Rich S. wrote:

Oh heck, Don. I was just trying to focus your problem solving skills on
where I thought the real problem was. It's not with the engine, of course -
besides, they're too hard to convince that leaving the airframe is the
proper thing to do.

Yeah, and the other thing is that you usually want them to stay firmly
attached.

I remember when I was building Esmeralda, I gave a bit of thought on how to
prevent the engine from departing the building in case I should ever toss a
prop blade. CG shift making the airframe unflyable, y'know.

Yep, I know of one fatal accident that started with the engine trying to
fly on its own.

I like the lathe tool idea, but there's others that might work. Since it's a
pusher, the prop would normally like to stay on something like a splined
shaft. You could have a snap-ring retainer that would resist it coming off
during an idling descent. To jettison, a rubbing block would push the snap
ring out of its groove and wind drag would yank the prop back and off the
shaft.

If it is a controllable pitch unit with separate blades, there must be a way
to retain the center section and just lose the blades. I think some of the
composite props have that happen unintentionally!

Okay, you just made me think of a way that would work for a controllable
pitch prop. Just make the retainer hub keyed to fit the prop, and when
you rotate the prop just right, it slings its blades.

Check list item: Make sure that the propellor control detent lock is
installed properly. WARNING: NEVER OPERATE THE PROPELLOR CONTROL IN
THE DETENT POSITION EXCEPT IN AN EMERGENCY REQUIRING THE BALLISTIC
CHUTE!!


It would seem that the most elegant solution lies in a prop shroud. No
moving parts, an increase in safety and possible efficiency improvement.

Rich S.

I finally figured out what you mean by a "prop shroud". Duh... Yeah
that could work.

Don W.