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Old July 5th 09, 12:16 AM posted to rec.aviation.piloting
Bertie the Bunyip[_24_]
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Default Feathering an engine

Ron Garret wrote in news:rNOSPAMon-
:

In article ,
"Tim" wrote:

The point was how much do you gain by stopping a fixed pitch prop, as
opposed to letting it wind mill.


A lot.

You can actually do this experiment in a plane with a variable-pitch
prop. Idle the engine, and play with the prop control. I did this
years ago in a 182RG during dead stick landing drills. The difference
in glide performance between the two extreme prop settings was quite
dramatic, almost like having an extra set of very fast acting flaps.

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.

rg


Actualy, a pro that is spinning freely, with no compression, as in one that
is attached to a snapped crank, will cause more drag than one which is
driving all the internal bits in most cases.



Bertie