Wing De-Icing Question

On Feb 16, 7:51*pm, VOR-DME wrote:
This discussion is rapidly running in the wrong direction.
While I do not share the admonition of some that it is "taboo" to speculate
about causes of an airplane accident before all of the factual information is
in, it is certainly unhelpful and disrespectful to start crying "pilot error"
and lamenting all of the things they should or should not have done, before any
of the salient facts of the scenario are in place. Similarly, it is reckless to
start decrying insufficiencies in any of the aircraft's systems or their use
without a solid factual basis for these assumptions.

It may be useful to discuss airframe icing and tailplane icing, and it is
perhaps *pertinent to speculate about its role in the current case, but to go
much further can only foster misunderstanding and misinformation. Have instead
some respect for the people who lost their lives, and for their families, as
well as for the flight crew who just may have known a thing or two about how to
fly their airplane. . .

Keep in mind that this is a pilot's discussion group. Some of us fly
in conditions similar to that in existence for the Buffalo crash. As
with all such events, there are things to be learned. I subscribe to
"learn from your mistakes, but it's better to learn from the mistakes
of others because you won't live long enough to make all the mistakes
yourself."

As each new bit of information about this event comes available, I try
to imagine myself in the same situation and try to figure out what was
going on.

I had previously been shown the NASA video on tailplane icing while
attending a Flight Safety Inc recurrent training course for the
Citation. Previously, I'd never heard of this before. Hearing some
of the preliminary information about the Buffalo event reminded me of
this video so I found it on-line and watched it again and I'm glad I
did because I was remembering some of it incorrectly.

Anyway, more recent information is a bit inconsistent with the
"tailplane icing" theory, namely, that the flight data recorder says
that both the stick shaker and stick pusher were activated. This are
activated (at least in the Citation) by angle of attack sensors which
are electrically anti-iced. I can't see how this could happen in the
tailplane ice induced stall scenario.

The information about excessive bank angle would also be inconsistent
with this, except that if it really were tailplane stall due to ice,
the yoke might have been yanked forward and out of the hands of the
pilot. Attempting to pull it back might have resulted in inadvertent
aileron deflection, causing the roll.

K l e i n