Winter IFR currency vs icing

[tawood]

So this is my first Michigan winter with an instrument rating. I'd like to stay more than just legally current, but I'm concerned about ice. I know I could always take my friend/safety pilot up for some hood time, but I find this very boring compared to actual, which I enjoy/prefer.
The guy I use for a safety pilot has a PA28 like me, but unlike my 700 pilot hours (majority VFR), his flight hours are in the thousands (I think he said close to 10,000) all GA flying, with several thousand in his PA28. He normally impresses me as a very safety conscious pilot. I mentioned to him, in the presence of another old timer (who also has thousands of GA hours), that I'm concerned about winter flight in the clouds and ice. They both laughed, and both said they often fly into (or should I say through) the clouds in winter, in small GA aircraft with next to no anti-ice equipment. They both said it is a matter of getting through thin cloud layers, limiting your exposure, avoiding staying in clouds--especially the tops, etc.
This sounds crazy to me...I've had one encounter with ice while VFR, and I hope to never have an encounter again. My experience with both PIREPS and cloud predictions has shown that knowing cloud thickness is often a guess. Are these guys crazy? Seems like in addition to being crazy, they may also be bending, if not breaking, the rule of flight into known icing...
Or is it just my lack of experience...

 

[AggieMike88]

There are many resources available to you to increase your education about Icing from an aviation viewpoint (versus hockey or baking).

@scottd has some really good videos on his youtube channel and some really good material in his new book and on his primary website, www.avwxworkshops.com.

(Main point here is to learn about the different Icing Weather Products that can show you freezing levels, Probability of Icing, and so forth)​

Googling "Airframe Icing" found many references and content creators I am familiar with and like.

Reviewing the FAA AC 91-74B - Pilot Guide: Flight In Icing Conditions might help you.

Chapter 10 of the FAA's Aviation Weather book, AC 00-06B talks about Icing.

And more if you keep digging.

 

[AggieMike88]

This might also be a good opportunity to learn about the Skew-T Log P diagram. How it's constructed, and how to interpret the information it provides.

It is an excellent tool to determine if there will be very cold clouds along your path of flight that could ice up your aircraft

 

[tawood]

There are many resources available to you to increase your education about Icing from an aviation viewpoint (versus hockey or baking).

@scottd has some really good videos on his youtube channel and some really good material in his new book and on his primary website, www.avwxworkshops.com.

(Main point here is to learn about the different Icing Weather Products that can show you freezing levels, Probability of Icing, and so forth)​

Googling "Airframe Icing" found many references and content creators I am familiar with and like.

Reviewing the FAA AC 91-74B - Pilot Guide: Flight In Icing Conditions might help you.

Chapter 10 of the FAA's Aviation Weather book, AC 00-06B talks about Icing.

And more if you keep digging.

I've read both of those FAA pdfs...both say: avoid 2 degrees to -20 degrees and clouds if you don't have FIKI capability...period. I've also read a good article by AOPA about FIKI and airmets, etc, which would seem to also say avoid clouds during these times....just seems contrary to what these two old timers are saying.

 

[Tantalum]

avoid 2 degrees to -20 degrees and clouds if you don't have FIKI capability...period. I've also read a good article by AOPA about FIKI and airmets, etc, which would seem to also say avoid clouds during these times....just seems contrary to what these two old timers are saying.

I did my IR training in the winter months.. fine, it was San Diego, but we were often around 8K-10K where the OAT was right around this danger zone, say -5 to plus 2.. while there was moisture often, we never actually picked up ice. And of course, stayed out of any clouds with known ice in it and checked pireps, etc. Pitot heat was always on.. and carb heat if we were in the Skyhawk.. for some reason my CFI was against using carb heat in the Piper unless symptoms of ice were noticed

My CFI had around 6K hours.. most of it in non FIKI planes, most of them up north in the Visalia area, and he was conscientious about keeping an eye on the wings and OAT, but.. honestly, the VAST majority of training aircraft (if not all) will not be FIKI.. yet people get their IR ratings and fly in the winter months decently often.

What's odd is, I didn't start routinely getting ice in conditions conducive to ice (-5 to plus 2) until I was in the Cirrus.. there it was almost a guarantee that if you plowed into a cloud anywhere from -5 to plus 3 you'd start getting ice. Perhaps the higher wing loading and faster speeds make that wing more prone to it. But I almost instantly start seeing that little tab fill up with ice

Anyway, stay safe up there.. complacency is dangerous.. trust the old timers, but as a licensed pilot you are acting PIC.. so don't do anything you know is dangerous or illegal


PS.. if you do pickup ice, well now you are in "known icing conditions" and you need to start finding a way out. There was a thread a long time ago on here about a guy in an Arrow who would press on in icing conditions even after he was picking up ice, his excuse was "it was not forecast, no pireps, so it is not known icing" <- which is ridiculous, if you are getting ice then you are in known icing

 

[murphey]

Visible moisture is a good indication of icing. Clouds. Snow. Stuff like that. AggieMike and Tantalum have it right.

 

[jordane93]

Sounds like they’re advocating flight into known icing without the proper equipment. Seems like a good idea to me.

 

[James331]

Another thought is to do 6mo recurrent training (simulator winter plane summer) with a good high time CFII. Take a couple days to go over systems, IFR ops, emergency drills, ice buildup, etc.

Also if it’s near 0 IOAT and your in viz under 1sm, or ANY precip, you’re playing with fire...errr....or rather ice.

 

[flyingcheesehead]

They both laughed, and both said they often fly into (or should I say through) the clouds in winter, in small GA aircraft with next to no anti-ice equipment. They both said it is a matter of getting through thin cloud layers, limiting your exposure, avoiding staying in clouds--especially the tops, etc.
This sounds crazy to me...I've had one encounter with ice while VFR, and I hope to never have an encounter again. My experience with both PIREPS and cloud predictions has shown that knowing cloud thickness is often a guess. Are these guys crazy?

Maybe... But, welcome to the Great Lakes region, where half the pilots park their planes from October through April (and then blast off on a long vacation with their families on their first flight in the spring - ugh), and the other half have done what we can to learn about it and live with it.

@Everskyward posted an article quite a while back that I wish I could find - It was written in collaboration with the people from the NASA Glenn Research Center in Cleveland, the world's foremost experts on icing. One of the big takeaways from that article for me was that even when all of the right conditions are present for icing, 80% of the time it doesn't happen. So, sometimes you'll *expect* it and not get any! There's also plenty of time in the winter where we're too cold for icing, though it can still have a tendency to appear in the top couple hundred feet of a cloud layer due to solar heating.

The real trick is to just expect that there might be ice on any flight, have suitable outs, and execute them immediately if necessary. We have a lot better tools these days for predicting icing (Skew-T, CIP and FIP, etc) that are more reliable than some of the things that were around a decade or more ago. Learn what they are and how to use them, and you'll have a better chance of predicting ice, but you still need to have those outs... And you should have those outs available even if there is no forecast for icing, because the forecasts can be wrong in either direction.

 

[MauleSkinner]

PS.. if you do pickup ice, well now you are in "known icing conditions" and you need to start finding a way out. There was a thread a long time ago on here about a guy in an Arrow who would press on in icing conditions even after he was picking up ice, his excuse was "it was not forecast, no pireps, so it is not known icing" <- which is ridiculous, if you are getting ice then you are in known icing

I would also suggest understanding the FAA’s definition of known Icing...it’s usually far beyond just seeing it on your airplane.

 

[benyflyguy]

I am finishing up my IFR. Checkride pending (yay). I share your concerns and have quite a fear of icing conditions. Probably made worse from all the FAAST/wings cme I’m doing!!
My CFI knows this. We purposely went up last week on an IMC day to do some local approaches to some different fields. While it wasnt forecast as “known icing”. It was the type of day you could find it easily. We found some ice...I’m glad we did.
I learned where to look for it on the plane...
I learned what it looks like.
I learned what to look for in the weather ahead of me to predict it somewhat.
I learned what to do about it, how to shed it.
We talked about what to look for that you have too much and are in trouble.

It was an amazing experience. I still would treat any ice with great concern..I won’t freak out about it. I feel more confidence in what to do and how to take action. It was very relieving to “live” it and talk through it in real time.

If you have a CFI that is experinced in GA and those type of conditions I think it would be a great opportunity to learn a lot about it.

 

[Tantalum]

.it’s usually far beyond just seeing it on your airplan

For sure.. but for the average person flying around, that's a sure fire way to know that you must get out of your current situation

 

[flyingcheesehead]

We purposely went up last week on an IMC day to do some local approaches to some different fields. While it wasnt forecast as “known icing”. It was the type of day you could find it easily. We found some ice...I’m glad we did.
I learned where to look for it on the plane...
I learned what it looks like.
I learned what to look for in the weather ahead of me to predict it somewhat.
I learned what to do about it, how to shed it.
We talked about what to look for that you have too much and are in trouble.

It was an amazing experience. I still would treat any ice with great concern..I won’t freak out about it. I feel more confidence in what to do and how to take action. It was very relieving to “live” it and talk through it in real time.

If you have a CFI that is experinced in GA and those type of conditions I think it would be a great opportunity to learn a lot about it.

This. My first time in ice (luckily, with a CFI!) freaked me the hell out. The CFI was much calmer about it.

I was lucky enough to have a couple more icing encounters with a CFI on board before I ever picked any up on my own. Now, instead of a panic-inducing event, it's just another one of the things that happens when you're flying that causes a change in plans to be executed.

I dunno if @tonycondon is still around these parts, but I've seen him give some absolutely brilliant instruction in ice.

 

[Clip4]

So this is my first Michigan winter with an instrument rating. I'd like to stay more than just legally current, but I'm concerned about ice. I know I could always take my friend/safety pilot up for some hood time, but I find this very boring compared to actual, which I enjoy/prefer.
The guy I use for a safety pilot has a PA28 like me, but unlike my 700 pilot hours (majority VFR), his flight hours are in the thousands (I think he said close to 10,000) all GA flying, with several thousand in his PA28. He normally impresses me as a very safety conscious pilot. I mentioned to him, in the presence of another old timer (who also has thousands of GA hours), that I'm concerned about winter flight in the clouds and ice. They both laughed, and both said they often fly into (or should I say through) the clouds in winter, in small GA aircraft with next to no anti-ice equipment. They both said it is a matter of getting through thin cloud layers, limiting your exposure, avoiding staying in clouds--especially the tops, etc.
This sounds crazy to me...I've had one encounter with ice while VFR, and I hope to never have an encounter again. My experience with both PIREPS and cloud predictions has shown that knowing cloud thickness is often a guess. Are these guys crazy? Seems like in addition to being crazy, they may also be bending, if not breaking, the rule of flight into known icing...
Or is it just my lack of experience...

The Great Lakes region is one on the worst areas for ice in the US.
They are limiting their exposure to stratus (lt-mod rime), a ceiling that allows a safe altitude to level off and acceleration prior to penetrating the cloud, a top that is a short distance in the climb.

Try that stuff with nice wet cumulus (clear ice) off the Great Lakes you are going to be a very unhappy guy.

 

[chemgeek]

The Great Lakes region is one on the worst areas for ice in the US.
They are limiting their exposure to stratus (lt-mod rime), a ceiling that allows a safe altitude to level off and acceleration prior to penetrating the cloud, a top that is a short distance in the climb.

Try that stuff with nice wet cumulus (clear ice) off the Great Lakes you are going to be a very unhappy guy.

Yep. Downwind of Lake Ontario you can pick up 1/4 inch of ice in no time. Worst icing I've ever experienced was climbing up and down through a "thin" lake effect cloud layer during a January IPC. We gave up after two approaches and went home VFR where we also experienced carb icing as well. It really puts a crimp in XC flying November to April in a light single.

 

[TheGolfPilot]

I don't mind flying near or at 0c as long as I know there is assignable altitude below me if I see any ice. I do not see "going up" as an optional escape in a single engine. So much of a hint of ice and I'm out of there. I know people that regularly fly in ice and I just want nothing to do with it. They think I'm a wimp and that is okay. I would be a little more willing to transit through it in a FIKI plane, but still wouldn't want to sit in it. Ice takes pilot "skills" right out of the equation. If the wing doesn't produce lift and the prop doesn't produce thrust, the pilot can no longer control the airplane and becomes a passenger. When the pilot becomes a passenger it usually doesn't end well.

CFI's give people a false sense of security. Being an instructor doesn't make them immune from nature. If ice on the wing or prop of a non fiki single doesn't scare you, you are flirting with disaster and misinformed. On the other hand, that instructor may just be withholding their fear internally to try to keep you calm.

 

[jordane93]

I don't mind flying near or at 0c as long as I know there is assignable altitude below me if I see any ice. I do not see "going up" as an optional escape in a single engine. So much of a hint of ice and I'm out of there. I know people that regularly fly in ice and I just want nothing to do with it. They think I'm a wimp and that is okay. I would be a little more willing to transit through it in a FIKI plane, but still wouldn't want to sit in it. Ice takes pilot "skills" right out of the equation. If the wing doesn't produce lift and the prop doesn't produce thrust, the pilot can no longer control the airplane and becomes a passenger. When the pilot becomes a passenger it usually doesn't end well.

CFI's give people a false sense of security. Being an instructor doesn't make them immune from nature. If ice on the wing or prop of a non fiki single doesn't scare you, you are flirting with disaster and misinformed. On the other hand, that instructor may just be withholding their fear internally to try to keep you calm.

It also shows how far they’re willing to stretch things.

“We’re VFR but we can go through that little cloud. It’s not a big deal.”

“Let’s sneak down a little below minimums to see if we can see the lights.”

“We’re only a little overweight, we can make it.”

You can see how these things can snowball into something bad.

 

[James331]

It also shows how far they’re willing to stretch things.

“We’re VFR but we can go through that little cloud. It’s not a big deal.”

“Let’s sneak down a little below minimums to see if we can see the lights.”

“We’re only a little overweight, we can make it.”

You can see how these things can snowball into something bad.

 

[Palmpilot]

I think this is the Chief Counsel's most recent interpretation of what constitutes "known icing":

https://www.faa.gov/about/office_or...s/2009/bell - (2009) legal interpretation.pdf

Excerpt:

"The FAA does not necessarily consider the mere presence of clouds (which may only contain ice crystals) or other forms of visible moisture at temperatures at or below freezing to be conducive to the formation of known ice or to constitute known icing conditions."
​

So the FAA's definition is not as simple as it used to be. The interpretation letter goes into some detail on the types of factors that pilots need to take into account.

 

[flyingcheesehead]

I don't mind flying near or at 0c as long as I know there is assignable altitude below me if I see any ice. I do not see "going up" as an optional escape in a single engine.

If you're flying cross country (ie, level) into the back of a warm front (ie, the warm side to the cold side), you'd best rethink your position quickly, because the warm air is above you and if you descend, you're going to pick up more ice, not less.

I think this is the Chief Counsel's most recent interpretation of what constitutes "known icing":

https://www.faa.gov/about/office_org/headquarters_offices/agc/practice_areas/regulations/interpretations/data/interps/2009/bell - (2009) legal interpretation.pdf

Excerpt:

"The FAA does not necessarily consider the mere presence of clouds (which may only contain ice crystals) or other forms of visible moisture at temperatures at or below freezing to be conducive to the formation of known ice or to constitute known icing conditions."
​

So the FAA's definition is not as simple as it used to be. The interpretation letter goes into some detail on the types of factors that pilots need to take into account.

Yeah, the previous definition included "high humidity" even if it was CAVU! IE, they could nail you for flight into "known icing" on a perfectly clear day! So, this interpretation is much better, and not really much of a definition. I think they finally realized that predicting ice is a complex thing, and even the experts frequently get it wrong.

 

[sarangan]

The phrase 'known icing' is one of the dumbest things that the FAA invented. We don't talk about flight into 'known thunderstorms', or 'known IMC', or 'known crosswinds'.

One can take the most conservative route and never fly into clouds below freezing temperatures. That's the safest option. Or one could take some educated risks. I am ok to descend or climb through a stratus layer, if the atmosphere is stable, to reach VFR conditions below/above. I would avoid cumulus clouds that are below freezing, especially the top half. I would not attempt prolonged flight in such conditions, or even an instrument approach. In other words, if it is not VFR above and below, then it is a no go for me.

 

[tonycondon]

Yep @flyingcheesehead still lurking around. That was a fun flight with you and Scudwalker. Slightly above freezing in Ames, forecast right at freezing at destination. Started to get a little Ice 10 miles out so flipped a 180 and went back to the warm air. Always have an out.

This. My first time in ice (luckily, with a CFI!) freaked me the hell out. The CFI was much calmer about it.

I was lucky enough to have a couple more icing encounters with a CFI on board before I ever picked any up on my own. Now, instead of a panic-inducing event, it's just another one of the things that happens when you're flying that causes a change in plans to be executed.

I dunno if @tonycondon is still around these parts, but I've seen him give some absolutely brilliant instruction in ice.

 

[iamtheari]

On the other hand, that instructor may just be withholding their fear internally to try to keep you calm.

I thought that this was the #1 skill for CFIs: Appearing calm even though the plane is being flown by someone who is trying to kill them.

for some reason my CFI was against using carb heat in the Piper unless symptoms of ice were noticed

The POH of the PA-28-180 that I learned in explicitly said this. Carb heat only if there are symptoms of carb ice.

About icing...I read an article a while back about the ice research project at UND. They had a jet (Citation, I think) and had to go out looking for icing. They typically ended up over Michigan for that mission. So while I get weather that I figure is high-risk for icing here in North Dakota, the truth is that our winter is typically too cold and dry for clouds to form, so it's blue-sky VFR most of the winter.

Today would be an exception. We had a heat wave that melted off our early snow and today the rain just changed into snow. The Skew-T/Log-P shows this, with clouds from our 100-foot ceiling (2200 MSL) up to about 8,000 MSL and temperatures of -5 up to 0 throughout that range. I think this is what an ice factory looks like:



But I'm really interested to follow this thread, as there are plenty of days when I look at the Skew-T/Log-P and think there is a small chance of icing in a narrow band of altitudes, and then I choose not to fly because wherever I wanted to go isn't worth even the small chance. As always when it comes to flying, I'd like to expand my knowledge so my confidence can follow. (Rather than the other way around, which I suspect is at play in some of those old-time pilots that the OP mentioned, who regularly fly into high-probability icing situations.)

 

[Tantalum]

Carb heat only if there are symptoms of carb ice.

yes, I recall that from the poh as well, but I'm curious the reason as it's a pretty straight similar engine to the Skyhawk.. I had read that the intake tube on the Piper is less conducive to ice, and that there's no air filter on the carb heat so its use is discouraged unless really needed

 

[Palmpilot]

yes, I recall that from the poh as well, but I'm curious the reason as it's a pretty straight similar engine to the Skyhawk.. I had read that the intake tube on the Piper is less conducive to ice, and that there's no air filter on the carb heat so its use is discouraged unless really needed

I thought the unfiltered air was only an issue for fuel-injected engines that have an alternate air intake instead of carb heat.

 

[tawood]

I thought that this was the #1 skill for CFIs: Appearing calm even though the plane is being flown by someone who is trying to kill them.


The POH of the PA-28-180 that I learned in explicitly said this. Carb heat only if there are symptoms of carb ice.

About icing...I read an article a while back about the ice research project at UND. They had a jet (Citation, I think) and had to go out looking for icing. They typically ended up over Michigan for that mission. So while I get weather that I figure is high-risk for icing here in North Dakota, the truth is that our winter is typically too cold and dry for clouds to form, so it's blue-sky VFR most of the winter.

Today would be an exception. We had a heat wave that melted off our early snow and today the rain just changed into snow. The Skew-T/Log-P shows this, with clouds from our 100-foot ceiling (2200 MSL) up to about 8,000 MSL and temperatures of -5 up to 0 throughout that range. I think this is what an ice factory looks like:

View attachment 69226

But I'm really interested to follow this thread, as there are plenty of days when I look at the Skew-T/Log-P and think there is a small chance of icing in a narrow band of altitudes, and then I choose not to fly because wherever I wanted to go isn't worth even the small chance. As always when it comes to flying, I'd like to expand my knowledge so my confidence can follow. (Rather than the other way around, which I suspect is at play in some of those old-time pilots that the OP mentioned, who regularly fly into high-probability icing situations.)

Ok, so I've studied up on my Skew-T/Log-P, and I'd like to try using them...where are you getting your sounding information? I've tried several sources online from google, but so far, they aren't working too well.

 

[iamtheari]

Ok, so I've studied up on my Skew-T/Log-P, and I'd like to try using them...where are you getting your sounding information? I've tried several sources online from google, but so far, they aren't working too well.

https://rucsoundings.noaa.gov/

Merry Christmas. Except you'll play with this a lot longer than you would if I gave you a train set.

To get started, just load the page, put in your airport identifier in the "Site(s)" box, and click Interactive Plot. No other changes needed for basic use.

 

[GeorgeC]

Ok, so I've studied up on my Skew-T/Log-P, and I'd like to try using them...where are you getting your sounding information? I've tried several sources online from google, but so far, they aren't working too well.

You can also drill into the Forecast Models section of tropicaltidbits.com, click and drag out a rectangle, and get a sounding averaged over the area you selected.

 

[flyingcheesehead]

About icing...I read an article a while back about the ice research project at UND. They had a jet (Citation, I think) and had to go out looking for icing. They typically ended up over Michigan for that mission. So while I get weather that I figure is high-risk for icing here in North Dakota, the truth is that our winter is typically too cold and dry for clouds to form, so it's blue-sky VFR most of the winter.

The Great Lakes most certainly cause a lot of weather, including icing. It's especially bad earlier in the winter, since the lakes are still near their warmest temps (peak is generally in October) and the air that would otherwise be cooler and drier gets cold and wet near the lakes and anywhere downwind of them. This is what causes lake-effect snow as well. Michigan can get it pretty bad, but places like Cleveland and Buffalo do as well. Buffalo may be the worst...

I thought the unfiltered air was only an issue for fuel-injected engines that have an alternate air intake instead of carb heat.

Carb heat air is also unfiltered.

I've heard some speculation that placement of the air intake relative to other things inside the cowl can make a difference. It's also worth noting that there are times where it's a bad idea to use carb heat in a Cessna, since there are certain temperature/humidity conditions where having carb heat on can actually *cause* ice instead of preventing it. Knowing the chart below is one way of dealing with it, but IMO a carb temp probe makes things much easier.

 

[Ted]

@Everskyward posted an article quite a while back that I wish I could find - It was written in collaboration with the people from the NASA Glenn Research Center in Cleveland, the world's foremost experts on icing. One of the big takeaways from that article for me was that even when all of the right conditions are present for icing, 80% of the time it doesn't happen. So, sometimes you'll *expect* it and not get any! There's also plenty of time in the winter where we're too cold for icing, though it can still have a tendency to appear in the top couple hundred feet of a cloud layer due to solar heating.

I have no idea where they came up with that statistic, because my experience has been the exact opposite. I get icing virtually 100% of the time that I'm in a cloud with it below freezing, at least until it's -20C or colder... then maybe it's only 50% of the time.

My short answer: if you don't have de-ice, stay out of all clouds that are below freezing. If you have my luck, you'll get icing. However sometimes weather can do funny things temperature wise - I've had it be 20F on the ground and 50F at 6,000 ft, go figure. That's where the Skew-Ts can be very helpful.

 

[Palmpilot]

Carb heat air is also unfiltered.

Aha, so it is. I never actually looked at a diagram before.

 

[flyingcheesehead]

I have no idea where they came up with that statistic, because my experience has been the exact opposite. I get icing virtually 100% of the time that I'm in a cloud with it below freezing, at least until it's -20C or colder... then maybe it's only 50% of the time.

Interesting. In my experience they're pretty much on the money. I've even picked up ice descending through the same layer I climbed through ice-free only 10 or so minutes before, and I don't think I've ever gotten ice below -20C.

Maybe you're an ice magnet, @Ted DuPuis.

 

[bluesky74656]

I was thinking of trying to get a few approaches in tomorrow, but the forecast looks frosty in northern Ohio.

 

[Stephen Shore]

One thing that you MUST determine before fly with ANY chance of ice - is your windscreen defroster capable of clearing it off of your windscreen?

I have picked up ice and had to land - and the first time the most worrisome part was how fast it accumulated on my windshield. Luckily, my defroster worked great and cleared it off.

Now the obvious question is if you are flying in IMC why would it matter about not being able to see out of your windshield? Real simple - at some point on your approach you will need to see out of that windshield! Just because you descend out of the clouds to land does not mean the airplane sheds the ice!

Make sure your defroster works before you fly this winter.

 

[tawood]

One thing that you MUST determine before fly with ANY chance of ice - is your windscreen defroster capable of clearing it off of your windscreen?

I have picked up ice and had to land - and the first time the most worrisome part was how fast it accumulated on my windshield. Luckily, my defroster worked great and cleared it off.

Now the obvious question is if you are flying in IMC why would it matter about not being able to see out of your windshield? Real simple - at some point on your approach you will need to see out of that windshield! Just because you descend out of the clouds to land does not mean the airplane sheds the ice!

Make sure your defroster works before you fly this winter.

As I said above, I've had one encounter with ice while VFR...defroster didn't really work...funny thing is, the defroster air comes out so hot that it will burn your hand, yet it doesn't really melt the ice on the windshield:

 

[GRG55]

Interesting. In my experience they're pretty much on the money. I've even picked up ice descending through the same layer I climbed through ice-free only 10 or so minutes before, and I don't think I've ever gotten ice below -20C.

Maybe you're an ice magnet, @Ted DuPuis.

I think he must be.
Out here in the west where I live ice at -20 is virtually unheard of.

As I said above, I've had one encounter with ice while VFR...defroster didn't really work...funny thing is, the defroster air comes out so hot that it will burn your hand, yet it doesn't really melt the ice on the windshield:

View attachment 69246

To melt the ice requires enough heat be conducted through the thickness of the plexiglass windshield to overcome the convective heat loss from the air flowing over the outside of it. At the speeds light aircraft fly there's a lot of air flowing over that windshield, and difficult to overcome the heat loss if the OAT is much below freezing.

One Piper I used to rent early on had a very hot defroster outlet temp. Somebody put it on full blast and softened the plastic immediately above the defroster outlets, distorting the windshields on both sides.

A windshield plate like the one in the pic below works better, but don't leave it on after landing. If there's not enough convective airflow across them they can overheat and toast themselves. A very expensive mistake. Note the loss of paint on the nose of the Seneca from ice being shed from the props. I've seen Barons with the sides of the nose seriously dented from that. Piper twins seem more robust and the damage is generally only cosmetic. My Aztec came from the factory with fibreglass ice shields installed in that area of the nose.

 

[SbestCFII]

Check your winds aloft for temp inversions on days with a decent CIG. What you'll want to look for are temps above freezing in the clouds and you can fly in those without too much worry, just monitor the OAT and PIREPs. For example, I was training a student a few years ago with an inversion. The temp on the ground was 37F, and dropped to 0F around 2000' then started getting warmer as we climbed. No precip. and no ice issues during the flight, except for just a little light rime and a little windscreen ice descending through 2000' on the approach, and that melted off quickly on the missed climb back above 2000. If you look for the right conditions it can be done safely, just stay close to the airport and keep a low threshold for landing. Snow isn't really an issue...mostly a visibility issue, just remember to turn on pitot heat.

 

[GeorgeC]

It's actually not averaged. It's a point forecast from the closest model grid point.

If you drag a large enough rectangle, it says "Surface pressure varies too much (125 hPa, limit is 100 hPa) within the requested domain to make an accurate mean sounding".

 

[texasclouds]

take an old salt up there with you.

 

[iamtheari]

What makes you believe the tops are at 8,000 feet here?

I probably should have said "at least 8,000 feet." They could well be higher. But the temperature and dewpoint begin to diverge at around that level. I don't experiment enough in soundings that look like that to have any empirical data of my own.