Duct Fan wrote:

Looks like Bill Freeman may be correct.

--- In canard-aviators@y..., "Verne Simon" <res09zd0@v...> wrote:

----- Original Message -----
From: Barry Schiff

A friend sent this. Gary has dedicated his life to aerodynamics. He
invented the Wheeler Vortex

  generator, and the "Gurney" wing on race cars. These are his views
on the crashed Airbus.)

  Howdy,

  Re: the New York 11-12-2001 Airbus crash.

  I found this photo of the vertical stabilizer's failed composite
attachment
  blades, or webs. The bolts that attached the composite vertical
stabilizer to
  the fuselage, remain properly attached.  Clearly, the failure is a
  delamination of the composite vertical tail, above the points of
attachment
  to the fuselage.

  There are reasons (despite the weight savings) why Douglas Aircraft
and
  Boeing have never used composites this way -- and you're looking at
one.

  As the delamination of the composite progressed, the entire 37-ft.
tall
  vertical tail would have fluttered briefly & violently.  That would
explain
  why both engines were literally shaken off the airplane.  (This is
  particularly remarkable, because unlike Douglas and Boeing, Airbus
has
  bragged of purposely designing their engine mounting pylons to keep
the
  engines in place no matter what!)  One wing tip was found several
blocks away
  from the main wreckage.

  BTW, you'll be hearing a lot about an encounter with wake
turbulence.

  That is a red herring.  Wake turbulence can make it difficult --
maybe even
  impossible to control the airplane -- but no amount of wake
turbulence can
  remove the vertical tail at such low flight speeds unless there is a
  preexisting structural fault.

  What is flutter?  This morning, I got an email from a friend who is
the
  Director of Structural Engineering of a major American aircraft
maker.

  He described a chilling picture:   "Flutter modes often have an
explosively
  quick onset, rising from nothing to catastrophic in the blink of an
eye.
  Furthermore, the shaking can happen so fast that, despite the large
(huge)
  deflections involved, an observer on the ground might not see it.
It's just a
  blur.

  "The people in the back of the airplane would have been shaken
senseless and
  worse as the seats tore loose and everything was homogenized back
there; but
  it was all over a few seconds later."

  The design weakness can and will be fixed on other Airbuses.  If
not, there
  are plenty of nice Boeing jetliners mothballed in the Mojave Desert,
that can
  trade places with the Airbuses.  In the meantime, I'm not riding
Airbus.

 
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