Icing (and not the kind you put on cake)

I was wondering if anyone new if you could pick up ice in a cloud made up of just ice crystals? Most clouds contain supercooled water droplets waiting to cling and freeze to the leading edges of your aircraft. But what if it is cold enough for ice crystals to be present and not droplets?

What about snow? Can you run into problems if you are flying through a moderate snowfall?

[djschaut]

Scott,

A topic which will get numerous responses, to be sure.

At work, one of my fellow employees--a non-pilot--made an astute observation. She said 'the airlines have fewer delays in the wintertime from weather.' Well, there are generally fewer problems flying in snow than through thunderclouds or rain.

My instructor used to say that ice could form under any conditions, listen to the radio for it. It's hard to predict. Naturally, the more moisture in the air--combined with cold temperatures (always cold at altitude)--the greater the chance of icing.

Even if there isn't much moisture in the air, you can collect ice. Your wing is supercooled from its airspeed. Also, the higher you fly, the colder the OAT. It's 40 below at FL200.

I think you're much more likely to collect ice--or even snow on your windscreen at slow approach speeds--if you're flying through heavy, wet snow. However, if you're flying through dry powder, no ice should collect at all. I've taken off and landed at Rocky Mountain airports where the wingtips just clear the snow, and the dry snow we get up here doesn't accumulate on the wings. Icing is worse during the late fall and spring--or summer during thunderstorm season. After the dry powder starts falling, you're home free. I've flown IMC in dry powder for hours--at night--with no accumulation. It's actually quite peaceful and calm. Your strobes reflect off the snowflakes.

But those heavy snow clouds closer to sea level are another story, and I've been fortunate not to have to encounter them.

I think that if you hear any PIREPS of icing--rime or otherwise--think twice about flying that direction. If the commercial boys are collecting ice enough to report it, it's significant. If a small GA pilot reports some slight ice collection, well--maybe he's never seen it before.

Then there's the article by a pilot in one of the magazines awhile back who landed in Ohio carrying four inches of ice on the leading edge of his wings, with the controls faltering and control surfaces heavy--who heaved a great sigh when the wheels hit the runway.

I've owned planes equipped with 'known ice' capability, and still avoided it at all costs. I don't need a plane with boots, because I'll never be in a situation where I need them.

If ice slowly accumulates to a half inch or so and then stops--without affecting control surfaces--no worries. But if you get a rapid accumulation and conditions ahead are worse, I think a 180 degree turn is in order to better conditions. One time, with a 'known ice' airplane. After accumulating some ice on my boots once, with worse conditions ahead, I even landed and waited out the night in an FBO. Enough of that. The people with me appreciated it, too. Who knows when you aren't saving all of your lives.

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DJSchaut

[BAYALON]

As there are ice crystals, the temp. is below the freezing point therefore you will not pick ice unless it is a mix cloud made of droplets and ice crystals. I have flown through dry snow and loved it. If you fly through wet snow you probably will pick ice.