wagon-wheel effect", so-called because in video, spoked wheels on horse-drawn wagons sometimes appear to be turning backwards.