SE airplanes in clouds - near freezing level

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.

--
Frank Stutzman
Bonanza N494B "Hula Girl"
Hood River, OR

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 ;-\


--
Mark Hansen, PP-ASEL, Instrument Airplane
Cal Aggie Flying Farmers
Sacramento, CA

-----Original Message-----
From: Roy Smith ]
Posted At: Friday, December 22, 2006 3:18 PM
Posted To: rec.aviation.ifr
Conversation: SE airplanes in clouds - near freezing level
Subject: SE airplanes in clouds - near freezing level

"Bob Gardner" wrote:
Jim Carter's experience is telling. When a cold-soaked airframe
descends
into the clouds it is going to collect a lot of ice in a hurry.
Where
does
the "quickly warmed" idea come from?

The thin sheet metal skin on the plane warms up fast. It's the fuel
in
the
tanks that hold the cold. So, obviously, the answer is to make sure
you
don't have any fuel left when you start your descent :-)


Now there's a different approach to the problem -- can't say that I want
to try it though. Very unique answer Roy. ;-}

-----Original Message-----
From: Jose ]
Posted At: Friday, December 22, 2006 4:22 PM
Posted To: rec.aviation.ifr
Conversation: SE airplanes in clouds - near freezing level
Subject: SE airplanes in clouds - near freezing level

The
thin skin without any thermal mass beneath it apparently warmed
rapidly
enough to accumulate little and shed it, whereas the fuel tanks had
enough
thermal mass to keep the ice frozen.

So, suppose the fuel tanks were insulated from the skin by about half
an
inch of (vented?) air... that should solve the problem, no? (albeit
at
a weight cost)
--
"There are 3 secrets to the perfect landing. Unfortunately, nobody
knows
what they are." - (mike).
for Email, make the obvious change in the address.

It might solve some of the problem, but in our case the upslope cumulus
was pretty unstable. The visible moisture had risen well above the
altitude (temp point) where it should have already turned to ice, so
when we stuck our aircraft into the moisture it quickly adhered to the
entire exterior.

I suppose if you were descending into warmer air the ice would not
accumulate anywhere except on pieces that took a while to warm up or in
areas of reduced pressure. On the other hand, if you are descending into
or flying through moisture that is still liquid but cooling rapidly you
are going to encourage cooling with your cold airframe -- and have a
souvenir to show for it.

"Jose" wrote in message
. net...
The thin skin without any thermal mass beneath it apparently warmed
rapidly enough to accumulate little and shed it, whereas the fuel tanks
had enough thermal mass to keep the ice frozen.

So, suppose the fuel tanks were insulated from the skin by about half an
inch of (vented?) air... that should solve the problem, no? (albeit at a
weight cost)

Probably. If it is indeed a problem.

"Jose" wrote in message . net...
The
thin skin without any thermal mass beneath it apparently warmed rapidly
enough to accumulate little and shed it, whereas the fuel tanks had enough
thermal mass to keep the ice frozen.

So, suppose the fuel tanks were insulated from the skin by about half an
inch of (vented?) air... that should solve the problem, no? (albeit at
a weight cost)
--

How would the vented air behave differently from the free air?
Wouldn't the condensation freeze just as readily, inside the vented volume?

"Bob Gardner" wrote in message
...
BTDT, in a Lear descending into Baton Rouge after a flight in the high 30
flight levels. Mucho ice on the bottoms of the wings.


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.

How would the vented air behave differently from the free air?
Wouldn't the condensation freeze just as readily, inside the vented volume?

Vented air would be at ambient temperature. Trapped air would probably
be at equilibrium with the fuel tank. If you are descending into warmer
air, it gives you an edge.

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.

"John R. Copeland" wrote in message
...
"Jose" wrote in message
. net...
The
thin skin without any thermal mass beneath it apparently warmed rapidly
enough to accumulate little and shed it, whereas the fuel tanks had
enough
thermal mass to keep the ice frozen.

So, suppose the fuel tanks were insulated from the skin by about half an
inch of (vented?) air... that should solve the problem, no? (albeit at
a weight cost)
--

How would the vented air behave differently from the free air?
Wouldn't the condensation freeze just as readily, inside the vented volume?


Vented air would probably add ice inside the wing, but would not disturb
the aerodynamics.

"Stan Prevost" wrote in message ...

"Bob Gardner" wrote in message
...
BTDT, in a Lear descending into Baton Rouge after a flight in the high 30
flight levels. Mucho ice on the bottoms of the wings.


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.


We pilots of Cessna tip-tank twins would support you too, Stan.
On ground after a high flight, the fuel level in the tip tanks is clearly evident.
Usually it's only condensation, but sometimes it can be clear ice.