Sorry, I don't care who he is, I care what he writes (and I read it
carefully).

He does make valuable points - a tail chute is not a stupid idea. His
comment on wing momentum is very good (and I don't think that people are
well aware enough of that), and I completely agree on the fact that if a
60:1 performance is breathtaking on a long glide, 60:1 performance in a
vertical dive coming out of a spin is life-taking.

What I disagree with is the underlying tune of the the disaster(s) being
designed into the ship :

"But I think one can legitimately ask if there was something inherent in the
design of the sailplane that led its occupants into a situation from which
there was no escape. My thesis is, there was."

Now if today somebody wants 60:1, he will have to go for 26m, and the
structure of these ships cannot be built otherwise - at leat not today. Even
the newest development, the Eta, will bite during the recovery from a spiral
dive as it has been shown (on purpose - those guys have some balls... and
parachutes). With such a ship, some situations are extremely dangerous
(situations which would be rather fun in 15m), and if you want to fly such a
ship, you better start to think first.

What I also think being pure speculations is the stiffness of the ailerons
due to flexing (and in this situation, you don't loose time fiddling with
ailerons anyway), and when and how the airbrakes have been deployed. There
is a chance that the pilot pulled the airbrakes before reaching vne and
pulled to hard, and there is a chance that he pulled them after having
exceeded vne and tried to pull up (and at a certain point beyond the v-n
diagramm, any glider will brake up) - we will never know at which speed and
at how many g's the wings came off. In this light, his comment

"What the AFM didn't say of course was, "if you exceed the maximum permitted
speed and open
the brakes be prepared to have the wings come off."

is plain stupid.

However, his last paragraph is very good.
--
Bert Willing

ASW20 "TW"


"Papa3" a écrit dans le message de news:
...


Bert Willing wrote:
It sounds like written by somebody who is astonished that a 26m ship
might
handle in some situations differently than a 15m ship, and that if there
is
any accident evolving of this, the designer of the ship should be
responsible (and not improper pilot reactions).

Bert Willing

ASW20 "TW"


Bert,

That's an odd comment. When someone like Stan Hall writes about
stability, control, and structures, I listen. Carefully.

I think the bottom line in his analysis is very clear. Open Class
performance comes with risks that need to be completely understood AND
there are flight regimes where the margin between recovery and disaster
is very, very thin.

Erik Mann
LS8-18 "P3"