Iced up Cirrus crashes

"Dan Luke" wrote in

The more of these Cirrus accidents I read about, the more I'm convinced
that Cirrus has a serious marketing/training problem:

Nobody cares. Your opinions are of no interest to the world at large. Do
you have stats to back your claim?

chirp

moo

Montblack wrote:
("greenwavepilot" wrote)

snip

Michael, I am training in a Diamond DA-20 C1, incidentally, the only
composite airplane on my flight schools ramp. I am flying in upstate
SC. This morning, at 8:15 the top surfaces of the wings on the C1 were
iced significantly, as was the nose and fuselage (tail boom). Outside
air temp was 41*F/Overnight low was 40*F. Plane is tied-down, morning
sun was directly on wing surfaces, no intervening shadows. My lesson
was delayed, of course.

There can be a thermal "dip" right before sunrise, right about at wingtip
height. Duck hunters and deer hunters will confirm (and curse) this
temperature phenomenon - forget what it's called.

41F overnight? 40F at 8:15? And still ice?

So it either go down to 32F at or near your wing, or it was below 32F a
number of feet, maybe many, many feet above your wing? Or your wing was 32F
at some point in the early morning? Wonder what it was?

The temperature of a surface that's radiating heat to a clear night sky
can drop considerably below the ambient air temperature. So it's
possible for frost to form even when the air temperature never gets
down to freezing.

Peter wrote:

The temperature of a surface that's radiating heat to a clear night sky
can drop considerably below the ambient air temperature.

Err... no.

Stefan

Great discription about what a software bug is... I too am a
programmer... errrr sorry... Software Engineer... and you hit the bug
description "nail on the head".. I don't think that the Cirrus issues
are because of bugs in the airplane... It may be "bugs" in the training
process but from what I can tell the airplane (hardware if you will) is
a good design and inherently safe... When I moved up to our Mooney from
the 172's that I flew for 3 years the insurance company required 10
hours dual and 10 hours solo before carrying pax... This seemed like the
minimum when I first started flying the airplane... I wondered if I
wopuld ever get the hang of flying it.. But, low and behold things
started to come together and I am now pretty comfortable flying the plane..

The biggest thing I found when moving up to a faster airplane is you
MUST plan ahead... We are talking many miles ahead especially if you are
fly high.. you may need 40-50 miles to decend to pattern altitude at a
speed where you can get the gear down... If you wait too long and think
you can just "Dive and Drive" you'll never get it slowed down in time..
(been there done that got the t-shirt).

That being said.... What kind of plane are you looking at?

Jon Kraus
PP-ASEL-IA
Mooney 201 4443H

City Dweller wrote:

I have been following the Cirrus crash statistics closely as I was at one
point considering buying one. I ended up ordering another airplane, and I am
sure glad I did.

The sheer number of destroyed airplanes and dead bodies have gone way beyond
the point where you can use the "too-much-of-an airplane-for-the
typical-buyer" argument. When last December I heard a pilot at our flight
school say "they just keep falling out of the skies" I thought of it as
somewhat of an exaggeration, but not anymore. We are barely half-way through
February, and there's been three fatal crashes taking 5 lives already this
year, and 13 total. Yes sir, they do fall out of the skies with a vengeance.

I am a software engineer, and I deal with crashes every day -- software
crashes. Almost every recently released product crashes when put in
production, no matter how hard the programmers and testers pounded on it
during development and QA phases. Software usually crashes because of bugs.
A bug is by definition an error in the code which only surfaces in rare,
unusual circumstances. You can run the software package for days, months and
even years and never encounter the bug, because you were lucky never to
recreate that rare sequence of events in data flow and code execution that
causes the bug to manifest itself and crash the system. However, in a
real-world production environment, with thousands of users, the probability
of that happening increases greatly, and that's when the fun begins.

The reliability of software depends, among other things, on how serious the
programmer is about testing it, and whether he is willing to admit that an
occasional crash of his system maybe the result of a bug in the software,
not a "hardware problem", a common brush-off among my colleagues.

It seems to me that the general attitude of the Cirrus people is just
that -- "it's not a bug in our system, it's how you use it". Well, the grim
statistics does not back that up anymore. Cirrus is buggy, and them bugs
must be fixed before more people die.

-- City Dweller
Post-solo Student Pilot
(soon-to-be airplane owner, NOT Cirrus)

"Happy Dog" wrote:
The more of these Cirrus accidents I read about, the more I'm
convinced that Cirrus has a serious marketing/training problem:

Nobody cares.

Is that why "nobody" responded to the post?

Your opinions are of no interest to the world at large. Do you have
stats to back your claim?

I might ask you the same question.
--
Dan
C172RG at BFM

"Stefan" wrote in message
...
Peter wrote:

The temperature of a surface that's radiating heat to a clear night sky
can drop considerably below the ambient air temperature.

Err... no.

Stefan

Err... yes.
--
Jim in NC

Stefan wrote:

Peter wrote:

The temperature of a surface that's radiating heat to a clear night sky
can drop considerably below the ambient air temperature.

Err... no.

Err ... Yes. The Romans used to make ice in North Africa by taking advantage of
this phenomena.

George Patterson
He who would distinguish what is true from what is false must have an
adequate understanding of truth and falsehood.

That's pretty cool (Pardon the pun ) Where can I read up on that George?

Patrick


"George Patterson" wrote in message
...


Stefan wrote:

Peter wrote:

The temperature of a surface that's radiating heat to a clear night sky
can drop considerably below the ambient air temperature.

Err... no.

Err ... Yes. The Romans used to make ice in North Africa by taking
advantage of
this phenomena.

George Patterson
He who would distinguish what is true from what is false must have an
adequate understanding of truth and falsehood.

W P Dixon wrote:

That's pretty cool (Pardon the pun ) Where can I read up on that George?

I read about it in the 70s and don't remember where; probably a Science Fact
article in Analog or Popular Mechanics. As I recall, the technique is to dig a
hole large enough to keep your water container completely below ground. Cover it
during the day and insulate it (the Romans used straw). Leave it open to the
night sky. It will freeze in a few days. The article said it only works in areas
where the night sky is usually perfectly clear (ie. the desert).

George Patterson
He who would distinguish what is true from what is false must have an
adequate understanding of truth and falsehood.

On Fri, 11 Feb 2005 09:26:18 -0500, "Morgans" wrote:

"Stefan" wrote in message
...
Peter wrote:

The temperature of a surface that's radiating heat to a clear night sky
can drop considerably below the ambient air temperature.

Err... no.

Err... yes.

Let me guess what's going on here.

"Ambient air temperature" means " the current local temperature of the air."
As someone said in another post, this is a fairly imprecise term and
depends on where the measurement is made at an airport.

Heat can be transferred by conduction (two masses in contact), convection
(circulation of gases or liquids), and radiation (infrared rays carry heat
away from the warm mass elsewhere).

Two masses in contact with each other (airplane skin and the air
that contacts it) have got to reach thermal equilibrium, all things
being equal and given sufficent time. Stefan seems to be focused
on this fact--the skin and the layer of air near it have to be at
the same temperature. JSM says, "But that layer of air may
be cooled more than the ambient air because the surface
loses heat not only to the ambient air but also by means of
infrared radiation."

The contrary situation certainly seems to be true: some surfaces
can be way hotter than the ambient air temperature because they
gain heat by "soaking up the sun's rays" (both infrared and visible,
I imagine). The air in contact with the hot surfaces must be in
equilibrium with the hot surface, though the air temperature would
decline to ambient air temperature as you move further away
from the surface.

Or so it seems to me.

Marty