Humm, I recall that accident as I had exchanged e mails with Parkman – he was the guru of converting auto CPUs to work in aircraft.  But, while apparently a whiz at the electronic end of things – less so on the mechanical side.

 

As I recall the accident which took his life, he had set his prop (adjustable) to give him the maximum rpm which of course turned out to be the minimum prop pitch (less load on the engine more rpm).  This reduced the thrust available because with the almost flat spinning prop blades the Dv imparted to the air was much smaller than it would have been with less rpm but more pitch.  As a results, his long EZ (I believe) accelerated sufficient to gain airspeed to lift off in ground effect – but never enough to climb to altitude – Steve unfortunately impacted a tall catus plant and was killed.

 

So maximum engine rpm does not of itself indicate maximum thrust.  A balance between generating power (engine rpm) and transferring that energy to accelerating the air is what we are looking for.  Too little rpm (power) and thrust goes down – too much rpm but too little Dv and thrust goes down.  Like just about everything in this hobby, its about balancing conflicting parameters.

 

That’s my take on it.