What I learned about Icing today...

[TaterSalad]

To answer the questions above...................I would imagine he asked for higher, because the cloud tops were reported as 10k'. Get out of the clouds, ice stops accumulating. Remember, it takes visible moisture to get ice. According to his post, the freezing level was reported at 9k-10k, however at 7k' he was getting ice. He also said the cloud layer was 2k'-10k' (I believe). So, the freezing level is already lower than predicted, who knows how much lower it actually is? And with visible moisture all the way down to 2k', potentially you could be in icing conditions down to a level very close to the earth, with very few options at that point. Make sense?

 

[MikeD]

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To answer the questions above...................I would imagine he asked for higher, because the cloud tops were reported as 10k'. Get out of the clouds, ice stops accumulating. Remember, it takes visible moisture to get ice. According to his post, the freezing level was reported at 9k-10k, however at 7k' he was getting ice. He also said the cloud layer was 2k'-10k' (I believe). So, the freezing level is already lower than predicted, who knows how much lower it actually is? And with visible moisture all the way down to 2k', potentially you could be in icing conditions down to a level very close to the earth, with very few options at that point. Make sense?

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To add....if you're picking up ice, you'll generally have freezing rain/freezing drizzle below.

 

[dingo222]

the clouds were topped out at 10, and I could see the sun poking through. I may have been able to get out of them by 9k or so.

THe second reason was that I wasn't sure where the ice started, so even as I went back down, i was still picking up ice. My goal was to get out of it, up or down. Up was just easier to get to at that point.

The goal was to get out of the visible moisture and into the sun to hear that great sound of ice flaking off and hitting the airplane!

 

[EatSleepFly]

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I must admit that I don't have any serious experience with ice, but my understanding is this:

Ice generally occurs in layers a few thousand feet thick. Either climbing or decending usually gets you out of it. Down lower it's warm enough to keep ice from freezing and up higher it's cold enough that the clouds are already frozen, so it doesn't stick to your wings.

However, going higher is generally better than going lower because you're giving yourself more room if it keeps accumulating. If you descend and can't get out of it, now you're down at the MEAs with a load of ice, so you don't have the performance to climb, and don't have the terrain clearance to descend. If you had climbed to begin with, but it kept accumulating, at least you'd have more time to turn around and more time to descend. Also, remember that the forecasts are just best estimates....obviously they got unforecast ice, so they couldn't really trust the forecast anymore.

I'm sure the freight pilots like EatSleepFly could give you a more experienced voice on this. How close did my answer get?

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Sounds good to me. Except I wouldn't say that going lower will necessarily be warm enough to keep you out of ice. This time of year, sure, but not in the winter. You'll get ice on the ground in the winter. It's almost always better to climb as high as you can, basically for all the reasons you said. Plus, in the Caravan, it doesn't shed ice all that great unless you're doing above 160 kts., which if you have ice can only be done in a descent, really. So going high gives you the opportunity to blow it off good once or twice as you're descending. Although, latest "procedure" for the 'Van is to blow the boots once they have any accumulation of ice. Not sure how much I agree with that, but whoever came up with that has more experience than me, I'm sure.

Icing is difficult to predict/forecast. I've gotten none where I thought I'd get loaded, and I've turned into a popsicle where I didn't think it'd be so bad.

Here's to hoping I will be out of the 'Van and hauling boxes in something else before icing season gets into full swing.

 

[NJA_Capt]

the clouds were topped out at 10, and I could see the sun poking through. I may have been able to get out of them by 9k or so.

You'll see soon enough how misleading this can be. I have felt the same way, "just another 1000 ft should do it." Then, 20,000 ft later.... "are we ever going to get above this?"

Up was just easier to get to at that point.

Word of caution: Ice usually build faster near the tops.

1) +10 deg C or below:Be careful and stay out of the clouds.
2) Ice not only disrupts airflow, it adds weight.

 

[dingo222]

icing

weight was my issue. SoCAl held me at 7k forever, and it just piled on. THe archer isn't the superstud single of the world, lol. I agree with the idea of not going higher either. The reason that i asked was that the tops report was about 15 mins old, and i could see the light coming through the clouds. I was looking for an out. I should have never gone in! Even if I got above it, I still would have had to come back down through it. Sort of a no win.

Moral: Don't trust wx reports as truth, and watch your AZZ!