On May 7, 8:22*am, Mike Ash wrote:
In article ,
*Ron Garret wrote:

There's also the conservation of energy argument. *If the engine is
turning, the energy to overcome friction and compression has to come
from somewhere.

I don't think this works. In the non-spinning case, you're dissipating
all that energy into the air, and there's no real limit as to how much
that could be. Now, it would seem that the conservation-of-energy
argument gets you the right answer, but IMO not for the right reasons.

--
Mike Ash
Radio Free Earth
Broadcasting from our climate-controlled studios deep inside the Moon

I couldn't see, from those charts, that the spinning prop
developed a LOT more drag, like the flat plate some here claimed it
would be. A flat plate the diameter of the prop disc would be about
four times the flat-plate equivalent of the aircraft's profile, I
think, and would steepen the glide to some awesome angle.
I'm going to have to go up and do it again. Many years ago I
stopped the prop on a 150 and found that the glide was a hair steeper
for a given airspeed. The prop stopped, reluctantly, near the stall,
and diving the airplane to Vne would not restart it.
How many others here have actually tried it, besides me?

Dan