SE airplanes in clouds - near freezing level

Wouldn't the condensation freeze just as readily, inside the vented volume?

Hmmm... that's why I fly them rather than design them.

Jose
--
"There are 3 secrets to the perfect landing. Unfortunately, nobody knows
what they are." - (mike).
for Email, make the obvious change in the address.

Stan Prevost wrote
Thanks for that little story, Bob. You are the only person I have
ever heard report the same kind of occurence. I have been accused of
lying, even though it seems obvious that it will occur.

In the B-707, after an ocean crossing, we always landed with 1/4" of
frost on the bottom surface of the wings.

Bob Moore

Thanks, Bob and others, for your corroboration.


"Bob Moore" wrote in message
46.128...
Stan Prevost wrote
Thanks for that little story, Bob. You are the only person I have
ever heard report the same kind of occurence. I have been accused of
lying, even though it seems obvious that it will occur.

In the B-707, after an ocean crossing, we always landed with 1/4" of
frost on the bottom surface of the wings.

Bob Moore

"Peter" wrote in message ...


Then we get onto the thorny subject of determining cloud tops in
Europe.... but let's not confuse the Americans too much, with their
superior weather services

I dunno about services, but perhaps America has superior *weather*.

Doug wrote:
The only situation that is deemed to be even slightly "ok" is to
descend from VMC down through a possible icing layer 1000' thick on
approach where you have weather report and know you can land, where
they are saying "light rime". That might be ok. People do it and get
away with it.

No, if the assigned altitude is still well above the MEA and warmer
air, its fine. Sometimes you have to tell ATC you can't decend to
12,000 but can take 8,000 if the MEA is only 3,000.

My experience with ice is you can't really predict it. If it's below
freezing and you are in a cloud or it's raining or snowing, you will
probably get it. And without a known ice airplane, you will NOT WANT TO
BE THERE!!

Yes, but once you start using your IFR ticket you'll find that you
either spend the winter on the ground or have the occasional ice
encounter. The trick is to keep outs available.

-Robert, CFII

Mark Hansen wrote:
On 12/22/06 15:49, Frank Stutzman wrote:
Doug wrote:
You ice up, can't climb and are forced to descend into unknown
terrain/ceilings. Definitely DON'T do that.

Given enough ice, you don't really have any other options.


I read his comment as "Don't allow yourself to get into this
situation in the first place."

Of course, once you're there, there's no going back ;-\

Personally, if I have warm MEA's below me I don't worry about it too
much. You just need to keep outs. Being able to decend into warm air is
an out. It varies greatly with the type of clouds you are in too.
Stratus clouds have large areas of ice but thin altitudes. CU clouds
tend to have verticle ice for thousands of feet but you pass through
them quickly. Mixed of course is the worse.
From practicle point of view there are two types of instrument pilots.
Those that have encountered ice and those that keep their instrument
ticket at home.

-Robert

On 26 Dec 2006 11:06:07 -0800, "Robert M. Gary"
wrote:


Doug wrote:
The only situation that is deemed to be even slightly "ok" is to
descend from VMC down through a possible icing layer 1000' thick on
approach where you have weather report and know you can land, where
they are saying "light rime". That might be ok. People do it and get
away with it.

No, if the assigned altitude is still well above the MEA and warmer
air, its fine. Sometimes you have to tell ATC you can't decend to
12,000 but can take 8,000 if the MEA is only 3,000.

My experience with ice is you can't really predict it. If it's below
freezing and you are in a cloud or it's raining or snowing, you will
probably get it. And without a known ice airplane, you will NOT WANT TO
BE THERE!!

Yes, but once you start using your IFR ticket you'll find that you
either spend the winter on the ground or have the occasional ice
encounter. The trick is to keep outs available.

IFR?

As a student (with instructor) we stayed strictly VMC, but still
brought a 150 back looking like a popsicle. Coming in to land it was
warm enough to start melting the ice. The stuff was coming off in
chunks that were flying back and hitting the tail. It sounded like a
trash can falling over.

Michigan and the Great Lakes in general are known for lake effect
storms. They can pop up suddenly and be isolated of cover wide areas.
This was about a week or so before my solo cross country.

As luck would have it, A whole bunch of lake effect snow storms popped
up between Cheboygan and Traverse City on the solo cross country. Even
with a detour to the south I still got bounced around a lot, but that
exposure to ice and lake effect storms really made the cross country
much more relaxed than it would have been otherwise.

That was an interesting cross country. I had to refuel twice.

You need those "outs" even as a VFR pilot. People generally think of
weather changing slowly, but even watching as closely as I do I've
been caught a couple of times. In many areas the weather can go from
great to IMC in a matter of minutes. If you know the conditions you
should have a good idea as to the shortest way out and what
frequencies to use to make sure.




-Robert, CFII
Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

Roger wrote:
On 26 Dec 2006 11:06:07 -0800, "Robert M. Gary"
wrote:
Michigan and the Great Lakes in general are known for lake effect
storms. They can pop up suddenly and be isolated of cover wide areas.
This was about a week or so before my solo cross country.

A very good reason to ask about weather from a local before flying in
any wx. I'm very familiar with California and the entire SW region and
Mexico. I can talk to you about summer TS management, Mexican monsoons,
etc but I can't tell you about Michigan wx. I would seek advice before
flying in that area. The WX in the Western part of the U.S. is
typically very predictable. My understanding is that is not the case
East of the rockies.
-Robert, CFII

One question I have is what is "warmer" air? If I climb to freezing
temps in the clouds (which I have done), is descending to an altitude
that is maybe 2C sufficient to prevent further icing? From my
experience, the answer appears to be that this is sufficient, but I'm
wondering if the surfaces are still cold enough to allow ice to build.

-Brian

Robert M. Gary wrote:

No, if the assigned altitude is still well above the MEA and warmer
air, its fine. Sometimes you have to tell ATC you can't decend to
12,000 but can take 8,000 if the MEA is only 3,000.

Brian wrote:

One question I have is what is "warmer" air? If I climb to freezing
temps in the clouds (which I have done), is descending to an altitude
that is maybe 2C sufficient to prevent further icing? From my
experience, the answer appears to be that this is sufficient, but I'm
wondering if the surfaces are still cold enough to allow ice to build.

It sure depends on the time beeing in the cold. A surface which has
collected ice but sees 1°C or 2°C "warm" air or water will definetly
melt after some time.
A certain delay might be caused (as we learned) with subcooled
fuel-(tanks) as the mass is much bigger. (So far lasts my "theory", as
I posted the topic to learn from the cloud pokers)

How about the "Freezing Fog" which the METARS show regularly since two
weeks over here in Europe ?
We have a 0°C .. 5°C surface temperature with a stable high pressure
system on top. Variable winds of 2kts and morning / evening fog, with a
lifting during the day to max. 500 feet in haze. On top (in 3000 feet)
we need sun cream!

How dangerous is freezing fog in such a small layer ??