climbing through ice

c172captain

Well-Known Member
there was a freezing level last night at 5,000ft. My planned route of flight brought me up to about 12,000ft. There was a broken layer from 5,000ft-FL250. At 12,000ft the temp was about -9, I can't remember honestly.

I decided not to take the flight because the plane has no de-ice.

My buddy, however, said that we would've been fine. Climbing through 5,000ft, we would've picked up some ice, of course, but by the time we got to 12,000ft, everything would've already been frozen. At 12,000ft, we would not pick up any more ice and the remaining ice that we did have would simply falll off, according to him.

What do you think?
 
Excellent decision. A rule of thumb in areas which the surface temperature drops below 50*F during the winter should be that it is more likely to cancel the flight than complete the flight if your aircraft isn't certified for flight in known icing conditions.
 
As others have said, you might have been okay and you might have been able to stay out of the clouds and the ice might have fallen off, but you never really know.

So a good call, yes, but also a simple one. As a CFI I'm sure you're familiar with 91.527.
 
If it had been an operational necessity, there are tools at your disposal to determine the severity of icing you could expect, but for a pleasure/instructional/etc flight you absolutely did the right thing in staying on deck IMHO. Basing an entire flight on the supposition that any ice encountered during your climbout would break away is just poor planning. If it HAD been a necessity, I would have considered pressing IF I could game out a solid "out", like quick re-routing to an alternate field or airway outside/below the freezing level, and of course having sufficient altitude between the freezing level and the MEA (or maybe OROCA) to give you a comfortable buffer to get below the stuff and let it burn off if you ice up badly.
 
Looking at the scenario, I wouldn't touch it unless I knew two things for sure:

One, I could get one top. (you said tops were 25K)

Two, I have a solid out in case it gets ugly. That means good weather below and several suitable airports to get into if need be.

Ice does sublimate off but I've only seen that in clear conditions and it doesn't always happen. Don't ask me why. Going up in freezing rain knowing it's warmer higher up, thinking that will save you, is really not a smart idea. It might be something to file away as knowledge to use during a Plan E, but it's certainly not a good plan A while sitting on the ground.
 
I don't know a whole lot about flying in icing conditions yet - I don't understand how ice will fall off after it's been frozen on - if the temperature at the altitude you'll be cruising at is still below freezing.

I do know that ice should no longer accumulate - if it is already frozen up there when it hits the airplane.

Is the ice falling off after you get through it to colder temps just one of those may or may not happen situations?
 
Well, under Part 91 IFR if it's "known" moderate or greater icing you can't go. That said, sometimes the only way to go is to punch through. I personally won't take anything without TKS or boots up into anything more than light, and I am extremely conservative about flight into any sorts of icing conditions. I will not go unless there're PIREPS less than an hour old confirming that the layer's less than 1000' think with no more than light icing. Sure, I could fly in worse and still be legal. I'm not going to roll the dice, though. In the scenario posed, I'd either be taking an airplane approved for known icing or staying on the ground.
 
You guys ever had an encounter with severe icing? You know, typical day, icing is forecast and then next thing you know, WHAM! 30 seconds after getting the ice your Beech 99 is stalling at 150 knots.

Jayare knots about that, should be dead right now.

Take ice seriously.
 
Well, under Part 91 IFR if it's "known" moderate or greater icing you can't go. That said, sometimes the only way to go is to punch through. I personally won't take anything without TKS or boots up into anything more than light, and I am extremely conservative about flight into any sorts of icing conditions. I will not go unless there're PIREPS less than an hour old confirming that the layer's less than 1000' think with no more than light icing. Sure, I could fly in worse and still be legal. I'm not going to roll the dice, though. In the scenario posed, I'd either be taking an airplane approved for known icing or staying on the ground.

That's a pretty cavalier attitude.

De-Icing and Anti-Icing equipment allows you to transit icing conditions. Nothing more, nothing less. Sometimes it takes us longer to transit the condition than we want.

Flying a light airplane with no deice in any type of known icing, even if it's less than 1000' thick, is putting yourself in odds that are way out of your favor. You really don't know what the accreation level will be. Sometimes I'll look up, see the sky, see the temp and think "Man we're going to have alot of ice." and get none. Other days, the more dangerous ones, you see a real thin layer, think nothing of it, then as soon as you touch the cloud, there is a bunch of ice clining to the airframe, as I was the condensation nuclei.

Ice is only broadly predictable in it's behaviour. About the only thing you do know is that icing conditions exist. The rate of accumulation or the type, you don't know. That PIREP you based your decision off of was a snapshot of what the atmosphere was. Sure it's prolly a stable air day in the upper midwest, but you still don't know what is affecting conditions.

All it takes is you disturbing a super-cooled airmass, providing it the nuclei to begin the chainreaction, and you will be a statistic.

I saw the end result of someone taking that attitude years ago. The pilot was flying a PA-28 something or other. The remants were in a hangar. I could have fit every piece of that airplane through a standard door.

Just some food for thought.
 
You ever hit ice that sounds like ping pong balls bouncing off the fuselage, see the windshield glaze over and then look at the OAT and realize it's -10 and say "oh crap what have I gotten myself into"? Oh yeah, none of it was forecast.

The good thing about clear ice is that it breaks off, if you have boots. Eventually you get comfortible with it (not clear, but some ice) , only if have the a/s to deal with it. Once you run outta a/s, kick into plan B(i.e. descend). Always have a plan B. Ice is no joke, it's scary how fast you can get it in the mountains!
 
You guys ever had an encounter with severe icing? You know, typical day, icing is forecast and then next thing you know, WHAM! 30 seconds after getting the ice your Beech 99 is stalling at 150 knots.

Jayare knots about that, should be dead right now.

Take ice seriously.

Yes, in a caravan. I had more than 5 inches of mixed on and the stalling speed was less than 110 because that was all I could hold in a descent. That was about an inch a minute of of mixed ice. It would take more than 30 seconds to make a 99 stall at 150 kias and a ton more ice than I have gotten on the caravan. I have had Navajo's with 3+ inches several times and they flew pretty well. I obviously don't know what the lower limit was but it wasn't any were close to that high. Take ice seriously is very true especially in airplanes that don't have means of getting it off. I feel if you do have ice protection it's good to know what your plane can do pick it up and see how quickly your speed burns off, what your climb rates are etc. That way you are better prepared to deal with it instead of freaking out like its the boogie man.
 
As others have said, you might have been okay and you might have been able to stay out of the clouds and the ice might have fallen off, but you never really know.

So a good call, yes, but also a simple one. As a CFI I'm sure you're familiar with 91.527.
The 91.500s apply to Large and Turbine-Powered Multiengine Airplanes and Fractional Ownership Program Aircraft.

-mini
 
Yes, in a caravan. I had more than 5 inches of mixed on and the stalling speed was less than 110 because that was all I could hold in a descent. That was about an inch a minute of of mixed ice. It would take more than 30 seconds to make a 99 stall at 150 kias and a ton more ice than I have gotten on the caravan. I have had Navajo's with 3+ inches several times and they flew pretty well. I obviously don't know what the lower limit was but it wasn't any were close to that high. Take ice seriously is very true especially in airplanes that don't have means of getting it off. I feel if you do have ice protection it's good to know what your plane can do pick it up and see how quickly your speed burns off, what your climb rates are etc. That way you are better prepared to deal with it instead of freaking out like its the boogie man.

MMMkay. Yah. No. 3+ on a 'HO? yeah. 5+ on a 'van? You need to work on your reality skills. Just for you 'van drivers out there you can fly with 1/2" on the wing. BUT! either figure out how to get it off, or you are going somewhere else. PERIOD. Even 135, you WILL catch crap from your CP, but if you did nothing wrong, you have nothing to worry about. (That and you're still there to smile!)

I fly the caravan. If you have 5 inches of ice, you're already a smoking hole in the ground. Nice try.
 
MMMkay. Yah. No. 3+ on a 'HO? yeah. 5+ on a 'van? You need to work on your reality skills. Just for you 'van drivers out there you can fly with 1/2" on the wing. BUT! either figure out how to get it off, or you are going somewhere else. PERIOD. Even 135, you WILL catch crap from your CP, but if you did nothing wrong, you have nothing to worry about. (That and you're still there to smile!)

I fly the caravan. If you have 5 inches of ice, you're already a smoking hole in the ground. Nice try.

You obviously don't fly it in the midwest/great lakes.

I have 1500 plus hours in the van(2000+ in pa 31) and I had a VFR 135 pilot riding along that night who has pictures some where. We were at max continuous torque 1653 ft/lbs(600 hp) and in a 500 ft/min descent at 110 kts. I had to shoot an emergency approach to some airport in northern IL that I never saw the surface because it was 200 and 1/2, however we hit the freezing level about 6-400 agl and got enough off to remain airborne.

If you've never been to the edge then you are the one who doesnt know wtf you are talking about. When you get it that bad you point the nose over and do what you can, but you keep flying the plane.
 
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