[Woodworker88]

Originally Posted by EricH

My Aero Design team has a rule: NEVER stand in the same plane as the prop while the engine is a) running or b) about to be started. In front or behind is OK (or required, depending on who you are), but never to the side. Shield the plane of the props, and a little in front of and behind that plane, and you *should* pass inspection. By doing so, you also get a "ducted fan", where there is almost a funnel for air to pass through. These are just as good as unshielded props, if not better.

This is the same rule we have when working on props and jet turbines at the aerospace museum where I volunteer. All of our APUs (jet turbine powered generators) have distinct red lines painted on the enclosures to show the plane of the turbine blades.