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

VOR-DME wrote:
This discussion is rapidly running in the wrong direction.
certainly unhelpful ... disrespectful ... reckless ... foster
misunderstanding and misinformation

Yeah I don't really disagree, but egads, this is Usenet and for that
sake r.a.p. The epitome of inconsequential. Who cares what's said here?

In article
,
says...


On Feb 15, 5:41*pm, Tman wrote:
Dudley Henriques wrote:
There's a very good chance the Boston crash might have been tailplane
icing.

Did you mean BUF or did I miss something in Boston?
T

Yes. I've been dealing with a Boston issue most of the day and my
senior moment quota kicked in. It was Buffalo.
DH


Oh thanks! Spent two hours on the NTSB database trying to figure what
Boston crash we were talking about! :-)

On Feb 16, 11:58*pm, VOR-DME wrote:
In article ,
says...



VOR-DME wrote:
This discussion is rapidly running in the wrong direction.
certainly unhelpful ... disrespectful *... reckless ... foster
misunderstanding and misinformation

Yeah I don't really disagree, but egads, this is Usenet and for that
sake r.a.p. *The epitome of inconsequential. *Who cares what's said here?

Well, a family member may care.
What if someone, desperate for information after losing a loved one, starts
hunting around usenet and finds a bunch of pilots saying that autopilots
are dangerous and their use is negligent?

There is a huge human cost in tragedy like this, and we shouldn't forget
it. As pilots, we accept the risk involved, but we must be sensitive to the
situation of general public who are not expected to accept this risk.

Besides that, just as a matter of intellectual honesty, we should give the
crew enough benefit of the doubt not to fall to the "it wouldn't have
happened to me. . ." fallacy - at least until all of the ifactual
information is in?

I fly IFR by hand in IMC for practice and recurrent training, but would not
subject trusting passengers to this risk. Instead I use the autopilot,
whose judicious use I consider to be one of the most important safety
devices in the airplane. To say the autopilot should not be used under
certain circumstances is one thing, but here we are coming close to the Fox
News ideal of posthumously condemning the pilot to 50 counts of first
degree for having used the autopilot.

Interesting, in that we tend to handfly the Mooney in IMC, using
autopilot only when we need a break if there's only one pilot on
board. It's a subjective thing I suppose, but hand flying does not
take a lot of effort en route (or most of the time, if truth be told)
and I'd not want to have to suddenly transition to hand flying in IMC
in the unlikely event the autopilot had a subtle failure.

On Feb 17, 12:23*am, VOR-DME wrote:
In article ,
says...





On Feb 16, 3:38*pm, VOR-DME wrote:
In article
,
says...

On Feb 15, 5:41*pm, Tman wrote:
Dudley Henriques wrote:
There's a very good chance the Boston crash might have been tailplane
icing.

Did you mean BUF or did I miss something in Boston?
T

Yes. I've been dealing with a Boston issue most of the day and my
senior moment quota kicked in. It was Buffalo.
DH

Oh thanks! Spent two hours on the NTSB database trying to figure what
Boston crash we were talking about! :-)

Sorry. Those "senior moments" can be annoying for sure. It's a shame
youth is wasted on such young people.
:-)))
-D

No harm done. We always learn something by going back through the NTSB
records! I was surprised to find how few accident records included both the
location "Boston" and the keyword "icing". Aside the FEDEX takeoff incident,
where ice caused physical damage to one of the engines, I learned that a
Skymaster crashed in 1975 departing Boston, probably because of airframe
icing. His intended destination? Buffalo :-)

I belong to a world-wide flight safety work group that uses the base
all the time. It can be useful as you say. Our work is primarily
involved with the low altitude aerobatic display environment but many
in our community are airline people and have a great interest in
anything that enhances the learning curve safety wise.
I was pleasantly surprised to discover that in our work group alone,
the interest in tailplane icing has increased since yesterday to the
point where information has been spreading throughout the low to
medium altitude turbo-prop scheduled and non- scheduled operations
world wide.
-DH

On Mon, 16 Feb 2009 13:42:52 -0800 (PST), Dudley Henriques wrote:

I belong to a world-wide flight safety work group that uses the base
all the time. It can be useful as you say. Our work is primarily
involved with the low altitude aerobatic display environment but many
in our community are airline people and have a great interest in
anything that enhances the learning curve safety wise.
I was pleasantly surprised to discover that in our work group alone,
the interest in tailplane icing has increased since yesterday to the
point where information has been spreading throughout the low to
medium altitude turbo-prop scheduled and non- scheduled operations
world wide.
-DH

There's something radically wrong here. Of course the horz stabil can
ice, a tail can ice. Of course there should be a sh**load of info on it
but I'll be damned if I know where it is. POH? Cessna 15x or 17x?
Diamonds?

On Mon, 16 Feb 2009 18:51:05 -0800, 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. . .

Explain to me how much more clearly I could state (especially in a
discussion group):

"Following the theory, for the sake of discussion, is this pilot error
and is it avoidable?"

On Feb 17, 1:43*am, VOR-DME wrote:
In article ,
says...



Interesting, in that we tend to handfly the Mooney in IMC, using
autopilot only when we need a break if there's only one pilot on
board. It's a subjective thing I suppose, but hand flying does not
take a lot of effort en route (or most of the time, if truth be told)
and I'd not want to have to suddenly transition to hand flying in IMC
in the unlikely event the autopilot had a subtle failure.

Interesting. I do not share your point of view, but I respect it.
I not only hand-fly, in training, but I (like others) fly partial panel, to
simulate vacuum failure (conventional systems) or electrical failure (glass
systems). In "real" flight, I use everything available, freeing up the xx% of
my brain that was used just maintaining heading and altitude to maintain a
higher-level vision of the progress of the flight. I believe this overall
vision is more important that the difficulty of transitioning to a degraded
control mode in the case of a system failure, partly because of the
unlikelihood of the latter.

There's more to our side of the story -- we like to hand fly! Our self
adminstered safety flights are a bit more challenging than those
administered by our cfi, esp w/r/t partial panel, instrument
failures, and unusual attitudes. I suspect the difference in safety
between our two methods would be hard to quantify. One of us could
type more loudly than the other, I suppose -- this is the usernet
after all. .

On Feb 16, 5:23*pm, Gezellig wrote:
On Mon, 16 Feb 2009 13:42:52 -0800 (PST), Dudley Henriques wrote:
I belong to a world-wide flight safety work group that uses the base
all the time. It can be useful as you say. Our work is primarily
involved with the low altitude aerobatic display environment but many
in our community are airline people and have a great interest in
anything that enhances the learning curve safety wise.
I was pleasantly surprised to discover that in our work group alone,
the interest in tailplane icing has increased since yesterday to the
point where information has been spreading throughout the low to
medium altitude turbo-prop scheduled and non- scheduled operations
world wide.
-DH

There's something radically wrong here. Of course the horz stabil can
ice, a tail can ice. Of course there should be a sh**load of info on it
but I'll be damned if I know where it is. POH? Cessna 15x or 17x?
Diamonds?

You're right. There should be much more written on the issue. NASA has
been working on it for quite a while now and in fact has done a film
piece on it for distribution throughout the aviation community.
Just in case you haven't seen the NASA piece, I've included a link on
it for you. It's worth watching!
http://video.google.com/videoplay?do...23060735779946

-DH

"VOR-DME" wrote

Besides that, just as a matter of intellectual honesty, we should give the
crew enough benefit of the doubt not to fall to the "it wouldn't have
happened to me. . ." fallacy - at least until all of the ifactual
information is in?

I fly IFR by hand in IMC for practice and recurrent training, but would not
subject trusting passengers to this risk. Instead I use the autopilot,
whose judicious use I consider to be one of the most important safety
devices in the airplane. To say the autopilot should not be used under
certain circumstances is one thing, but here we are coming close to the
Fox
News ideal of posthumously condemning the pilot to 50 counts of first
degree for having used the autopilot.

While I agree with your basic premise, (of not blaming the pilot before the
report is out) it is fact that they were still on auto, they knew there was
ice, it was against company policy to do so in ice, and it is a generally
accepted "fact" that flying on auto in ice can be very risky, indeed.

It seems only truthful to say that the pilots did something that was wrong,
and in this case, they bought the farm because of it.
--
Jim in NC