[steve86]

What I can’t remember is whether the airspeed of the aircraft is added to the rotational speed of the prop tip in analyzing that. Tip speed below supersonic is desirable, of course, because of efficiency reasons, and these were constant speed units. Have to research...

[PSYCHO-FREEP]

Look for the effects of compression in this case. Jet engines compress the air they take in and then dump it back out the rear end. The effect is what we see. Wing tip vortexes also applies to propeller dynamics. I'm sure you know that a propeller is just another wing and the same principle applies.

I am a retired Alaska Bush pilot and have seen this happen first hand. Especially when I took off of some short lake, heavily loaded on floats, with air/moisture levels off the chart.