Apparently Iced Up

I'm looking for some advice whether I was too onservative he

I recenly flew a VFR flight from Billings, MT to Bozeman, MT. About
40 miles east of Bozeman I decided that I needed to delare IFR and
filed for an Ifr clearance into BZN in order to descend through a 2500
ft cloud layer. I got the clearance into BZN, and landed without
incident.

Later that evening I went to the plane (C172/180) to return to BIL
and found a very thin layer of ice (about 5 or 6 pages of paper thick)
on all the leading edges of my plane. It was dark, about 10pm, and I
elected to stay the night. The night was patchy clouds, but mostly
clear. I had to clear a 9000 foot ridge from a 4500 foot airport,
which the plane was easily capable of doing in normal circumstances.

The ice, and slight frost, on the airplane caused me stay. As I have
never really tried to fly with a slight layer of frost or ice, I
stayed; but I wonder if I was too cautious. It would have been very
convenient for me and my passengers to go. Here's my question: just
how much ice/frost is too much? Would the ice/frost probably have
sublimated on climb out?

What is "too cautious"?
You were correct;
Blue skies.

H.

H. Adam Stevens
CPA S&MEL IA
solo 1967


"smackey" wrote in message
m...
I'm looking for some advice whether I was too onservative he

I recenly flew a VFR flight from Billings, MT to Bozeman, MT. About
40 miles east of Bozeman I decided that I needed to delare IFR and
filed for an Ifr clearance into BZN in order to descend through a 2500
ft cloud layer. I got the clearance into BZN, and landed without
incident.

Later that evening I went to the plane (C172/180) to return to BIL
and found a very thin layer of ice (about 5 or 6 pages of paper thick)
on all the leading edges of my plane. It was dark, about 10pm, and I
elected to stay the night. The night was patchy clouds, but mostly
clear. I had to clear a 9000 foot ridge from a 4500 foot airport,
which the plane was easily capable of doing in normal circumstances.

The ice, and slight frost, on the airplane caused me stay. As I have
never really tried to fly with a slight layer of frost or ice, I
stayed; but I wonder if I was too cautious. It would have been very
convenient for me and my passengers to go. Here's my question: just
how much ice/frost is too much? Would the ice/frost probably have
sublimated on climb out?

"smackey" wrote in message
m

I'm looking for some advice whether I was too conservative he

I agree with Adam Stevens on this one. "Conservative" is a relative term.
Make the safety decisions that make you comfortable. Nobody else can make
those for you.

--
John T
http://tknowlogy.com/TknoFlyer
http://www.pocketgear.com/products_s...veloperid=4415
____________________

Would the ice/frost probably have
sublimated on climb out?

you would have looked pretty dumb if it hadn't
There is only one choice - and that is the safe one.

--

Tony Roberts
PP-ASEL
VFR OTT
Night
Almost Instrument
Cessna 172H C-GICE

You did the right thing to stay for better conditions. You could have gone,
and with a lowered probability been just fine. But your risk level would
have increased, and everything one does in aviation should be to reduce the
risk level. Especially when still on the ground where the decision is easy
and convenient to make.

Ice takes quite some time to sublimate and can not be counted on as a risk
reducer. A thin layer can last for hours.

Karl
ATP ETC

On 25 Dec 2003 18:23:01 -0800, (smackey) wrote:

Here's my question: just how much ice/frost is too much?

Although some talk about polishing it smooth, any amount will change your
air foil and decrease your lift. How much of a test pilot do you want to
be?

Would the ice/frost probably have sublimated on climb out?

Maybe in the post-crash fire?

----------------

I would have either gotten the frost/ice off the a/c, or stayed the night.

RMOAS of a fellow who has a Bonanza. He had a barely visible line of snow
on the leading edge of the wing. It did NOT blow off during the takeoff
roll, and he barely made it off the ground. He was able to successfully
return to the airport, but it made for one of those "never again" stories.


Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

never really tried to fly with a slight layer of frost or ice, I
stayed; but I wonder if I was too cautious.

Never...you did the right thing

It would have been very convenient for me and my passengers to go.

It wouldn't have been so convenient to become a landmark in the side of a
mountain....

Here's my question: just
how much ice/frost is too much?

Any ice/frost is too much unless you want to be considered a test-pilot.
The challenge here is at what point do you call "uncle"... A little frost
probably would not be of great concern...but how about some frost and a
little ice....the ice is smooth, clear and only on the leading edges....etc
etc etc

In my opinion this could have been a recipe for disaster. You were in a
hurry to get home...at night...in the mountains...with airframe ice. Most
accidents are a series of events and/or poor decisions. Deep down you knew
the right answer, and heeded the caution your gut was telling you.... Your
passengers owe you a debt of gratitude.

smackey wrote:
I'm looking for some advice whether I was too onservative he

I recenly flew a VFR flight from Billings, MT to Bozeman, MT. About
40 miles east of Bozeman I decided that I needed to delare IFR and
filed for an Ifr clearance into BZN in order to descend through a 2500
ft cloud layer. I got the clearance into BZN, and landed without
incident.

Later that evening I went to the plane (C172/180) to return to BIL

Would that have been the old "Lynch 145"? If so that was one of my
favorite 172's. Lots of power.

Newps wrote in message news:YBOGb.202440$_M.905032@attbi_s54...

Would that have been the old "Lynch 145"? If so that was one of my
favorite 172's. Lots of power.

Nope. Bought mine in AZ in 1999.

Steve M
N739AJ

Even small amounts of frost can dramatically increase drag while reducing
lift. The comments about test pilot aside, there is no way that frost is
going to improve the performance of your airplane. At the very least you
will need more runway, have a reduced payload, climb more slowly, and have
your weight and balance thrown out of kilter. Your margin for error is
greatly reduced.

Now, add to that the factors of night, that ridge, possibly being tired at
the end of the day. I would hope that under the same circumstances I would
have the presence of mind to make the same decision you did.