l W wrote:>

> Here's an excellent example. I've seen people describe their
> reasoning
> for going rotary. Often I would hear: "It only has three moving
> parts,
> therefore it's safer". I suspect that 80% of you believed that. That
> is a
> gross error in perspective. No maybe, it's a huge distortion. It's
> a
> wonderful theory, it has a component of truth in it, but totally
> fails
> the tests for significance. If a logical theory is not significant,
> you
> dump the theory.
--------------------------------------------------------

Have stayed out of this as long as I can, but it seems strange to me as a
gas turbine designer of 33 years that Al would make this comment without
at least backing his words up a bit. I find it hard to believe that a
modern technology reciprocating engine that is snapping pistons back and
forth at 5000 rpm with cams and valves is anywhere as safe as a rotary.
If the modern tech recip requires a PSRU and the addition of water
cooling those things components are canceling.
Having participated in many FEMA studies over the years ,I find some of
Al's comments a bit strange. His heart may be in the right place to try
to help us Rotorheads, but am not convinced he is helping us sort out
what is important to take care of to eliminate failures.

Will never forget my intro to rotary's. A friend at work raced a rotary
powered car. He took the car to the Daytona 24 hour without detuning and
after returning he left the car on the trailer and went to miami next
week without any additional work. This was a totally different story from
the recip guys. They installed very expensive forged lightweight parts
and deturned the engine. After the race they replaced all of them before
the next event. Does that say something to you about the robustness of
the rotary? Does to me and is one of the big reasons I am flying one
today.

Bernie Kerr, 40 hours on 13B powered RV9A,

PS. Do I feel as comfortable with the 9A as I did when I sold the
Lycoming powered 6A ? Not Yet!
>

Hi Bernie,

I've also done FMEA studies for electronic designs. Al and I have been friends since circa 1998, before we both were flying. But I have to say Al is just plain wrong on this one. The rotary with its few robust moving parts and soft failure modes - there is no doubt it is fundamentally safer than any piston engine. All the other external systems are basically similiar or common between a Subaru and a Mazda, and that is where most of the failures are because that is where the custom design takes place in each installation. If you did a detailed analysis of all the internal parts of a Subaru (engine only) and related stresses, then compared that with the a similar analysis for a rotary engine, ignoring everything else that is basically common anyway, guess what? There is no way that crazy Rube Goldberg piston contraption could ever come out ahead.

Very comfortable with my Rotary EZ (almost too comfortable!)

Perry