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Icing definition for legality to go.


Will.iam

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So i remember flying with my dad we used to fly through clouds all the time in texas even in winter and never gave icing a thought as FIKI wasn’t an acronym back in those days. Just make sure there wasn’t any pireps of icing or make sure the freezing level was higher than your landing elevation. Fast forward to the lawyer world of word salad we have today and with icing being 0 degrees C and visible moisture and placards stating flying into known icing is prohibited that knocks me out of any IMC at those temps which even in the summer i can find in the south if i climb up to where i need oxygen. How do pilots mitigate this issue when they have non FIKI airplanes? I did find it interesting that at one legacy airlines they do not use their anti-ice when in 10 degrees or colder and  visible moisture that has 1 mile visibility or greater. That would give more flexibility for use ability in our GA non FIKI if that was allowed for us GA’s as it seems as it’s written now in winter time i’ll have to be strictly VFR to abide by the letter of the law. Or am i reading this all wrong and you can fly through a cloud if no icing is forecasted in that area and no pireps have been reported? I guess where I’m getting hung up on this is there are varying levels of moisture and in different states gas liquid or solid in clouds as the majority of clouds do not have ice forming conditions, and if you do get icing changing a couple of thousand feet up or down gets you out of the icing even though you are still in the same cloud layer area. So having a blanket statement of icing is visible moisture (any cloud) at 0 degrees C and below makes that flight not legal.  Seems in the pursuit of safety we have lost the ability to use judgement to the detriment of not being able to go. to be more defined like visibility less than a mile or inadvertent encounter is ok as long as you have an escape route either laterally or vertically would make more sense. 

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My impression of this is something like "if you get into ice, you better not look like a lier or moron while explaining why that ice was a surprise."
Which matches my overall rule for flying and life of "don't do things that will sound stupid in an incident report."


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1 hour ago, tgardnerh said:


My impression of this is something like "if you get into ice, you better not look like a lier or moron while explaining why that ice was a surprise."
Which matches my overall rule for flying and life of "don't do things that will sound stupid in an incident report."


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Like if there’s 3 pireps and an airmet for ice, then maybe it’s not a good day to “check it out”.  However, if it’s just cold and cloudy, yet you have a good “out” plan (maybe vfr and warm below you?) and don’t plan to cruise in it, maybe it’s ok to blast through a layer…

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Like if there’s 3 pireps and an airmet for ice, then maybe it’s not a good day to “check it out”.  However, if it’s just cold and cloudy, yet you have a good “out” plan (maybe vfr and warm below you?) and don’t plan to cruise in it, maybe it’s ok to blast through a layer…

Though blasting through a layer is tricky--once you're in it, you know it's there, so you better have a plan for coming down that doesn't involve the same icing layer (eg destination is clear). Otherwise you're knowingly planning to fly through ice.


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41 minutes ago, tgardnerh said:


Though blasting through a layer is tricky--once you're in it, you know it's there, so you better have a plan for coming down that doesn't involve the same icing layer (eg destination is clear). Otherwise you're knowingly planning to fly through ice.


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Yeah, maybe.  Icing is fickle enough that there’s a good chance of coming down 30 miles away and seeing nothing.  Isn’t that the rule of 3s?  30 miles, 3000’ or something like that?

Anyway, I don’t recommend being stupid about it as our planes aren’t good at all in icing, but coming down through 1000’ of cold clouds at say 6000’agl when there’s warm air below and no recent pireps seems ok.

I flew a (fiki) small turboprop airplane out of Seattle on Tuesday.  It snowed most of the morning and then 36 degrees rain.  Much colder above.  I knew I needed to get above about 18k to get above the ice for sure.  I was pretty sure we would have ice from 1000’ and up.  Imc the whole way.  Zero ice all the way to 21,000’.  Icing is weird.

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The airframe can be a few degrees warmer than the ambient temperature because of ram effects. Garmin (at least on the G3X) corrects RAT (ram air temperature measured at the probe) for true airspeed heating effects and displays a corrected OAT. I've noticed that I can fly at 0 deg C OAT in clouds and never pick up ice. There is an option to display RAT on the G3X data bar.

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2 hours ago, PT20J said:

The airframe can be a few degrees warmer than the ambient temperature because of ram effects. Garmin (at least on the G3X) corrects RAT (ram air temperature measured at the probe) for true airspeed heating effects and displays a corrected OAT. I've noticed that I can fly at 0 deg C OAT in clouds and never pick up ice. There is an option to display RAT on the G3X data bar.

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Just be careful (or cognizant) about the places that are actually colder than the rest of the airplane due to the low pressure airflow around them (obviously pitot tube is heated).  It seems every airplane has its “cold spot” where you’ll first notice ice.  Maybe it’s more noticeable on fast aircraft?  On the F-15, we’d look out the wing at the round “glass” seeker head on the AIM-9 missile (inert, but still a real seeker head for training).  You would always get ice there a couple degrees before it started creeping up the windscreen.  

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1 hour ago, Ragsf15e said:

Just be careful (or cognizant) about the places that are actually colder than the rest of the airplane due to the low pressure airflow around them (obviously pitot tube is heated).  It seems every airplane has its “cold spot” where you’ll first notice ice.  Maybe it’s more noticeable on fast aircraft?  On the F-15, we’d look out the wing at the round “glass” seeker head on the AIM-9 missile (inert, but still a real seeker head for training).  You would always get ice there a couple degrees before it started creeping up the windscreen.  

My understanding is that ice builds up first on sharp leading edges, someone mentioned the wingtip fence and the OAT probe.  At least, that's the case on GA aircraft, there may be different effects at F-15 speeds :) 

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Though blasting through a layer is tricky--once you're in it, you know it's there, so you better have a plan for coming down that doesn't involve the same icing layer (eg destination is clear). Otherwise you're knowingly planning to fly through ice.


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That’s really not the issue. non fiki aircraft encounter icing all the time. nor is giving a pirep for icing an issue. the issue is when you get into it you don’t have a plan B to get out of because your flight planning didn’t provide for icing contingencies and your stuck in it. But if your planning gives you an out no one is going to deviate you. Really you have to practically fly into severe icing with no contingency options to get out to get deviated - as pretty much stated in the Bell legal interpretation.
The end result comes down to experience, and equipment, where a lack of experience demands an order of magnitude more conservatism.


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1 hour ago, jaylw314 said:

My understanding is that ice builds up first on sharp leading edges, someone mentioned the wingtip fence and the OAT probe.  

That’s correct.  Anything with a high radius of curvature allows for efficient ice accretion.  So ice accretions themselves make efficient ice collectors.  

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49 minutes ago, kortopates said:

I probably should have included knowledge with experience. I tend to think most pilots gain the knowledge with the experience but i know Scott will readily point out he sees plenty of exceptions as an educator. :)
 

Yes! Having trained thousands of pilots over the last 25 years, the lack of knowledge is likely the biggest reason pilots make poor preflight and inflight decisions. I am not saying that experience is useless, but often risk is addictive. Pilots often gain the wrong experience and use previous successes as the reason for their next go decision. Just because that 3,000 ft stratocumulus deck that they climbed through over the last 10 times resulted in little or no ice accretion, doesn’t mean it’ll be the same on the 11th try.  Turns out that the air was much cleaner on the 11th go which resulted in SLD in the climb nearly killing a pilot.   He reached out to me to learn why.  He learned a ton and now has knowledge to make a better decision-experience alone did not serve him well.  Knowledge combined with experience (applied knowledge) is extremely valuable. 

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20 hours ago, Will.iam said:

I did find it interesting that at one legacy airlines they do not use their anti-ice when in 10 degrees or colder and  visible moisture that has 1 mile visibility or greater.

Is this the consideration for the use of engine anti-ice for a turbo jet? That is a whole other pickle barrel as you have a huge pressure drop in the inlet which causes rapid state changes in moisture. Once you drop below 1 mile vis, you have huge amounts of moisture condensation before the fan.

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38 minutes ago, Scott Dennstaedt, PhD said:

Yes! Having trained thousands of pilots over the last 25 years, the lack of knowledge is likely the biggest reason pilots make poor preflight and inflight decisions. I am not saying that experience is useless, but often risk is addictive. Pilots often gain the wrong experience and use previous successes as the reason for their next go decision. Just because that 3,000 ft stratocumulus deck that they climbed through over the last 10 times resulted in little or no ice accretion, doesn’t mean it’ll be the same on the 11th try.  Turns out that the air was much cleaner on the 11th go which resulted in SLD in the climb nearly killing a pilot.   He reached out to me to learn why.  He learned a ton and now has knowledge to make a better decision-experience alone did not serve him well.  Knowledge combined with experience (applied knowledge) is extremely valuable. 

Normalization of deviance is a problem that sometimes comes with experience. Getting away with something stupid makes you more likely to try it in the future.

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30 minutes ago, ilovecornfields said:

Normalization of deviance is a problem that sometimes comes with experience. Getting away with something stupid makes you more likely to try it in the future.

The problem is that most of these pilots don’t know it is stupid since they were never taught otherwise.  

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2 hours ago, GeeBee said:

Is this the consideration for the use of engine anti-ice for a turbo jet? That is a whole other pickle barrel as you have a huge pressure drop in the inlet which causes rapid state changes in moisture. Once you drop below 1 mile vis, you have huge amounts of moisture condensation before the fan.

Generally it is non-precipitation visible moisture and 1mile visibility. Any precipitation and 10C or less corrected for Ram effect would necessitate using the engine heat/anti-ice. Fog, mist, haze with greater than 1 mile visibility would not necessitate using engine heat/anti-ice.

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7 hours ago, AIREMATT said:

Generally it is non-precipitation visible moisture and 1mile visibility. Any precipitation and 10C or less corrected for Ram effect would necessitate using the engine heat/anti-ice. Fog, mist, haze with greater than 1 mile visibility would not necessitate using engine heat/anti-ice.

That is correct.

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I watched an old John Wayne movie last week. Island in the Sky. Pretty good portrayal of how it used to be with ice.

We have the problem to deal with quite a bit where I fly. Once ground temps are in the 40’s, actually low 50’s too, even small gains in altitude can put you in ice. It is weird though, very. We get relatively thin (2-3,000 feet thick) stratus layers most of the winter. The problem is not the short climb to get up through it, the problem is what if you have to fly an approach coming back down, the approaches here are all right where that layer is so you can be in the middle of it for too long. The three or four times I have encountered ice have been during freak summer conditions though. 

I agree with those saying you need to have an out. If there is no out, or if “out” is to fly an approach in the layer, it is time to just sit on the ground.

PS I find the skew-T log-P graphs to be very useful in determine where ice might be along a route.

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On 12/1/2022 at 11:57 AM, Ragsf15e said:

Like if there’s 3 pireps and an airmet for ice, then maybe it’s not a good day to “check it out”.  However, if it’s just cold and cloudy, yet you have a good “out” plan (maybe vfr and warm below you?) and don’t plan to cruise in it, maybe it’s ok to blast through a layer…

Well said. Treat ice with the respect it deserves and the legalities will take care of themselves. Most likely you will only encounter Enforcement action if you land with the airplane coated in ice. If that happens you will be more worried about changing your shorts and grateful to be alive than a ramp check.

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