Icy Runways

Newps writes:

The snow cover has little, if anything, to do with the daytime temps and
nothing at all with nighttime temps.

Tell that to people in Greenland and Siberia.

--
Transpose mxsmanic and gmail to reach me by e-mail.

Jay Honeck wrote:


Well, generally speaking, a structure that is designed to fold is going
to be inherently weaker than one that is not.


No, absolutely not. The Cessna 180/185 gear is famous for folding under
the plane if the plane gets sideways. And that's what we're talking
about, getting sideways. If you're just talking about the standard
vertical loads than I still want my Bo gear rather than the 182 I used
to have. The Bo is much more stout than it needs to be whereas the 182
is merely stout enough. That's why during a prepurchase for a 182 you
better look at the main gear attach points. My 182 had that area
repaired after a hard landing decades ago. You don't run into those
problems with a Bo and as a rule retracts don't fold a gear because of a
hard landing.



There are certainly ways
to minimize this problem, but a solid piece of steel is going to be
stronger than a similar-sized one that has a hinge (or three) built
into it.

You really need to see how the gear is attached to the plane. It's not
the leg that breaks but the connection to the airframe.

Mxsmanic wrote:

Newps writes:


The snow cover has little, if anything, to do with the daytime temps and
nothing at all with nighttime temps.


Tell that to people in Greenland and Siberia.




What for? Melt all the snow there and the temp would remain largely
unchanged. Dump all that snow on the Virgin Islands and the temp would
remain the same.

Newps writes:

What for? Melt all the snow there and the temp would remain largely
unchanged. Dump all that snow on the Virgin Islands and the temp would
remain the same.

No, the temperature would change. A large part of surface
temperatures depends on heating from solar radiation, and dark
surfaces absorb more radiation than light surfaces. One reason snow
often lingers for such a long time on the ground is that it reflects a
great deal of the solar radiation that might otherwise melt it if it
were absorbed.

--
Transpose mxsmanic and gmail to reach me by e-mail.

The snow cover has little, if anything, to do with the daytime temps and
nothing at all with nighttime temps.

Wrong. It's been a long time since I took meteorology (OMG: it's been
27 years. Sheesh, I'm getting old...), but I still remember a thing or
three.

And you don't have to chart lapse rates and pressure gradients to prove
it. In your mind simply compare 500,000 square miles of bare land
versus 500,000 miles of ice-covered land. That snow and ice has a
significant impact on temperatures, and the ability of the sun to warm
the land.

Even when a warm front moves in from the south, that snow keeps surface
temperatures quite a bit lower. In short, the impact of a region-wide
snow cover (like has happened in the upper Midwest over the last two
weeks) is felt immediately.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

Icy Runways... The true proof of whether a pilot's landing and take
off techniques are good.:-))

Right now the only place I could get enough traction to do a runup
would be in the hangar.
Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

On Mon, 22 Jan 2007 11:27:15 -0700, Newps wrote:



Jay Honeck wrote:


Once you've got a layer of white ice reflecting away all the solar
heat, the temperature can just plummet.



The snow cover has little, if anything, to do with the daytime temps and
nothing at all with nighttime temps.

Snow cover has a lot to do with the temps and how fast they can
change. The lack of snow and ice is why the perma frost line has
moved over 200 miles north and about 20% of the pack ice in the Artic
Ocean has melted. The polar route now exists in the summer.

Snow does two things with temperature. It reflects sunlight instead of
absorbing it for heating. This reflected sunlight is not absorbed by
the atmosphere. It also insulates the ground. The ground can be
frozen two feet down. Put two feet of snow on it and within a week to
10 days the ground will no longer be frozen. That's when you get the
car stuck and instead of finding solid ground undeneath you hit mud.


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

Jay Honeck wrote:
Here are a few pix of our icy taxiways here in Iowa City, for you guys
who don't normally see this stuff:

Looks just like the ice "The Little French Girl" slipped on two years
ago and separated her shoulder as she reached out to grab the strut
while preflighting the 182. :-))

Well, generally speaking, a structure that is designed to fold is going
to be inherently weaker than one that is not.


No, absolutely not. The Cessna 180/185 gear is famous for folding under
the plane if the plane gets sideways. And that's what we're talking
about, getting sideways. If you're just talking about the standard
vertical loads than I still want my Bo gear rather than the 182 I used
to have. The Bo is much more stout than it needs to be whereas the 182
is merely stout enough. That's why during a prepurchase for a 182 you
better look at the main gear attach points. My 182 had that area
repaired after a hard landing decades ago. You don't run into those
problems with a Bo and as a rule retracts don't fold a gear because of a
hard landing.

Is is hard to find a stronger system than the Bo's trailing links.

Peter

Jay Honeck wrote:
And people wonder why I moved to the Desert SW.
Winds today, 20G40.


Icy runways or taxiways are definitely not fun. Flyling on icy runways
makes one truly appreciate the stoutness of fixed landing gear.

When you can't do a run-up without sliding, you know it's gonna be a
fun flight...

I don't mind icy runways. The ones I don't like are ones that are part
ice and part asphalt. If they are all ice or hard packed snow, you can
make the takeoff and landing roll in a crab and not stress the gear much
at all. It is only if you had a bare patch that things can get ugly. I
used to fly a lot on snow covered runways in fairly strong winds and it
was a piece of cake as long as the runway was ALL snow or ice.


Matt