Wing De-Icing Question

[Robert11[_2_]]

Hello,

I guess de-icing is going to be a popular subject.

Question, please: On commercial jet airliners like, e.g., a 767 or 757, is
there any in-flight deicing system for the wing and tail surfaces, other
than a leading edge pneumatic boot ?

What about the "main," large upper surfaces ?

How in general is wing de-icing accomplished on these new, modern jets ?

Thanks,
Bob

[Morgans[_2_]]

"Robert11" > wrote in message
...
> Hello,
>
> I guess de-icing is going to be a popular subject.
>
> Question, please: On commercial jet airliners like, e.g., a 767 or 757,
> is there any in-flight deicing system for the wing and tail surfaces,
> other than a leading edge pneumatic boot ?
>
> What about the "main," large upper surfaces ?
>
> How in general is wing de-icing accomplished on these new, modern jets ?
>
Hot bypass air from the engines is what they use, in general. I have to
admit I do not know it the 787 is going to go truly all electric, or still
use hot engine air to heat the wings.

Once you get up to airliners of a larger size, the use of boots is not
common. In smaller turbine commuters, and in piston planes, (especially
pistons) there is not enough heat produced to heat wings.
--
Jim in NC

[Robert M. Gary]

On Feb 13, 1:44*pm, "Robert11" > wrote:
> Hello,
>
> I guess de-icing is going to be a popular subject.
>
> Question, please: *On commercial jet airliners like, e.g., a 767 or 757, is
> there any in-flight deicing system for the wing and tail surfaces, other
> than a leading edge pneumatic boot ?
>
> What about the "main," large upper surfaces ?
>
> How in general is wing de-icing accomplished on these new, modern jets ?
>
> Thanks,
> Bob

Jets don't typically have boots. Most use hot air stollen from the
engines to heat the leading edges. Some use a "leak" system to drip
anti-freeze like solution on the tail surfaces to avoid having to
plumb the hot air to the rear, although this is less common. I'm not
sure that I woudl call the type of plane that crashed less modern than
a 767 considering by-pass jet engines (the type in a 767) have been
around longer than turbo prop engines that were involed in this recent
crash.

-Robert

[K l e i n[_2_]]

On Feb 13, 3:36*pm, "Robert M. Gary" > wrote:
> On Feb 13, 1:44*pm, "Robert11" > wrote:
>
> > Hello,
>
> > I guess de-icing is going to be a popular subject.
>
> > Question, please: *On commercial jet airliners like, e.g., a 767 or 757, is
> > there any in-flight deicing system for the wing and tail surfaces, other
> > than a leading edge pneumatic boot ?
>
> > What about the "main," large upper surfaces ?
>
> > How in general is wing de-icing accomplished on these new, modern jets ?
>
> > Thanks,
> > Bob
>
> Jets don't typically have boots. Most use hot air stollen from the
> engines to heat the leading edges. Some use a "leak" system to drip
> anti-freeze like solution on the tail surfaces to avoid having to
> plumb the hot air to the rear, although this is less common. I'm not
> sure that I woudl call the type of plane that crashed less modern than
> a 767 considering by-pass jet engines (the type in a 767) have been
> around longer than turbo prop engines that were involed in this recent
> crash.
>
> -Robert

The more I hear about this, the more it sounds like tailplane icing.
Take a look at http://video.google.com/videoplay?docid=2238323060735779946
for a NASA produced video on the subject.

Note that this flight started its plunge right at or after the outer
marker. The outer marker is where you normally lower gear and flaps.
Lowering flaps is the thing that causes the tailplane stall if the
tailplane is iced up.

K l e i n

[Bertie the Bunyip[_24_]]

"Robert11" > wrote in
:

> Hello,
>
> I guess de-icing is going to be a popular subject.
>
> Question, please: On commercial jet airliners like, e.g., a 767 or
> 757, is there any in-flight deicing system for the wing and tail
> surfaces, other than a leading edge pneumatic boot ?
>
> What about the "main," large upper surfaces ?
>
> How in general is wing de-icing accomplished on these new, modern jets
> ?

on flight, generally, not at all. On most jets, only the wings and engines
have anti or de-icing and it's accomplished by bleeding hot air out of the
compressor section of the engines. The engine anti ice is used frequently,
but wing de icing is seldom used simply because ice seldom forms on the
wings in flight. There is no deicing for the tops of the wings in jets.


Bertie

[Bertie the Bunyip[_28_]]

"Morgans" > wrote in
:

>
> "Robert11" > wrote in message
> ...
>> Hello,
>>
>> I guess de-icing is going to be a popular subject.
>>
>> Question, please: On commercial jet airliners like, e.g., a 767 or
>> 757, is there any in-flight deicing system for the wing and tail
>> surfaces, other than a leading edge pneumatic boot ?
>>
>> What about the "main," large upper surfaces ?
>>
>> How in general is wing de-icing accomplished on these new, modern
>> jets ?
>>
> Hot bypass air from the engines is what they use, in general. I have
> to admit I do not know it the 787 is going to go truly all electric,
> or still use hot engine air to heat the wings.
>
> Once you get up to airliners of a larger size, the use of boots is not
> common. In smaller turbine commuters, and in piston planes,
> (especially pistons) there is not enough heat produced to heat wings.


yes, there is. there have been many pistons with hot wings, fjukkwit.


Bertie

[Bertie the Bunyip[_24_]]

K l e i n > wrote in
:

> On Feb 13, 3:36*pm, "Robert M. Gary" > wrote:
>> On Feb 13, 1:44*pm, "Robert11" > wrote:
>>
>> > Hello,
>>
>> > I guess de-icing is going to be a popular subject.
>>
>> > Question, please: *On commercial jet airliners like, e.g., a 767 or
>> > 7
> 57, is
>> > there any in-flight deicing system for the wing and tail surfaces,
>> > othe
> r
>> > than a leading edge pneumatic boot ?
>>
>> > What about the "main," large upper surfaces ?
>>
>> > How in general is wing de-icing accomplished on these new, modern
>> > jets
> ?
>>
>> > Thanks,
>> > Bob
>>
>> Jets don't typically have boots. Most use hot air stollen from the
>> engines to heat the leading edges. Some use a "leak" system to drip
>> anti-freeze like solution on the tail surfaces to avoid having to
>> plumb the hot air to the rear, although this is less common. I'm not
>> sure that I woudl call the type of plane that crashed less modern
>> than a 767 considering by-pass jet engines (the type in a 767) have
>> been around longer than turbo prop engines that were involed in this
>> recent crash.
>>
>> -Robert
>
> The more I hear about this, the more it sounds like tailplane icing.
> Take a look at
> http://video.google.com/videoplay?docid=2238323060735779946 for a NASA
> produced video on the subject.
>
> Note that this flight started its plunge right at or after the outer
> marker. The outer marker is where you normally lower gear and flaps.
> Lowering flaps is the thing that causes the tailplane stall if the
> tailplane is iced up.
>

Rubbish.

Bertie

[Dudley Henriques[_2_]]

On Feb 13, 4:44*pm, "Robert11" > wrote:
> Hello,
>
> I guess de-icing is going to be a popular subject.
>
> Question, please: *On commercial jet airliners like, e.g., a 767 or 757, is
> there any in-flight deicing system for the wing and tail surfaces, other
> than a leading edge pneumatic boot ?
>
> What about the "main," large upper surfaces ?
>
> How in general is wing de-icing accomplished on these new, modern jets ?
>
> Thanks,
> Bob

There's a very good chance the Boston crash might have been tailplane
icing.
DH

[cavedweller]

On Feb 14, 9:12*pm, Bertie the Bunyip > wrote:
> K l e i n > wrote :
>
>
>
>
>
> > On Feb 13, 3:36*pm, "Robert M. Gary" > wrote:
> >> On Feb 13, 1:44*pm, "Robert11" > wrote:
>
> >> > Hello,
>
> >> > I guess de-icing is going to be a popular subject.
>
> >> > Question, please: *On commercial jet airliners like, e.g., a 767 or
> >> > 7
> > 57, is
> >> > there any in-flight deicing system for the wing and tail surfaces,
> >> > othe
> > r
> >> > than a leading edge pneumatic boot ?
>
> >> > What about the "main," large upper surfaces ?
>
> >> > How in general is wing de-icing accomplished on these new, modern
> >> > jets
> > ?
>
> >> > Thanks,
> >> > Bob
>
> >> Jets don't typically have boots. Most use hot air stollen from the
> >> engines to heat the leading edges. Some use a "leak" system to drip
> >> anti-freeze like solution on the tail surfaces to avoid having to
> >> plumb the hot air to the rear, although this is less common. I'm not
> >> sure that I woudl call the type of plane that crashed less modern
> >> than a 767 considering by-pass jet engines (the type in a 767) have
> >> been around longer than turbo prop engines that were involed in this
> >> recent crash.
>
> >> -Robert
>
> > The more I hear about this, the more it sounds like tailplane icing.
> > Take a look at
> >http://video.google.com/videoplay?docid=2238323060735779946for a NASA
> > produced video on the subject.
>
> > Note that this flight started its plunge right at or after the outer
> > marker. *The outer marker is where you normally lower gear and flaps.
> > Lowering flaps is the thing that causes the tailplane stall if the
> > tailplane is iced up.
>
> Rubbish.
>
> Bertie- Hide quoted text -
>
> - Show quoted text -

The NASA study on tail stall notwithstanding?

[Gezellig]

On Sun, 15 Feb 2009 06:00:13 -0800 (PST), Dudley Henriques wrote:

> On Feb 13, 4:44*pm, "Robert11" > wrote:
>> Hello,
>>
>> I guess de-icing is going to be a popular subject.
>>
>> Question, please: *On commercial jet airliners like, e.g., a 767 or 757, is
>> there any in-flight deicing system for the wing and tail surfaces, other
>> than a leading edge pneumatic boot ?
>>
>> What about the "main," large upper surfaces ?
>>
>> How in general is wing de-icing accomplished on these new, modern jets ?
>>
>> Thanks,
>> Bob
>
> There's a very good chance the Boston crash might have been tailplane
> icing.
> DH

To explain the erratic flight behavior?

[Dudley Henriques[_2_]]

On Feb 15, 11:59*am, Gezellig > wrote:
> On Sun, 15 Feb 2009 06:00:13 -0800 (PST), Dudley Henriques wrote:
> > On Feb 13, 4:44*pm, "Robert11" > wrote:
> >> Hello,
>
> >> I guess de-icing is going to be a popular subject.
>
> >> Question, please: *On commercial jet airliners like, e.g., a 767 or 757, is
> >> there any in-flight deicing system for the wing and tail surfaces, other
> >> than a leading edge pneumatic boot ?
>
> >> What about the "main," large upper surfaces ?
>
> >> How in general is wing de-icing accomplished on these new, modern jets ?
>
> >> Thanks,
> >> Bob
>
> > There's a very good chance the Boston crash might have been tailplane
> > icing.
> > DH
>
> To explain the erratic flight behavior?

It's just a guess, but yes. I viewed a NASA film only this morning on
this issue. The key if correct would be that whatever happened
happened immediately after they went to 15 degrees of flaps. That
would have increased the aoa on the tail surface leading edge. That
leading edge is sharper than the wing leading edge and very
susceptible to icing. Assuming the boundary layer sep point was moving
aft on the stabilizer already, when they lowered the flaps they could
have easily exceeded the CLmax for the tail.
Even if this theory is correct, I'd be looking for additional factors
related to icing coupling to cause the autorotation they seemed to
have entered prior to impact.
It's all theory anyway. The NTSB will come up with something as they
progress with the investigation.
DH

[Tman[_2_]]

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

[Tman[_2_]]

Bertie the Bunyip wrote:
>>
>> Note that this flight started its plunge right at or after the outer
>> marker. The outer marker is where you normally lower gear and flaps.
>> Lowering flaps is the thing that causes the tailplane stall if the
>> tailplane is iced up.
>>
>
> Rubbish.
>

Uhh, which part of this is rubbish?
As I recall from a news account of the FDR, the loss of control was
immediately following gear / flap extension.

If it was the "outer marker is where you normally lower gear and flaps",
well yeah but I'm not sure that's the point.
T

[Dudley Henriques[_2_]]

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

[Bertie the Bunyip[_24_]]

cavedweller > wrote in
:

> On Feb 14, 9:12*pm, Bertie the Bunyip > wrote:
>> K l e i n > wrote
>> innews:2d099c70-cb73-40be-a62e-feb3015f5
> :
>>
>>
>>
>>
>>
>> > On Feb 13, 3:36*pm, "Robert M. Gary" > wrote:
>> >> On Feb 13, 1:44*pm, "Robert11" > wrote:
>>
>> >> > Hello,
>>
>> >> > I guess de-icing is going to be a popular subject.
>>
>> >> > Question, please: *On commercial jet airliners like, e.g., a 767
>> >> > o
> r
>> >> > 7
>> > 57, is
>> >> > there any in-flight deicing system for the wing and tail
>> >> > surfaces, othe
>> > r
>> >> > than a leading edge pneumatic boot ?
>>
>> >> > What about the "main," large upper surfaces ?
>>
>> >> > How in general is wing de-icing accomplished on these new,
>> >> > modern jets
>> > ?
>>
>> >> > Thanks,
>> >> > Bob
>>
>> >> Jets don't typically have boots. Most use hot air stollen from the
>> >> engines to heat the leading edges. Some use a "leak" system to
>> >> drip anti-freeze like solution on the tail surfaces to avoid
>> >> having to plumb the hot air to the rear, although this is less
>> >> common. I'm not sure that I woudl call the type of plane that
>> >> crashed less modern than a 767 considering by-pass jet engines
>> >> (the type in a 767) have been around longer than turbo prop
>> >> engines that were involed in this recent crash.
>>
>> >> -Robert
>>
>> > The more I hear about this, the more it sounds like tailplane
>> > icing. Take a look at
>> >http://video.google.com/videoplay?docid=2238323060735779946for a
>> >NASA
>> > produced video on the subject.
>>
>> > Note that this flight started its plunge right at or after the
>> > outer marker. *The outer marker is where you normally lower gear
>> > and flaps. Lowering flaps is the thing that causes the tailplane
>> > stall if the tailplane is iced up.
>>
>> Rubbish.
>>
>> Bertie- Hide quoted text -
>>
>> - Show quoted text -
>
> The NASA study on tail stall notwithstanding?

Well, OK not impossible, but Wing if anythng..


Bertie

[Bertie the Bunyip[_24_]]

Tman > wrote in news:Eq-
:

> Bertie the Bunyip wrote:
>>>
>>> Note that this flight started its plunge right at or after the outer
>>> marker. The outer marker is where you normally lower gear and flaps.
>>> Lowering flaps is the thing that causes the tailplane stall if the
>>> tailplane is iced up.
>>>
>>
>> Rubbish.
>>
>
> Uhh, which part of this is rubbish?
> As I recall from a news account of the FDR, the loss of control was
> immediately following gear / flap extension.
>
> If it was the "outer marker is where you normally lower gear and flaps",
> well yeah but I'm not sure that's the point.



Doesn't mean the tail stalled, In any case, it's the premature assumptions
that **** me off, right or wrong.



Bertie

[[email protected]]

On Feb 15, 4:23*pm, Dudley Henriques > wrote:
> On Feb 15, 11:59*am, Gezellig > wrote:
>
>
>
> > On Sun, 15 Feb 2009 06:00:13 -0800 (PST), Dudley Henriques wrote:
> > > On Feb 13, 4:44*pm, "Robert11" > wrote:
> > >> Hello,
>
> > >> I guess de-icing is going to be a popular subject.
>
> > >> Question, please: *On commercial jet airliners like, e.g., a 767 or 757, is
> > >> there any in-flight deicing system for the wing and tail surfaces, other
> > >> than a leading edge pneumatic boot ?
>
> > >> What about the "main," large upper surfaces ?
>
> > >> How in general is wing de-icing accomplished on these new, modern jets ?
>
> > >> Thanks,
> > >> Bob
>
> > > There's a very good chance the Boston crash might have been tailplane
> > > icing.
> > > DH
>
> > To explain the erratic flight behavior?
>
> It's just a guess, but yes. I viewed a NASA film only this morning on
> this issue. The key if correct would be that whatever happened
> happened immediately after they went to 15 degrees of flaps. That
> would have increased the aoa on the tail surface leading edge. That
> leading edge is sharper than the wing leading edge and very
> susceptible to icing. Assuming the boundary layer sep point was moving
> aft on the stabilizer already, when they lowered the flaps they could
> have easily exceeded the CLmax for the tail.
> Even if this theory is correct, I'd be looking for additional factors
> related to icing coupling to cause the autorotation they seemed to
> have entered prior to impact.
> It's all theory anyway. The NTSB will come up with something as they
> progress with the investigation.
> DH

Maybe a silly notion/question buuuut...if this (pitching/roll -this
from new reports as of 2/16) had occurred at a higher altitude, 7000
ft say, would the plane have entered a 'flat' spin? Was the impact
indicative of such?

[Robert11[_2_]]

Hello,

Not a Physicist, so please bear with me.

The posts here seem to imply that wing icing occurs (mainly), if not
exclusively, on the leading edges, and not on the upper or lower wing
surfaces.

Why ?

If it does occur on the upper surfaces in modern jet commercial aircraft, is
there also
hot bleed air available for this large surface, as there is for the leading
edges ?

If it does occur on modern turboprops, on the upper surface, there is
nothing they can do to remove it.
Right ?

Why did they say that a 180 degree turn "may" help break off ice ?

Thanks,
Bob
---------------------------------


"VOR-DME" > wrote in message
...
> 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! :-)
>

[Maxwell[_2_]]

> wrote in message
...
On Feb 15, 4:23 pm, Dudley Henriques > wrote:

Cool! Let's speculate on speculation.

[Dudley Henriques[_2_]]

On Feb 16, 8:01*am, wrote:
> On Feb 15, 4:23*pm, Dudley Henriques > wrote:
>
>
>
> > On Feb 15, 11:59*am, Gezellig > wrote:
>
> > > On Sun, 15 Feb 2009 06:00:13 -0800 (PST), Dudley Henriques wrote:
> > > > On Feb 13, 4:44*pm, "Robert11" > wrote:
> > > >> Hello,
>
> > > >> I guess de-icing is going to be a popular subject.
>
> > > >> Question, please: *On commercial jet airliners like, e.g., a 767 or 757, is
> > > >> there any in-flight deicing system for the wing and tail surfaces, other
> > > >> than a leading edge pneumatic boot ?
>
> > > >> What about the "main," large upper surfaces ?
>
> > > >> How in general is wing de-icing accomplished on these new, modern jets ?
>
> > > >> Thanks,
> > > >> Bob
>
> > > > There's a very good chance the Boston crash might have been tailplane
> > > > icing.
> > > > DH
>
> > > To explain the erratic flight behavior?
>
> > It's just a guess, but yes. I viewed a NASA film only this morning on
> > this issue. The key if correct would be that whatever happened
> > happened immediately after they went to 15 degrees of flaps. That
> > would have increased the aoa on the tail surface leading edge. That
> > leading edge is sharper than the wing leading edge and very
> > susceptible to icing. Assuming the boundary layer sep point was moving
> > aft on the stabilizer already, when they lowered the flaps they could
> > have easily exceeded the CLmax for the tail.
> > Even if this theory is correct, I'd be looking for additional factors
> > related to icing coupling to cause the autorotation they seemed to
> > have entered prior to impact.
> > It's all theory anyway. The NTSB will come up with something as they
> > progress with the investigation.
> > DH
>
> Maybe a silly notion/question buuuut...if this (pitching/roll -this
> from new reports as of 2/16) had occurred at a higher altitude, 7000
> ft say, would the plane have entered a 'flat' spin? *Was the impact
> indicative of such?

Difficult to say. I'm far from being the expert on transport aircraft.
My understanding is that if, and that is still a big IF, tailplane
icing was involved in the Buffalo accident, it was the lowering of the
flaps and the cfg change to the wing increasing the aoa on the tail
that was the factor actually taking them into stall. If that was the
cause, the actual breaking of the stall caused by the ice on various
leading edges could very well have taken them into uncontrolled auto
rotation. For that to happen, yaw had to be present at the stall.
The scenario above assumes low altitude due to the flap extension
factor.
At this stage in any accident investigation, it's always conjecture.
Already however, the seldom discussed issue of tailplane icing is
getting a lot of attention throughout the entire aviation community
and that alone is good for flight safety. The NTSB investigation will
provide the answer I'm sure.
Dudley Henriques

[a[_3_]]

On Feb 16, 8:01*am, "Robert11" > wrote:
> Hello,
>
> Not a Physicist, so please bear with me.
>
> The posts here seem to imply that wing icing occurs (mainly), if not
> exclusively, on the leading edges, and not on the upper or lower wing
> surfaces.
>
> Why ?
>
> If it does occur on the upper surfaces in modern jet commercial aircraft, is
> there also
> hot bleed air available for this large surface, as there is for the leading
> edges ?
>
> If it does occur on modern turboprops, on the upper surface, there is
> nothing they can do to remove it.
> Right ?
>
> Why did they say that a 180 degree turn "may" help break off ice ?
>
> Thanks,
> Bob
> ---------------------------------
>
> "VOR-DME" > wrote in message
>
> ...
>
>
>
> > 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! :-)- Hide quoted text -
>
> - Show quoted text -

Think for a moment about the airflow around thle wing. At one point
the air flows up and over, and a little lower on the leading edge if
flows down and under. There is a line then, the point where the flow
seperates, where there is little airflow at all. It's called the
stagnation point. If ice is going to form it will form where there's
not a lot of wind blowing the water away, that's why it forms on the
leading edges. You'll see, in icing conditions, ugly ice sticking out
from the leading edges first.

The magic of a 180 degree turn is, back where you came from there was
not ice forming -- go back there!

[Dudley Henriques[_2_]]

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

[Gezellig]

On Mon, 16 Feb 2009 05:58:24 -0800 (PST), a wrote:

> The magic of a 180 degree turn is, back where you came from there was
> not ice forming -- go back there!

??????????

[Gezellig]

On Sun, 15 Feb 2009 14:23:43 -0800 (PST), Dudley Henriques wrote:

> On Feb 15, 11:59*am, Gezellig > wrote:
>> On Sun, 15 Feb 2009 06:00:13 -0800 (PST), Dudley Henriques wrote:
>>> On Feb 13, 4:44*pm, "Robert11" > wrote:
>>>> Hello,
>>
>>>> I guess de-icing is going to be a popular subject.
>>
>>>> Question, please: *On commercial jet airliners like, e.g., a 767 or 757, is
>>>> there any in-flight deicing system for the wing and tail surfaces, other
>>>> than a leading edge pneumatic boot ?
>>
>>>> What about the "main," large upper surfaces ?
>>
>>>> How in general is wing de-icing accomplished on these new, modern jets ?
>>
>>>> Thanks,
>>>> Bob
>>
>>> There's a very good chance the Boston crash might have been tailplane
>>> icing.
>>> DH
>>
>> To explain the erratic flight behavior?
>
> It's just a guess, but yes. I viewed a NASA film only this morning on
> this issue. The key if correct would be that whatever happened
> happened immediately after they went to 15 degrees of flaps. That
> would have increased the aoa on the tail surface leading edge. That
> leading edge is sharper than the wing leading edge and very
> susceptible to icing. Assuming the boundary layer sep point was moving
> aft on the stabilizer already, when they lowered the flaps they could
> have easily exceeded the CLmax for the tail.
> Even if this theory is correct, I'd be looking for additional factors
> related to icing coupling to cause the autorotation they seemed to
> have entered prior to impact.
> It's all theory anyway. The NTSB will come up with something as they
> progress with the investigation.
> DH

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

I realize they can't see the tail but icing on the windshield was
reported.

I have icing, weather, an aircraft with a history of tail icing (due to
its design)....even if they had no stick inputs, do you go to flaps
knowing that you could possibly cause a sever pitch down and the
inevitable results?

[Gezellig]

On Mon, 16 Feb 2009 11:18:45 -0500, Gezellig wrote:

> On Sun, 15 Feb 2009 14:23:43 -0800 (PST), Dudley Henriques wrote:
>
>> On Feb 15, 11:59*am, Gezellig > wrote:
>>> On Sun, 15 Feb 2009 06:00:13 -0800 (PST), Dudley Henriques wrote:
>>>> On Feb 13, 4:44*pm, "Robert11" > wrote:
>>>>> Hello,
>>>
>>>>> I guess de-icing is going to be a popular subject.
>>>
>>>>> Question, please: *On commercial jet airliners like, e.g., a 767 or 757, is
>>>>> there any in-flight deicing system for the wing and tail surfaces, other
>>>>> than a leading edge pneumatic boot ?
>>>
>>>>> What about the "main," large upper surfaces ?
>>>
>>>>> How in general is wing de-icing accomplished on these new, modern jets ?
>>>
>>>>> Thanks,
>>>>> Bob
>>>
>>>> There's a very good chance the Boston crash might have been tailplane
>>>> icing.
>>>> DH
>>>
>>> To explain the erratic flight behavior?
>>
>> It's just a guess, but yes. I viewed a NASA film only this morning on
>> this issue. The key if correct would be that whatever happened
>> happened immediately after they went to 15 degrees of flaps. That
>> would have increased the aoa on the tail surface leading edge. That
>> leading edge is sharper than the wing leading edge and very
>> susceptible to icing. Assuming the boundary layer sep point was moving
>> aft on the stabilizer already, when they lowered the flaps they could
>> have easily exceeded the CLmax for the tail.
>> Even if this theory is correct, I'd be looking for additional factors
>> related to icing coupling to cause the autorotation they seemed to
>> have entered prior to impact.
>> It's all theory anyway. The NTSB will come up with something as they
>> progress with the investigation.
>> DH
>
> Following the theory, for the sake of discussion, is this pilot error
> and is it avoidable?
>
> I realize they can't see the tail but icing on the windshield was
> reported.
>
> I have icing, weather, an aircraft with a history of tail icing (due to
> its design)....even if they had no stick inputs, do you go to flaps
> knowing that you could possibly cause a sever pitch down and the
> inevitable results?

NTSB: Flight 3407 Was On Autopilot Before Accident

Mon, 16 Feb '09
Practice Violated Company Policy For Icing Conditions

A National Transportation Safety Board official confirmed Sunday that
downed Continental Express flight 3407 was being flown on autopilot at
the time of the crash, contrary to normal procedures.

In conjuction with FAA recommendations, NTSB spokesman Steve Chealander
said Colgan Air, the plane's operator, recommends that pilots manually
fly during all conditions... and requires them to do so when there's
evidence of severe icing.

"You may be able in a manual mode to sense something sooner than the
autopilot can sense it," Chealander told the Associated Press,
emphasizing the need to hand-fly the airplane to better feel how it's
really flying when conditions are critical.

An autopilot will trim out an aircraft, within its capabilities, to
compensate for changing conditions -- including airflow disturbances
caused by icing -- without the flight crew necessarily becoming aware of
any abnormalities.

[[email protected]]

On Feb 16, 9:18*am, Gezellig > wrote:
> On Sun, 15 Feb 2009 14:23:43 -0800 (PST), Dudley Henriques wrote:
> > On Feb 15, 11:59 am, Gezellig > wrote:
> >> On Sun, 15 Feb 2009 06:00:13 -0800 (PST), Dudley Henriques wrote:
> >>> On Feb 13, 4:44 pm, "Robert11" > wrote:
> >>>> Hello,
>
> >>>> I guess de-icing is going to be a popular subject.
>
> >>>> Question, please: On commercial jet airliners like, e.g., a 767 or 757, is
> >>>> there any in-flight deicing system for the wing and tail surfaces, other
> >>>> than a leading edge pneumatic boot ?
>
> >>>> What about the "main," large upper surfaces ?
>
> >>>> How in general is wing de-icing accomplished on these new, modern jets ?
>
> >>>> Thanks,
> >>>> Bob
>
> >>> There's a very good chance the Boston crash might have been tailplane
> >>> icing.
> >>> DH
>
> >> To explain the erratic flight behavior?
>
> > It's just a guess, but yes. I viewed a NASA film only this morning on
> > this issue. The key if correct would be that whatever happened
> > happened immediately after they went to 15 degrees of flaps. That
> > would have increased the aoa on the tail surface leading edge. That
> > leading edge is sharper than the wing leading edge and very
> > susceptible to icing. Assuming the boundary layer sep point was moving
> > aft on the stabilizer already, when they lowered the flaps they could
> > have easily exceeded the CLmax for the tail.
> > Even if this theory is correct, I'd be looking for additional factors
> > related to icing coupling to cause the autorotation they seemed to
> > have entered prior to impact.
> > It's all theory anyway. The NTSB will come up with something as they
> > progress with the investigation.
> > DH
>
> Following the theory, for the sake of discussion, is this pilot error
> and is it avoidable?
>
> I realize they can't see the tail but icing on the windshield was
> reported.
>
> I have icing, weather, an aircraft with a history of tail icing (due to
> its design)....even if they had no stick inputs, do you go to flaps
> knowing that you could possibly cause a sever pitch down and the
> inevitable results?

Now they're looking at the pilot's possibly having the
autopilot on during the descent into and during the icing conditions,
against company policy. Anyone who has flown an autopilot will know
that it isn't the smartest beast and can cause problems. See
http://www.google.com/hostednews/ap/article/ALeqM5hpSZzqkNMwZvX2xrejSSUOyBGCYgD96CNPN81

Dan

[a[_3_]]

On Feb 16, 11:11*am, Gezellig > wrote:
> On Mon, 16 Feb 2009 05:58:24 -0800 (PST), a wrote:
> > The magic of a 180 degree turn is, back where you came from there was
> > not ice forming -- go back there!
>
> ??????????

I may not have been clear. If you find yourself in icing conditions,
retreating (do a 180) is often a good option.

[Gezellig]

On Mon, 16 Feb 2009 09:06:22 -0800 (PST), a wrote:

> On Feb 16, 11:11*am, Gezellig > wrote:
>> On Mon, 16 Feb 2009 05:58:24 -0800 (PST), a wrote:
>>> The magic of a 180 degree turn is, back where you came from there was
>>> not ice forming -- go back there!
>>
>> ??????????
>
> I may not have been clear. If you find yourself in icing conditions,
> retreating (do a 180) is often a good option.

Thx!

[Gezellig]

On Mon, 16 Feb 2009 08:35:08 -0800 (PST),
wrote:

> Now they're looking at the pilot's possibly having the
> autopilot on during the descent into and during the icing conditions,
> against company policy. Anyone who has flown an autopilot will know
> that it isn't the smartest beast and can cause problems. See
> http://www.google.com/hostednews/ap/article/ALeqM5hpSZzqkNMwZvX2xrejSSUOyBGCYgD96CNPN81
>
> Dan

"The Dash 8 Q400 plane, operated by Colgan Air, was equipped with a
"stick shaker" and "stick pusher" mechanism that rattles the yoke to
warn the pilot if the plane is about to lose aerodynamic lift, a
condition called a stall. If not corrected in time, the mechanism
automatically pushes the stick forward to avert a stall.

Chealander said the plane was on autopilot until the "stick shaker" and
"stick pusher" kicked in, automatically putting the plane back in the
pilot's hands.

At some point, the pilot switched on an anti-stall device that increases
the speed of the plane by 20 knots and gives a pilot more margin to
recover from a stall if it occurs.

Asked whether the pilot might have overreacted by pulling the stick back
when it automatically went forward, Chealander said, "Yes, it's
possible."

================================================== =======================

Isn't this counter to pulling back on the yoke, cutting power and speed,
when you get nose pitch due to tail icing?

[Dudley Henriques[_2_]]

On Feb 16, 11:18*am, Gezellig > wrote:
> On Sun, 15 Feb 2009 14:23:43 -0800 (PST), Dudley Henriques wrote:
> > On Feb 15, 11:59*am, Gezellig > wrote:
> >> On Sun, 15 Feb 2009 06:00:13 -0800 (PST), Dudley Henriques wrote:
> >>> On Feb 13, 4:44*pm, "Robert11" > wrote:
> >>>> Hello,
>
> >>>> I guess de-icing is going to be a popular subject.
>
> >>>> Question, please: *On commercial jet airliners like, e.g., a 767 or 757, is
> >>>> there any in-flight deicing system for the wing and tail surfaces, other
> >>>> than a leading edge pneumatic boot ?
>
> >>>> What about the "main," large upper surfaces ?
>
> >>>> How in general is wing de-icing accomplished on these new, modern jets ?
>
> >>>> Thanks,
> >>>> Bob
>
> >>> There's a very good chance the Boston crash might have been tailplane
> >>> icing.
> >>> DH
>
> >> To explain the erratic flight behavior?
>
> > It's just a guess, but yes. I viewed a NASA film only this morning on
> > this issue. The key if correct would be that whatever happened
> > happened immediately after they went to 15 degrees of flaps. That
> > would have increased the aoa on the tail surface leading edge. That
> > leading edge is sharper than the wing leading edge and very
> > susceptible to icing. Assuming the boundary layer sep point was moving
> > aft on the stabilizer already, when they lowered the flaps they could
> > have easily exceeded the CLmax for the tail.
> > Even if this theory is correct, I'd be looking for additional factors
> > related to icing coupling to cause the autorotation they seemed to
> > have entered prior to impact.
> > It's all theory anyway. The NTSB will come up with something as they
> > progress with the investigation.
> > DH
>
> Following the theory, for the sake of discussion, is this pilot error
> and is it avoidable?
>
> I realize they can't see the tail but icing on the windshield was
> reported.
>
> I have icing, weather, an aircraft with a history of tail icing (due to
> its design)....even if they had no stick inputs, do you go to flaps
> knowing that you could possibly cause a sever pitch down and the
> inevitable results?

I would be hesitant to comment to that level not being current in type
or directly involved in the investigation. As the investigation
progresses there will be a deep look into the aircraft configuration
during the descent vs recommended procedures for conditions I'm sure.
-DH

[K l e i n[_2_]]

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

[Tman[_2_]]

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?

[VOR-DME]

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! :-)

[a[_3_]]

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.

[Dudley Henriques[_2_]]

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

[Gezellig]

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?

[Gezellig]

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?"

[a[_3_]]

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. .

[Dudley Henriques[_2_]]

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?docid=2238323060735779946

-DH

[Morgans[_2_]]

"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

[Gezellig]

On Tue, 17 Feb 2009 00:11:06 -0800, VOR-DME wrote:

> In article >, says...
>
>>
>>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?"
>
> Clear as a bell, but in my opinion misguided and unconstructive.
> Sorry to be so harsh about it, but do you really wish to establish "pilot
> error" and determine "whether it's avoidable" before a single piece of salient
> fact is laid on the table? Have you really no respect whatsoever for the
> factual portion of the investigation? Your impatience to conclude will
> automatically lead to erroneous conclusions. . .

Grab a reading comprehension manual.

Sheesh............

[Gezellig]

On Mon, 16 Feb 2009 14:57:50 -0800 (PST), Dudley Henriques wrote:

> 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?docid=2238323060735779946
>
> -DH

Like another poster, first time I had ever seen this and it is a great
piece. Should be std fare for PPLs imo, at least for turboprop multis.

[Bear Bottoms[_4_]]

On Mon, 16 Feb 2009 20:58:38 -0800, 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?

**** 'em.

Hey, AssClown, which part of "discussion" did you not understand? Why
not start your own Usenet gruppe and talk to yourself.

AssClown to AssClown,, come in.....
--
Bear Bottoms
Private Attorney General

[Dudley Henriques[_2_]]

On Feb 16, 7:23*pm, Gezellig > wrote:
> On Mon, 16 Feb 2009 14:57:50 -0800 (PST), Dudley Henriques wrote:
> > 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?docid=2238323060735779946
>
> > -DH
>
> Like another poster, first time I had ever seen this and it is a great
> piece. Should be std fare for PPLs imo, at least for turboprop multis.

I sent it out internationally through our pipeline this morning. It's
being distributed as we speak.
-DH

[Bear Bottoms[_4_]]

On Tue, 17 Feb 2009 00:03:27 -0800, VOR-DME wrote:

> Sorry for the /null/ post!!

Onlyh an AssClown..........

> I like to hand fly too.

Hand fly or hand job, AssClown?

> Insisted on it in my IR training. NDB approaches IMC as
> well. But I won't subject my passengers to increased risk just because I think
> it's more challenging for myself. IS THAT CLEAR? I*S T*H*A*T C*L*E*A*R*?? :-)

Crystal.

Are youh an AssClown?

A*S*S*C*L*O*W*N* ?

Do I **** in the woods?
--
Bear Bottoms
Private Attorney General

[Bear Bottoms[_4_]]

On Mon, 16 Feb 2009 18:51:05 -0800, VOR-DME wrote:

> This discussion is rapidly running in the wrong direction.

Try cupping your balls when you stroke your wiener, AssClown.

> 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,

Good then STFU.

AssClown.
--
Bear Bottoms
Private Attorney General

[cavedweller]

On Feb 17, 3:23*am, VOR-DME > wrote:
> In article >,
> says...
>
>
>
> >The NASA study on tail stall notwithstanding?
>
> In this case I think Gezellig is right.
> After the high-profile Roselawn (ATR) accident a few years ago, and the Vickers
> Viscount accidents dating back to 1954, we have had ample time to improve our
> icing awareness, particularly for the most vulnerable aircraft/mission
> profiles, and if the truth be known we don't have much to show for it . .

[cavedweller]

On Feb 17, 4:53*am, VOR-DME > wrote:
> In article >,
> says...
>
> >On Feb 17, 3:23*am, VOR-DME > wrote:
> >> In article
>
> >,
>
>
>
> >> says...
>
> >> >The NASA study on tail stall notwithstanding?
>
> >> In this case I think Gezellig is right.
> >> After the high-profile Roselawn (ATR) accident a few years ago, and the
> Vickers
> >> Viscount accidents dating back to 1954, we have had ample time to improve
> our
> >> icing awareness, particularly for the most vulnerable aircraft/mission
> >> profiles, and if the truth be known we don't have much to show for it .. . .
>
> >Umm...I was questioning Bertie....Gezellig's post was down thread.
> >Attribution, attribution.......
>
> Sorry - I dont receive "Bertie" or "Mxsmanic" or any responses to these
> self-styled, self-sufficient spammers. The filters I have developed leave me in
> ignorant bliss with regard to these intellectually impoverished ignoramuses.
> Don't know how your's got through. *If you are involved in discussion with
> same, frequency change is approved - go away.

I don't indulge with Bertie much either but in this thread I was
curious about what his reaction to a previous poster hence my question
to him. I didn't realize I needed your permission to do that . I
haven't seen your 'nym on here much in the past, and that's been
without benefit of filters.....just lucky, I guess.

[VOR-DME]

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. . .

[VOR-DME]

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.

[VOR-DME]

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 :-)

[Austin The Geeker Whitten ©¿©¬]

On Tue, 17 Feb 2009 01:53:42 -0800, VOR-DME wrote:

> In article >,
> says...
>>
>>
>>On Feb 17, 3:23*am, VOR-DME > wrote:
>>> In article
> >,
>>> says...
>>>
>>>
>>>
>>> >The NASA study on tail stall notwithstanding?
>>>
>>> In this case I think Gezellig is right.
>>> After the high-profile Roselawn (ATR) accident a few years ago, and the
> Vickers
>>> Viscount accidents dating back to 1954, we have had ample time to improve
> our
>>> icing awareness, particularly for the most vulnerable aircraft/mission
>>> profiles, and if the truth be known we don't have much to show for it . . .
>>
>>Umm...I was questioning Bertie....Gezellig's post was down thread.
>>Attribution, attribution.......
>
> Sorry - I dont receive "Bertie" or "Mxsmanic" or any responses to these
> self-styled, self-sufficient spammers. The filters I have developed leave me in
> ignorant bliss with regard to these intellectually impoverished ignoramuses.
> Don't know how your's got through. If you are involved in discussion with
> same, frequency change is approved - go away.

Yessir and that means you fukk up and post AssClown reponses to the
wrong peoples.

AssClown.
--
Austin Whitten, President; Geeks-In-Route, Inc;
3808 Gunn Hwy Ste C Tampa, FL 33618 866-661-GEEK Ext 701
813-480-0103 Mobile 813-388-4902 Fax
www.geeks-in-route.com

[VOR-DME]

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.

[VOR-DME]

In article >,
says...
>
>
>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. .

[VOR-DME]

In article >,
says...
>
>
>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. .

Sorry for the /null/ post!!
I like to hand fly too. Insisted on it in my IR training. NDB approaches IMC as
well. But I won't subject my passengers to increased risk just because I think
it's more challenging for myself. IS THAT CLEAR? I*S T*H*A*T C*L*E*A*R*?? :-)

[VOR-DME]

In article >, says...

>
>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?"

Clear as a bell, but in my opinion misguided and unconstructive.
Sorry to be so harsh about it, but do you really wish to establish "pilot
error" and determine "whether it's avoidable" before a single piece of salient
fact is laid on the table? Have you really no respect whatsoever for the
factual portion of the investigation? Your impatience to conclude will
automatically lead to erroneous conclusions. . .

[VOR-DME]

In article >,
says...
>
>
>
>
>The NASA study on tail stall notwithstanding?


In this case I think Gezellig is right.
After the high-profile Roselawn (ATR) accident a few years ago, and the Vickers
Viscount accidents dating back to 1954, we have had ample time to improve our
icing awareness, particularly for the most vulnerable aircraft/mission
profiles, and if the truth be known we don't have much to show for it . . .

[VOR-DME]

In article >, says...
>
>
>Hello,
>
>Not a Physicist, so please bear with me.
>
>The posts here seem to imply that wing icing occurs (mainly), if not
>exclusively, on the leading edges, and not on the upper or lower wing
>surfaces.
>
>Why ?
>
>If it does occur on the upper surfaces in modern jet commercial aircraft, is
>there also
>hot bleed air available for this large surface, as there is for the leading
>edges ?
>
>If it does occur on modern turboprops, on the upper surface, there is
>nothing they can do to remove it.
>Right ?

Not quite.
Good points though. The "hot wing" solution used on high-flyers is to heat the
leading edges so hot that freezing particles will not only remain above
freezing, but simply vaporize to avoid run-back re-freezing. Yes, that means
very hot, and lots of energy to burn.

The turboprop and high-performance piston solution is to use de-icing boots
that inflate to break off ice after it has formed. There is ongoing debate
about "ice bridging" the theory that the boots may inflate too soon, and that
ice will form around or over the inflated profile so as to render the boot
cycling ineffective. "Official" and "user" opinions vary as often as the
seasons change on this one. Not to be neglected is the "TKS" system, more
popular on high-performance pistons than on turboprops, which weeps de-icing
fluid across the wings through millions (yes, millions) of micro-pores drilled
in the leading edges. Popular in Mooneys for years, it is gradually gaining
ground and may actually find application in passenger tirboprops in years to
come. . . There's a significant weight penalty for that de-icing fluid, and
when it's gone, it's gone. . .

[VOR-DME]

In article >, says...

>
>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
>
>

You may end up being right, but today we simply do not have the factual base to
substantiate that claim. The autopilot today is so integrated into normal
flight operations that simply "turning it off" would require out of the
ordinary conditions, which have yet to be demonstrated for the flight in
question. What you claim to be "only truthful" to me is as yet
unsubstantiated.

[Dave Doe]

In article <5ce52bc4-6f80-4f81-802a-dee4be16d346
@h20g2000yqn.googlegroups.com>, says...
> 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?docid=2238323060735779946

A very good video, I have emailed it to some Air New Zealand folk, and
hope they distribute it around.

--
Duncan

[VOR-DME]

In article >,
says...
>
>
>On Feb 17, 3:23*am, VOR-DME > wrote:
>> In article
>,
>> says...
>>
>>
>>
>> >The NASA study on tail stall notwithstanding?
>>
>> In this case I think Gezellig is right.
>> After the high-profile Roselawn (ATR) accident a few years ago, and the
Vickers
>> Viscount accidents dating back to 1954, we have had ample time to improve
our
>> icing awareness, particularly for the most vulnerable aircraft/mission
>> profiles, and if the truth be known we don't have much to show for it . . .
>
>Umm...I was questioning Bertie....Gezellig's post was down thread.
>Attribution, attribution.......

Sorry - I dont receive "Bertie" or "Mxsmanic" or any responses to these
self-styled, self-sufficient spammers. The filters I have developed leave me in
ignorant bliss with regard to these intellectually impoverished ignoramuses.
Don't know how your's got through. If you are involved in discussion with
same, frequency change is approved - go away.

[VOR-DME]

In article >,
says...
>
>

>
>I don't indulge with Bertie much either but in this thread I was
>curious about what his reaction to a previous poster hence my question
>to him. I didn't realize I needed your permission to do that . I
>haven't seen your 'nym on here much in the past, and that's been
>without benefit of filters.....just lucky, I guess.
>


OK I apologize.
I admit I'm a bit peeved about what some self-indulgent guys have done to
normal exchange and discourse here. . .

[cavedweller]

On Feb 17, 6:38*am, VOR-DME > wrote:
> In article >,
> says...
>
>
>
> >I don't indulge with Bertie much either but in this thread I was
> >curious about what his reaction to a previous poster hence my question
> >to him. *I didn't realize I needed your permission to do that . *I
> >haven't seen your 'nym on here much in the past, and that's been
> >without benefit of filters.....just lucky, I guess.
>
> OK I apologize.
Roger that........
..

[cavedweller]

On Feb 17, 12:43*am, Austin "The Geeker" Whitten ©¿©¬ <aus...@geeks-
in-route.com> wrote:

>
> Yessir and that means you fukk up and post AssClown reponses to the
> wrong peoples.
>
> AssClown.
> --
> Austin Whitten, President; Geeks-In-Route, Inc;
> 3808 Gunn Hwy Ste C Tampa, FL 33618 866-661-GEEK Ext 701
> 813-480-0103 Mobile 813-388-4902 Faxwww.geeks-in-route.com

Such a sterling contribution..............not.

[Dudley Henriques[_2_]]

On Feb 17, 4:41*am, Dave Doe > wrote:
> In article <5ce52bc4-6f80-4f81-802a-dee4be16d346
> @h20g2000yqn.googlegroups.com>, says...
>
>
>
> > 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?docid=2238323060735779946
>
> A very good video, I have emailed it to some Air New Zealand folk, and
> hope they distribute it around.
>
> --
> Duncan

Flight safety works in many mysterious ways sometimes. An accident
always causes discussion and movement in the community. The
speculation of course is seldom useful and can actually be detrimental
in certain cases, but the exposure and subsequent distribution of
flight safety issues like tailplane icing that don't get much press
every day can be a VERY positive factor in increasing awareness of
these issues.
Spreading the word is always helpful.
-DH

[Bertie the Bunyip[_24_]]

VOR-DME > wrote in
:

> In article
> >,
> says...
>>
>>
>>
>>
>>The NASA study on tail stall notwithstanding?
>
>
> In this case I think Gezellig is right.

And, it appears, you were both wrong...


Bertie

[Bertie the Bunyip[_24_]]

VOR-DME > wrote in
:

> In article
> >,
> says...
>>
>>
>>On Feb 17, 3:23*am, VOR-DME > wrote:
>>> In article
> >,
>>> says...
>>>
>>>
>>>
>>> >The NASA study on tail stall notwithstanding?
>>>
>>> In this case I think Gezellig is right.
>>> After the high-profile Roselawn (ATR) accident a few years ago, and
>>> the
> Vickers
>>> Viscount accidents dating back to 1954, we have had ample time to
>>> improve
> our
>>> icing awareness, particularly for the most vulnerable
>>> aircraft/mission profiles, and if the truth be known we don't have
>>> much to show for it . . .
>>
>>Umm...I was questioning Bertie....Gezellig's post was down thread.
>>Attribution, attribution.......
>
> Sorry - I dont receive "Bertie" or "Mxsmanic" or any responses to
> these self-styled, self-sufficient spammers. The filters I have
> developed leave me in ignorant bliss


Ah, ignorant blss, how nice for you.


Bertie