Hi Eric,

On Sun, 16 Oct 2005 20:48:49 -0700, Eric Greenwell
wrote:


Unless you are an engineer competent in composite design for crash
protection, I don't think you will learn anything about the design by
asking "where the Kevlar is".

Well... extremely light weight of a fuselage definitely makes me
wonder about crash protection - something Germany glider manufacturers
have a lot of experience with. I think there's a good cause why their
gliders are so heavy compared to the Diana 2.


I don't think any of the manufacturers test their gliders until they
flutter, because it is very dangerous.

Wilhelm Dirks did that with the DG-600...

Flutter testst are not performed inflight, but any aircraft needs to
perform static flutter tests before it's certified in Germany (a very
expensive thing to do - these tests are usually performed by Prfessor
Niedbal).

Even if the manufacturer the exact
flutter speed, he would be smart not to reveal that speed, for fear that
pilots would then use that speed as the "real" Vne.

The design maximum speed is Vne + 15 percent - this is what the glider
is designed for (and being flight-tested). Obviously this is the
proven speed where no flutter occurs... at least in a perfectly
maintained (prototype) glider.
I certainly wouldn't risk to fly that fast... do you think that
someone is so stupid to exceed Vne? I think most flutter cases happen
at speeds between Va and Vne due to unexpected turbulence.



Bye
Andreas