Air Bus 300 crash in NY now blamed on co-pilot's improper use of rudder

Peter Duniho wrote:

"Mike Rhodes" wrote in message
...
[...]
If the control inputs are controlled, as I believe Airbus is, then the
pilot cannot be blamed for over-controlling; unless the manufacturer
pointedly states not to do that.

The manual for my airplane (and most, I believe) says nothing about not
pulling too hard on the yoke when recovering from a dive in which the
airspeed exceeds Vne. Does that mean that the manufacturer would be to
blame if I caused the wings to fail by doing so?

I don't think so. I'm curious why it appears that you would.

The manual does likely say something about the definition of Vne, however.

- Andrew

On Tue, 26 Oct 2004 14:11:41 -0700, "Peter Duniho"
wrote:

"Mike Rhodes" wrote in message
.. .
[...]
If the control inputs are controlled, as I believe Airbus is, then the
pilot cannot be blamed for over-controlling; unless the manufacturer
pointedly states not to do that.

The manual for my airplane (and most, I believe) says nothing about not
pulling too hard on the yoke when recovering from a dive in which the
airspeed exceeds Vne. Does that mean that the manufacturer would be to
blame if I caused the wings to fail by doing so?

I don't think so. I'm curious why it appears that you would.

I'm guessing you're not really curious, for the general nature of you
reply was not one intended to encourage discussion. As for the
paragraph above I'm very surprised you think that makes any point at
all, other than my own. Because it is rhetorical...

--Mike

On Tue, 26 Oct 2004 at 20:52:36 in message
, Mike Rhodes
wrote:
I recall some question concerning a weakness in the design of the
rudder itself, in that the supports to the composite structure were
too few. Not too long after the accident, I saw it was explained on
TV that the manufacturer should have distributed the load over more
points for the sake of the composite material. The known and
understood weakness of composites, compared to metals, is their lesser
ability to handle bearing stress. So Airbus should've known better,
presumably.

The original pictures seemed to show clearly that the root attachments
failed at the attachment to the fuselage.

How easy in turbulence is it to develop a pilot induced yaw oscillation?
The fin might well withstand a full deflection but not a few reversals
that built up the maximum yaw oscillation. Fins and rudders are as big
as they are to deal with the engine out case at relatively low speed I
understand. Isn't one of the functions of a yaw damper to restrict and
damp a yaw oscillation?

Do the reports give any indication of the amount of yaw excursion that
took place?

--
David CL Francis

"David CL Francis" wrote in message
...
On Tue, 26 Oct 2004 at 20:52:36 in message
, Mike Rhodes
wrote:
I recall some question concerning a weakness in the design of the
rudder itself, in that the supports to the composite structure were
too few. Not too long after the accident, I saw it was explained on
TV that the manufacturer should have distributed the load over more
points for the sake of the composite material. The known and
understood weakness of composites, compared to metals, is their lesser
ability to handle bearing stress. So Airbus should've known better,
presumably.

The original pictures seemed to show clearly that the root attachments
failed at the attachment to the fuselage.

How easy in turbulence is it to develop a pilot induced yaw oscillation?
The fin might well withstand a full deflection but not a few reversals
that built up the maximum yaw oscillation. Fins and rudders are as big as
they are to deal with the engine out case at relatively low speed I
understand. Isn't one of the functions of a yaw damper to restrict and
damp a yaw oscillation?

Do the reports give any indication of the amount of yaw excursion that
took place?

--
David CL Francis

correct me if i am wrong but wasnt it the ntsb that a few years before
aa 587 critized a crew for not using full and complete control deflection
for another accident? i do not remember which one it was but shortly after
some of the airlines started going to those upset recovery courses. sounds
like the ntsb wants it both ways.

tony zambon
grumman 9941L

Could someone refresh my memory....
what is the definition of maneuvering speed again?

PS2727 wrote:

Could someone refresh my memory....
what is the definition of maneuvering speed again?

That you can fully deflect any control surface without structural
damage. However, this does *not* necessairily imply that you can waggle
from one extrem to the other! Actually, you can't do so with many airliners.

Stefan

Stefan wrote:

PS2727 wrote:

Could someone refresh my memory....
what is the definition of maneuvering speed again?

That you can fully deflect any control surface without structural
damage. However, this does *not* necessairily imply that you can waggle
from one extrem to the other! Actually, you can't do so with many
airliners.

I recently read an article on this subject; I just cannot recall where.
It's not just "waggle from one extreme to another" that's not covered by
Va, but also multiple inputs (ie. aeleron and rudder) in directions which
cause opposing (or concurring?) forces.

Anyone recall this article? Otherwise, I'll be digging through some
magazines tonight.

- Andrew

PS2727 wrote:
Could someone refresh my memory....
what is the definition of maneuvering speed again?

Design manouvering speed applies to pitch changes.

Before or after the loss of this aircraft?

PS2727 wrote:
Could someone refresh my memory....
what is the definition of maneuvering speed again?

As a multiengine instructor who has witnessed students applying full rudder in
the wrong direction after a simulated engine failure then quickly apply full
opposite rudder in the correct direction am I to understand that I was in
mortal danger from the tail breaking off? Seems that is a little late in
telling pilots how these things are designed....What next, we can't reverse
ailerons when landing in gusty conditions without breaking something there as
well?
Also, maybe someone can explain why the rudder limiter on this Airbus didn't
protect the structure when its sole purpose in life is to prevent damage to the
structure by limiting rudder movement at higher speeds.