Winter flying and icing

4RNB

Line Up and Wait
PoA Supporter
Joined
May 24, 2016
Messages
961
Display Name

Display name:
4RNB
Most of my flying has been in VFR conditions, some actual IFR as a student, but all in warmer temperatures. I'd like to go visit family, landing at an airport SW NY (KJHW). Home is eastern NC. Yesterday I did some planning for a potential flight, route of flight if IFR would require 6000 feet, 8000 gives me better height over some mountains. Pireps yesterday reported some light icing. I'd like to not experience icing, and want to bounce off ideas, receive input and thus better clarity on how to stay safe. IFR equipped C172

My thoughts:
1. No night takeoff or landings due to inability to sufficiently avoid clouds and thus moisture.
2. Avoiding visible moisture (clouds) at cooler cruise altitudes will minimize icing.
3. If I can adequately determine cloud layers, I'm thinking to be willing to penetrate through broken layers for VFR on top (and beneath) conditions, especially at lower levels.
4. For a four hour trip, the middle two hours require more altitude.
5. Basically, I want to have mostly VFR conditions.
6. Icing is unlikely to form "out of thin air", if VFR. Clear air = minimal moisture concerns, even if sub freezing temperatures exist.
7. Middle of the day flying better as temperature dew point spread will be more favorable.

Feedback? Thoughts? Thanks.
 
Do you have ADSB weather and traffic in?

Foreflight premium has the clouds tops level.

Start slow with something VFR on the ground and fly in IMC en route, then you can add more challenges as your skills and experience grow.

If you have ice buildup (you need to visibly look at your wings), then you need to climb above the clouds to allow the sun to melt it off or land. Report the issue to ATC, do not delay. You are not supposed to fly in known icing conditions in a C172 either. Clouds + negative temps (even 2C can have icing so don’t be stuck on 0C) at altitude = icing

I wouldn’t be stuck on middle of the day, most people prefer early morning, it just depends on the weather.

For a 4 hour flight you’d be at altitude for most of the flight. Not sure what is meant by 2 hours ? Make a plan that works with weather, aircraft performance, and winds aloft.
 
You won’t pick up icing in VFR unless there’s rain above that freezes at your altitude. Temp inversions (esp winter warm fronts) can be either friend or foe). I’ve flown IMC in a cold winter morning because where the clouds were it was well above freezing. Study weather and start to learn about weather tools (Skew-T for example).

edit: and always have an out
 
Do you have ADSB weather and traffic in?

Foreflight premium has the clouds tops level.

Start slow with something VFR on the ground and fly in IMC en route, then you can add more challenges as your skills and experience grow.

If you have ice buildup (you need to visibly look at your wings), then you need to climb above the clouds to allow the sun to melt it off or land. Report the issue to ATC, do not delay. You are not supposed to fly in known icing conditions in a C172 either. Clouds + negative temps (even 2C can have icing so don’t be stuck on 0C) at altitude = icing

I wouldn’t be stuck on middle of the day, most people prefer early morning, it just depends on the weather.

For a 4 hour flight you’d be at altitude for most of the flight. Not sure what is meant by 2 hours ? Make a plan that works with weather, aircraft performance, and winds aloft.

Yes, have ADSB. Cloud tops yes, that is why I'm not flying...
I'm not looking to add challenges, looking to avoid ice.
Middle of the flight requires higher altitude.
 
Yes, have ADSB. Cloud tops yes, that is why I'm not flying...
I'm not looking to add challenges, looking to avoid ice.
Middle of the flight requires higher altitude.
To avoid ice, fly VFR in the winter months. That’s the simplest answer.
 
Known icing is not the same as forecast icing or even totally-obvious predictable icing. So you can fly into an icing AIRMET, but don't fly straight through an icing PIREP. The key is to be smart about the weather information available to you, including Skew-T/Log-P charts that will give you a better idea of where the ice may be and how to get out of it if you guess wrong. Then you can go and fly and learn in a somewhat controlled environment.

The basic rule is that you can't pick up ice unless you are in visible moisture (cloud or rain) and the temperature is at or below 0C. But that does not mean you will always get ice whenever you are in a cloud and it's below 0C. Generally, avoid clouds and rain when the temperature is between -20C and +5C. Below -20C if you find a cloud it will probably be ice crystals and snow, rather than moisture. Above +5C it is less likely to suddenly drop on you.

Beyond that, here are a few tips I found helpful when starting out in all-season IFR travel. (My mission includes flying out of the frigid north to escape winter, so all seasons are fair game even if all weather is not.) Know the difference between stratus and cumulus clouds and how to escape ice in both. Try to avoid flying when the ceiling is below the minimum IFR altitude on your route, because it takes away the "rough but no ice" escape route beneath the clouds. Keep a flashlight handy to look at the wings at night. Pay attention to your airplane's performance, especially if you're using an autopilot. I like to bug the airspeed I'm cruising at so I get a visual indication of when I'm going slower to maintain altitude, which can mean that the plane is struggling with icing. When in doubt, turn off the autopilot so you are consciously aware of trim changes. Be aware that the propeller is also an airfoil susceptible to icing and its performance can degrade due to ice that you can't see.

If you have any kind of ice-related equipment, know how and when to use it. That includes pitot heat. (My rule is that it's on anytime I am going into visible moisture, at any temperature. Cheap insurance against the airspeed indicator lying to me.)

Going back to the definition of "known icing," I look at it like Schroedinger's cat. Whether or not there is ice in the forecast, if you pick up ice, that cat is dead and you are in "known icing." Take immediate action, not just "prompt" action like some might suggest. Report it to ATC and get a different altitude or direction of flight. If you can't get what you need from ATC, then take it on your own. Known icing is either an emergency or soon to become one unless you exercise your PIC authority to get out of it. I have had that conversation with ATC and I promise you that it's not a difficult conversation at all.

In my case, I was picking up ice at 11,000 somewhere over Wyoming and requested wrong-direction 12,000, which they gave me and which got me out of the ice. They offered 13,000 if I needed it, but I didn't want to dig out the oxygen tank too soon so I waited. They also told me that I would lose radio contact for a bit and gave me a frequency to try after 20 minutes or so. In the radio dead zone, the ice came up to 12,000 so I needed that 13,000 feet and neither frequency was responding. I transmitted, "we are leaving 12,000 for 13,000 due to icing," then when I got in touch with the next controller I checked in, "assigned 12,000, level 13,000." The response was basically "say why you left your assigned altitude," my answer was "we were picking up ice," and ATC said, "roger, maintain 13,000." No phone number, no follow-up, just a very friendly controller who was as happy as I was that I was shedding ice at the wrong altitude rather than falling out of the right one.

In my experience, spring and fall are worse for flying than winter. But you can get icing on the 4th of July if you know where to look for it. All IFR pilots should study and respect ice, so they can avoid it without simply avoiding the skies altogether. I still prefer to fly over the clouds in an icing AIRMET than to drive on the icy roads beneath them.
 
You won’t pick up icing in VFR unless there’s rain above that freezes at your altitude. Temp inversions (esp winter warm fronts) can be either friend or foe). I’ve flown IMC in a cold winter morning because where the clouds were it was well above freezing. Study weather and start to learn about weather tools (Skew-T for example).

edit: and always have an out
I'm curious, why would you use Skew-T when there are websites like Windy available? I find Windy invaluable all year round, but especially in winter months. The free version is incredibly powerful, and for $20/year, the premium version gives you even finer granularity.
 
Pireps of light ice is known ice. Not legal to fly through if you start picking it up, meaning you could fly through it and not get anything, but if you fly through it and need to deviate with a call to ATC, you could be in trouble. Or it could kill you. Also remember a light ice report from an A-320 could mean worse ice for you.

Stay away from ice. Bad juju. Not a good idea to be expanding your envelope near known icing in a 172. I fly a Cirrus with FIKI, it gives you a little more leeway, but not much.
 
I live/fly ifr in Michigan…we have ice potential 6 months out of the year. As others have said, small planes and ice do not mix, PERIOD. Fly VFR or don’t go if it’s below 34 degrees in clouds at altitude.
 
I'm curious, why would you use Skew-T when there are websites like Windy available? I find Windy invaluable all year round, but especially in winter months. The free version is incredibly powerful, and for $20/year, the premium version gives you even finer granularity.

Wow! I'd seen "Missionary Bush Pilot" use this in PNG, never really looked at it before. The webcam feature seems invaluable for the stuff I am looking at for this flight!
70,000 cams linked, gives preview on map
I think I need to sign up.
Thanks.
 
Having flown in the lee of the Upstate NY lakes for over 30 years, I'll be short - a 172 is not enough airplane to use if there's any chance putting ice on the airframe. Not enough power, and no variable pitch prop, so no means at all of clearing an icing prop, which is the most important thing to keep clean.

With more power, if you can maintain say 1000 fpm, getting on top at 6-9k in winter can lead to sunshine and smooth sailing. But a 172 is in the 500 fpm class with lots of dangly bits. Plus those that do that sort of thing have accumulated years of experience looking at the winds, the kinds and color of the clouds, and their own history to know if it's doable or not - it's very rural there, so local icing reports can be sparse, as is true over much of your route.

Fly VFR from now though April. Especially now through about Jan 1 as the lakes are still warm and will fill the clouds with moisture. After Jan 1 through about mid-march things improve as the lakes have cooled or frozen, but it still can surprise you.
 
I'm curious, why would you use Skew-T when there are websites like Windy available? I find Windy invaluable all year round, but especially in winter months. The free version is incredibly powerful, and for $20/year, the premium version gives you even finer granularity.

aviationweather.gov has a very nice ice forecast plot, which is derived from many factors, not just skew-T data. Plus its free.
 
I'm curious, why would you use Skew-T when there are websites like Windy available? I find Windy invaluable all year round, but especially in winter months. The free version is incredibly powerful, and for $20/year, the premium version gives you even finer granularity.
Skew-T/Log-P plots give you temperature and dewpoint plotted against altitude, which a trained eye will translate into altitudes where you can expect smooth or rough air, clouds or clear, and ice or water. There are other presentations of the same data, but they all give you a top-down view that hides the vertical dimension. They show the horizontal dimensions much better, so they are also very useful for planning an actual flight rather than just showing what things are like above one point on the ground as the Skew-T/Log-P does. Being able to read these things gives you another tool to make a safe but not overly cautious IFR go/no-go decision.
 
Last edited:
Skew-T/Log-P plots give you temperature and dewpoint plotted against altitude, which a trained eye will translate into altitudes where he can expect smooth or rough air, clouds or clear, and ice or water.
While I agree, the OP isn't likely to pick up the skills to clearly understand the implications of a Skew-T plot by the time he flies. Viewing Windy and other online resources along with using weather briefings and PIREPS will probably provide better information to him.
 
Having flown in the lee of the Upstate NY lakes for over 30 years, I'll be short - a 172 is not enough airplane to use if there's any chance putting ice on the airframe. Not enough power, and no variable pitch prop, so no means at all of clearing an icing prop, which is the most important thing to keep clean.

With more power, if you can maintain say 1000 fpm, getting on top at 6-9k in winter can lead to sunshine and smooth sailing. But a 172 is in the 500 fpm class with lots of dangly bits. Plus those that do that sort of thing have accumulated years of experience looking at the winds, the kinds and color of the clouds, and their own history to know if it's doable or not - it's very rural there, so local icing reports can be sparse, as is true over much of your route.

Fly VFR from now though April. Especially now through about Jan 1 as the lakes are still warm and will fill the clouds with moisture. After Jan 1 through about mid-march things improve as the lakes have cooled or frozen, but it still can surprise you.
How does a variable pitch propeller help with icing ? What actions would you take?

Anyone experienced icing? How much time did you have to escape?

Also someone mentioned flying into an icing airmet is ok but not into a pirep of icing. Is that the only thing that is classified as FIKI for legal purposes?
 
While I agree, the OP isn't likely to pick up the skills to clearly understand the implications of a Skew-T plot by the time he flies. Viewing Windy and other online resources along with using weather briefings and PIREPS will probably provide better information to him.
I figure, if we can get him through one fall/winter IFR trip without incident, he'll turn into the rest of us who want to go every week and then he'll have all the time and reason in the world to work on his post-doctorate flight planning education, starting with the Skew-T. :)
 
FYI, the lee of the Great Lakes produces lake effect clouds that can produce prodigious amounts of icing in a short period. Between Nov 1 - April 15 icing in and around Central and Western NY can often be a no-go. While I have made some IFR flights in winter or transitional seasons in my AA-5, I need to be sure of outs in case of icing. That usually means adequate VFR below cloud bases, and confidence that I can safely get and stay above cloud tops enroute. A typical lazy lake-effect cloud deck will top out at 6000-9000 MSL, and will eventually dissipate if you are flying away from the lakes. But it can be a crap shoot. You either climb up through at -2C and get no icing, or you get loaded up with 1/4" or more in minutes. The latter is no place to be in a light single with no ice protection. Been there done that just doing an IPC. That was a short day.

Basically, in winter in Central and Western NY if you are in cloud, you are likely going to pick up ice. I don't plan many trips that don't require a large amount of flexibility in the winter months. There are days where you just can't fly below 10,000 MSL in a light single without getting into trouble. Lake effect weather has already started this fall. As I sit in my "sun" room, I'm looking at 4800 BKN with tops at FL 290 with a brisk westerly breeze. The freezing level is near the cloud bases. Today's lake effect clouds are angry. The last few days they were topping out at 8000 MSL or so with bases around 3000-5000 MSL, more "typical" of benign days.
 
I live/fly ifr in Michigan…we have ice potential 6 months out of the year. As others have said, small planes and ice do not mix, PERIOD. Fly VFR or don’t go if it’s below 34 degrees in clouds at altitude.

Absolutes are never absolute.

Way, way, way more to it that just don't fly in clouds below 34ºF. How thick are those clouds, how dense are the clouds, what's the temperature, etc...

I've blasted up and down through clouds less than 1500' thick under IFR in Michigan when it's been below 34 without issue. Sometimes there's been a small trace but most times theres been nothing. Clouds with some vertical development however...
 
Anyone experienced icing? How much time did you have to escape?

Also someone mentioned flying into an icing airmet is ok but not into a pirep of icing. Is that the only thing that is classified as FIKI for legal purposes?
AIM 7-1-20 table 7-1-10 defines Known Icing Conditions as "Atmospheric conditions in which the formation of ice is observed or detected in flight." I'm not even 100% sure that a PIREP counts. But the Bell letter (which promised in 2009 to revise this definition according to the interpretation in the letter) gives some more detail along with some solid common sense. TLDR: You should study all the information available to you and have an icing exit strategy, otherwise if you survive a serious icing encounter they might punish you.

 
PIREPs definitely counts. In 2005, a student and a flight instructor ended up with a hard landing at Paine Field (KPAE) in Everett, Washington, after accreting airframe ice in a Cessna 172 as I briefly discuss in this article I wrote for FLYING magazine. This landed the instructor a 90-day suspension. The instructor requested an evidentiary hearing and later appealed the FAA ruling to the NTSB. In that ruling the FAA cited several pilot reports that were mentioned on frequency of icing in the area that the instructor should have heard and taken action to avoid getting into ice. So, according to the FAA, pilot reports matter...even those heard on frequency.
The passive voice in the AIM leaves it ambiguous ("observed" by whom?) so it's good to know that the FAA has taken a position on the matter. Is there any clear guidance on how near a PIREP counts as known icing conditions?
 
How does a variable pitch propeller help with icing ? What actions would you take?

Anyone experienced icing? How much time did you have to escape?

Also someone mentioned flying into an icing airmet is ok but not into a pirep of icing. Is that the only thing that is classified as FIKI for legal purposes?
A variable pitch prob can be cycled to flex the blades and maybe pop the ice off.

You have to know how to read the clouds by color and texture and development and experience. And you’ll still be wrong at times.

Time could be minutes to tens of minutes. Usually you climb to get out it.

But with a 172 and no winter experience none of this is relevant - you’ll need to stay out of the clouds.
 
Anyone experienced icing? How much time did you have to escape?
As for many things...it depends. For trace icing, no big deal, just monitor and have a plan to get to better conditions. For lake effect clouds, ice can build in a hurry, like 5-10 minutes to getting a 1/4 inch load on the leading edges and anything sticking out of the airplane, like thermometers and antennas. That's a get outta Dodge NOW.

You HAVE to have bulletproof ice-free outs, and be prepared to not make your destination if flying a light single in winter. They just aren't all weather machines. All the bad weather is in the altitude range available to light planes.

I commuted weekends between DC and Central NY on a couple of stints when I was working in the DC area. The reliability of those commutes was very iffy between November-April. I drove a lot between December-March.
 
I commuted weekends between DC and Central NY on a couple of stints when I was working in the DC area. The reliability of those commutes was very iffy between November-April. I drove a lot between December-March.
Was your mount a Grumman series when you were doing that commute? That's a less forgiving airfoil, optimized more for speed if I recall. Like a Cirus - their deice system is great, but you really need it once the airfoil gets contaminated.

For the OP, how would you feel in your 172 if your leading edges all around looked like the attached. This was on a no AIRMET Z, no PIREP day FWIW. Icing.jpg
 
Was your mount a Grumman series when you were doing that commute? That's a less forgiving airfoil, optimized more for speed if I recall. Like a Cirus - their deice system is great, but you really need it once the airfoil gets contaminated.
Yes, I was flying my AA-5. The wing is pretty fat, and nothing special, but the tailplane is quite thin, and is relatively small. If the wing ices up the tailplane is ugly. It's not an airplane you want to carry a load of ice in.
 
Anyone experienced icing? How much time did you have to escape?

Also someone mentioned flying into an icing airmet is ok but not into a pirep of icing. Is that the only thing that is classified as FIKI for legal purposes?

I have experienced light rime icing a few times. I had plenty of time to consider things and change altitude. In the last two times, I was just in a layer, so requesting lower got me out of the clouds in into water air.

A LOT of discussions online about what is known icing. Some people feel that the only known icing is when you pick up ice. Even a 5 minutue old PIREP may be out of date, EITHER way (more or less ice).
 
Most of my flying has been in VFR conditions, some actual IFR as a student, but all in warmer temperatures. I'd like to go visit family, landing at an airport SW NY (KJHW). Home is eastern NC. Yesterday I did some planning for a potential flight, route of flight if IFR would require 6000 feet, 8000 gives me better height over some mountains. Pireps yesterday reported some light icing. I'd like to not experience icing, and want to bounce off ideas, receive input and thus better clarity on how to stay safe. IFR equipped C172

My thoughts:
1. No night takeoff or landings due to inability to sufficiently avoid clouds and thus moisture.
2. Avoiding visible moisture (clouds) at cooler cruise altitudes will minimize icing.
3. If I can adequately determine cloud layers, I'm thinking to be willing to penetrate through broken layers for VFR on top (and beneath) conditions, especially at lower levels.
4. For a four hour trip, the middle two hours require more altitude.
5. Basically, I want to have mostly VFR conditions.
6. Icing is unlikely to form "out of thin air", if VFR. Clear air = minimal moisture concerns, even if sub freezing temperatures exist.
7. Middle of the day flying better as temperature dew point spread will be more favorable.

Feedback? Thoughts? Thanks.
You have few options over terrain in a pig airplane like a 172. You probably one more window of warm temps coming next week and after that -0°C will be the norm at 7000 feet along your route. I d use it.
 
Yes, the Skew-T log (p) diagram is invaluable. It does not give you the "big weather picture" but can quickly fill in the gaps of important guidance that you won't easily find in those big picture forecasts. For example, I am making a trip from KEWB (New Bedford, Mass) south over JFK to KORF (Norfolk, Va) in a few hours in an aircraft with a certified IPS. The question is, should I stay down low or would it be possible to climb on top into clear air? Here's the Skew-T for the route over KEWB (New Bedford, Mass) which seals the deal for me to stay low with the potential for moderate ice from 7,000 to about 11,000 feet (or a bit higher).

View attachment 121297
Why is it that every one that promote Skew-T thinks thinks they have a trained eye - like the folks at NWS don’t. Skew T is a weather product and just like any other weather product can be wrong.
 
Last edited:
Absolutes are never absolute.

Way, way, way more to it that just don't fly in clouds below 34ºF. How thick are those clouds, how dense are the clouds, what's the temperature, etc...

I've blasted up and down through clouds less than 1500' thick under IFR in Michigan when it's been below 34 without issue. Sometimes there's been a small trace but most times theres been nothing. Clouds with some vertical development however...
Sure, as do I...but for someone that has such limited knowledge that they are asking the interwebs?...Flying a 172??? I think my answer is still valid.
 
Yes, I was flying my AA-5. The wing is pretty fat, and nothing special, but the tailplane is quite thin, and is relatively small. If the wing ices up the tailplane is ugly. It's not an airplane you want to carry a load of ice in.
Nope, not for ice. it's in the 64-415 family (i.e. has some secret sauce LE mods) I believe, which is efficient but won't like ice very much at all.
 
Scary instrument landing in College Station TX last year. It was 35 degrees at 10,000 MSL, overcast 1000, tops 6500, no icing Airmets or PIREPs. I got down to about 3000 on approach when I started noticing the buildup on the wings. Probably should have broken off the approach and diverted, but didn't expect the temperature inversion (which wasn't in ANY forecast). Lucky outcome.
IMG_8070.JPGIMG_8071.JPG
 
Because the Skew-T diagram is incredibly useful. Even though forecasts are always imperfect, they are still useful. If you are in boat that is filling with water and have a bucket with a few holes in it, are you going to use that bucket or throw the bucket overboard because it is imperfect? No, it will still be the best tool you have to remove the water quickly. Similarly, the Skew-T can be extremely useful in many scenarios. But as I have said many times, it's not for everyone...but it can be very useful to those that attempt to unlock its value. To those that don't want to spend the time to learn how to use it, then that's their choice.
Unlock it, trained eye, spend time to learn it ect.

  • What are some of the disadvantages of the Skew-T Log-P diagrams:
  • Available generally twice a day (00Z and 12Z), character of weather can change dramatically between soundings.
  • Sounding does not give a true vertical dimension since wind blows balloon downstream
  • Sounding does not give true instantaneous measurements since it takes several minutes to travel from the surface to the upper troposphere
At least that is what the people providing the data say.
 
Last edited:
A couple people have said to just fly VFR. Let me point out that you can be VFR and still be in fog or haze sufficient to ice. Ask me how I know...

1697058858567.jpeg

A more pedantically accurate statement would probably be, "be in clear air at all times".
 
Unlock it, trained eye, spend time to learn it ect.

  • What are some of the disadvantages of the Skew-T Log-P diagrams:
  • Available generally twice a day (00Z and 12Z), character of weather can change dramatically between soundings.
  • Sounding does not give a true vertical dimension since wind blows balloon downstream
  • Sounding does not give true instantaneous measurements since it takes several minutes to travel from the surface to the upper troposphere
At least that is what the people providing the data say.
As @scottd said, it is one more tool in the tool box. All of our tools for Icing have potential for flaws. Do we only fly in CAVU? Of course not...but not to use all the tool available and disparage one because of flaws common to all is a bit odd.
 
As @scottd said, it is one more tool in the tool box. All of our tools for Icing have potential for flaws. Do we only fly in CAVU? Of course not...but not to use all the tool available and disparage one because of flaws common to all is a bit odd.
I understand tools, but I read far too many Skew-T users who attempt to use the Skew-T to minimize or eliminate by rationalization adverse weather in other products.
 
We did not fly north, laughed at the wx the whole time.
Thanks for discussion everyone.
 
My first “real” icing situation happened last May. I was somewhere over central Ohio at 11k feet just above a 3k foot thick layer. ATC started my decent and sent me to 9k. As soon as I leveled off at 9k I took this picture and informed ATC I was picking up ice and needed to get lower. Immediately I was sent to 5k and broke out of the clouds around 7K. I didn’t get a good picture after I broke out, but I had about double the ice you see in this picture. The plane (C182) felt normal. I dint notice any real difference in handling or air speed. Other then hearing the ice coming off (it was coming off in chunks!) the plane felt normal. It definitely got my attention how quickly this can happen! I was in the clouds for no more then a min when I took this picture. ice.jpg
 
182s will carry a fair amount of ice, especially going downhill which you were. However, were you to need to land with twice as much ice as shown in the picture, you would want to fly a flat, no flap approach, and at a higher than normal airspeed and touchdown speed.

Some 182s are TKS eligible and it’s a great addition if flying in winter.
 
This is a great topic with some really good experiences being shared!

I have flown pretty much everywhere in the United States along with much of the Caribbean and Canada. Generally speaking, I have encountered actual icing in altitudes around the high teens and low twenties.
the vast majority of the time it is light rime that I pick up in climb or decent. The temps tend to be between -15 and -25 degrees celsius.

One of the worst instances of icing and turbulence that I have personally experienced was during a short flight that didn’t get me over 12,000. It was Florida and we had a line of storms we had to get through, which required us to penetrated significant buildup. As soon as we entered the clouds, we immediately experienced moderate to severe turbulence and ice build up. I knew that a run to the left would have better air, so I took it immediately and notified ATC. As quickly as it started, it stopped.

The definition of icing conditions is that the temperature is under 10 degrees celsius and there is visible moisture. That can include haze, fog, wet runways, etc. The training is that if you are going into visible moisture with either Total Air Temperature (TAT) or Static Air Temperature (SAT) below 10 degrees celsius, all of your icing equipment goes on.

As others have said, if you start to pick up ice, your actions will depend upon the aircraft equipment and the amount and type of ice that you are picking up. If you pick up ice, the equipment stays on until all ice is removed from the unprotected surfaces of the aircraft. The reason is that you cannot see what is going on with the tail of the airplane and have to assume that it has ice accretion, as well.

I don’t think that I would fly a 172 in IMC for two hours when icing conditions exist but I would have no problem going through the occasional clouds or going through clouds to get on top or beneath them.

Just like every other part of flying, it is prudent to start slow and pick up experience in very controllable environments, hopefully with someone that has been there before and can help guide you. Mother Nature can be pretty brutal and extreme caution is recommended when dealing with her!

Abram Finkelstein
N685AS
 
Back
Top