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How do you deal with ice?


SpamPilot

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2 hours ago, Guitarmaster said:

I use Skew-t Log Pro for the iPad.

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+1 for Skew-t Log Pro for the iPad..  Great app, sound investment.  Confirms cloud tops and predictions for icing.  This app and the Foreflight US icing predictive facility are what is keeping me here in Gaithersburg until at least tomorrow.

The ipad app is dead stupid.  Look for separation of the temp (red line) and the dew point (blue line).  Good separation = no cloud at that altitude.  Unless there is potential for clear air icing (which I have not yet figured out how to determine), when the lines are separated (even in the +5 to -20 deg range) there should be no cloud and no icing.  For me, icing potential is defined as the two lines meeting in the blueish band that starts at 0 and goes to minus 20 (or so).

No surprise that Buffalo may have been experiencing icing at 1500' to 2000' (as shown on the chart above).

There is a real comprehensive course on how Skew-t Log charts are made and how to interpret them on https://pilotworkshop.com.  I am 80% of the way through it now.

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5 hours ago, Andy95W said:

Funny thing is when I got my IR in 1991, nobody talked about the Skew-T even though it's been around since the 1940's.  

Actually thermodynamic diagrams (the Skew-T is just one instance) have been around for a lot longer.  My favorite site and the one I teach in my Mastering The Skew-T Diagram premium workshop is http://rucsoundings.noaa.gov.  If you get your glider rating, Skew-T diagrams are a necessity.  I started introducing them to pilots flying powered aircraft back in the late 90s.  Glad to see them being used more and more these days.

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Actually thermodynamic diagrams (the Skew-T is just one instance) have been around for a lot longer.  My favorite site and the one I teach in my Mastering The Skew-T Diagram premium workshop is http://rucsoundings.noaa.gov.  If you get your glider rating, Skew-T diagrams are a necessity.  I started introducing them to pilots flying powered aircraft back in the late 90s.  Glad to see them being used more and more these days.

And what Scott doesn't mention is he has integrated the highly interactive rucsoundings site into his weatherspork app along with everything else a pilot would want. I have the IOS skew-t app as well but this is a significant step up in functionality.


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Today I picked up moderate clear ice from 8,000 to 6,000 over Morgantown WVA.  

I dealt with it using inlet and prop heat, stall warning heat, high pitot heat, inertial separation ice door engagement, windshield heat and boot cycling.  

Washington Center was dealing with a concerned 182 pilot in the area also picking up moderate ice.  

He dealt with it by getting below the clouds and below the freezing level by descending to 4,000.   

It all worked out.  

 

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i fly a fiki model R (no turbo). I often put a five gallon jerry can of refill tks fluid in the baggage compartment as that encourages me to be quicker to turn on the TKS system.  I have LED landing lights which allow me to monitor the airframe ice as the old incandescent lamps melted the ice and the plexi lamp covers are the only visible part of the plane where I can see ice buildup.  I think my biggest concern is too avoid Super Cooled Liquid as this can bring down most all airplanes due to the volume and speed of the ice accumulation so if SLD is forcast on the ice forecast charts I will not fly in that area period.  I always have a plan B for Ice.  This means the route must have viable airports I can land at at should the TKS system fail.  I've had a couple issues, one time a fitting on the tks system blew off so it just pumped the fluid out into the belly pan, another time the prop slinger nozzle broke off (this is a known issue) and again the system could not build pressure and of course it can be easy to use the three hours of fluid and then you are done.  I like to flight plan for as high as I can get prior to the area of icing.  This allows a couple of options, in some cases I am in broken tops and can visually deviate around build ups, In all cases the plane will come down to a lower altitude, so this altitude means my oxygen system is an integral part of flight prep as well as a co2 monitor and warm clothing as my mooney ovation cabin heater can't really keep the cabin warm when the outside temperatures get below minus twenty five.  the coldest ive flown was minus forty and there was ice inside the plane! The great news is that in that kind of temperature my non turbo machine has made it to twenty thousand feet, (but just two persons, STC 310hp engine and minus forty outside and slow climb)  Our descent was through light ice but the tks held it off and due to the high altitude for the flight we ended up using less than a gallon of tks fluid on a four hour trip.  I'm much more careful about flying into ice at night after arriving at an airport in wyoming only to find the runway had more snow on it than I care to land on ever again.  while a larger airport would have been a good alternative, wyoming, nevada and much of canada don't offer that option.  The TKS system MUST be primed prior to ice as it takes twelve minutes to prime at standard flow rates.  I will not take off if the icing is at surface level, so freezing rain etc at the surface and this is due to the ability of ice to accrue way too fast for ice mitigation equipment to shed ice.  I'm told by far more experienced pilots who fly a wide variety of known ice equipment that they use the aircrafts ability to climb as the actual ice mitigation plan and fiki is to allow a normal descent but NOT cruise or hold in moderate or heavy ice conditions. and if your thinking of taking off with ice at the surface, that is only because you have not asked the FBO how much ramp deicing actually costs!   Another way I plan is to stay out of heavy or extreme ice.  So light ice on my route as long as viable alternates along the route etc and if I've already got altitude and no other issues, i'll continue a flight with reports of moderate ice, but I'm working on how to get out of it.  Two weeks ago I was crossing nevada just below a cloud layer when ATC explained that due to radar coverage limitations and minimum enroute altitudes, he was asking if I could go higher so he could launch a medivac out of ely nv.  I turned on my TKS and climbed to 17k which it turned out was as high as I could get due to it only being about minus five celsius and I listened to the light twin pilot plead with the controller to get him out of the ice he had climbed into, below me!  I assume he was not FIKI or we (he and I) had flown into an area where the ice was much worse lower in the clouds.  As I had only about one hour of TKS fluid left (I had departed wisconson and been in and out of ice the whole flight) I soon hit bingo TKS fluid level which for me is forty five minutes remaining, so I had to deviate to hawthorn nv and land.  I had about an inch of ice on the landing light covers so it was a moderate ice day for sure.  Having seen how fast ice can build on an airframe i think that ice must be treated as one of the most dangerous aspects of flying that ranks equal to thunderstorms.  there is a great deal of really good information on icing available,  most of the material is based on aircraft with climb power double or triple that of our small planes and those guys died, so i put a lot of thought into when to fly, where I'll fly, and what altitude.  I fly coast to coast a couple times per year and it isn't uncommon for me to be forced from the canadian border all the way down to texas to get around weather which exceeds my single piston capabilities.  hope this helps

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On 10/29/2018 at 5:37 PM, Jerry 5TJ said:

Today I picked up moderate clear ice from 8,000 to 6,000 over Morgantown WVA.  

I dealt with it using inlet and prop heat, stall warning heat, high pitot heat, inertial separation ice door engagement, windshield heat and boot cycling.  

Washington Center was dealing with a concerned 182 pilot in the area also picking up moderate ice.  

He dealt with it by getting below the clouds and below the freezing level by descending to 4,000.   

It all worked out.  

I was in that mess yesterday too.

1075309587_FlighthomefromGaithersburg.thumb.jpeg.100d6a4ae749e138a62f083154f1154f.jpeg

I held off two days because of the forecast ice.  Yesterday was the first day that showed layers (that should be free of ice) and most tops below 9000'.  Worked great until abeam of Elmira airport (about 90 minutes into a 3 hour flight).  Tops came to me and I started picking up ice.  Plan B = ask lower looking for warmer temperatures and continue on route.  If Plan B fails, go to Plan C - ask lower again and direct Elmira (approach to the current runway in use was already loaded)

Plan B worked.  Down at 5000' (I picked a route where the MEA was mostly 3000' or 3500' feet, all below the forecast icing level) I was now in clag, but temps were +1 and melting of the little bit of ice accumulated thus far.

Until Syracuse where you can see the "visible moisture" showing on the Flightaware graphic above.  In talking to Wheeler Sack, asked for 3000', and they held me off until a Piedmont flight out of Watertown (north of Syracuse) had passed beneath and behind me.  I was on my way down to higher temps when he told me that Montreal Centre (the FIC that controls Canadian airspace north of the New York - Ontario border) would not clear below 4000'.  So I stayed at 4000' but the temps were as high as +1 and ice was continuing to dissipate off of the leading edge of the wing.

15 mins later, started collecting more and told Montreal, asking for lower.  The switched me over to Ottawa Approach who indicated they understood the problem and let me down to 3000'.  But now I had to steer way clear of Ottawa International before I could commence the very easy RNAV approach to Rockcliffe (CYRO = my home drome) that had at least 1200' clear below cloud (easy-peasy).  Took a 25 mile detour because of the heavy iron heading into Ottawa (CYOW).  Temps varied from -1 to +1 the whole of that part of the approach to the IAF.  Ottawa approach had volunteered to allow me to conduct an ILS to one of their runways and then proceed VFR to Rockcliffe (about 8 miles apart) because the tower reported they could see over to Rockcliffe. 

Rejected.  I have a 480 and a G5.  Don't need to risk getting messed up in attempting to make it VFR.   Set up for the approach - conduct the approach - if missed, go to the alternate already set up.  Simple.

Then Ottawa Approach suggested an approach to Gatineau (5 miles on the other side of Rockcliffe) because they had higher ceilings than Rockcliffe.  Rejected.  Same reason.  Frankly, if I am unable to make an RNAV approach into 1000' overcast with the equipment I now have on board, I should turn in my license.  At the altitude I was flying, icing was no longer an issue.  Still had some on the wings, but there was no more accumulation.

So they cleared me direct to the IAF, (meaning out of controlled airspace) and reiterated the missed approach procedure and confirmed the procedure to cancel the flight plan in the air or on the ground.

By this time, there was at least one approach controller focussed on me as his primary responsibility.  I could tell by his voice.  Made it to the IAF with no more accumulation of ice and followed the procedure.  Five minutes after stabilizing on the RNAV G/S and Loc, I came out of the clag and saw the runway (about 4 miles out).  Cancelled the IFR at that point and heard the relief in the voice of the controller.  

When I got to the gas pumps to fill up, I looked at the ice on the wings and saw they had between 1/4" and 1/2" protruding forward of the leading edge.  Apparently my Mooney flies OK with that accumulation.

Lessons learned (aren't there always lessons to learn?):

  • Don't do this again.  Iffy is still iffy.  
  • This was not a dangerous flight, but it could very well have been.  Real easy to go south at a lot of points.  One degree adverse change in temperature and I would have collected a hockey sock full of ice.
  • Keep options open.  Had lots on the US side, and discussed them with Elmira, Syracuse and Wheeler Sack approach controllers - very useful.  not so many on the Canadian side and they had a lot more heavy iron to consider than the ones in this part of New York..  
  • The red fluorescent piece of tape on my inboard left wing allowed me to determine accumulation of ice without having to squint.  I put that on 6 years ago.
  • Keep the speed up.  Icing freezes the stall warning tab in place and ice increases the stall speed of the aircraft. Turn on final at the IAF was done at 120 mph.  Drop the gear only after the runway is in sight.
  • OAT on my JPM 700 (put on two years ago) was my primary non-six-pack gauge from north of the PA-NY border.
  • Don't do this again.  Iffy is still iffy.  (Repetition is a good learning tool)

I knew yesterday was possible and I could have stayed one more day in Gaithersburg and flown home today. I also knew the forecasts for today provided a picture of much better flying conditions.  Next to non-existent icing predicted for between 4000' and 9000' the whole route home.

But I guess I needed to learn the lesson:  Iffy is still iffy.  

I will not do this again.  

 

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All of this feedback has been fantastic.  Some comments on tools:

- Nobody has mentioned the ADDS Flight Path tool.  One big benefit of this tool is that you can enter a series of waypoints and it will plot icing severity/likelihood (or other values, such as temperature and humidity) as a function of altitude along your flight path, with a terrain overlay.  It's a great way to get a sense for where the dry air is above you and how far the warm air is below you at any point along your path of travel.

- Skew-T is a plot of basic data captured by a weather balloon that was released at a particular station.  These stations are not especially close together; they are often farther apart than the size of weather features I'd want to avoid (but they are essential measurements nonetheless).

- Both the ADDS tool and the Graphical Forecast for Aviation tool forecast icing and other conditions such as cloud tops at a finer level of spatial granularity than Skew-T, and they do it in a way that I feel is easier to comprehend.  Many Skew-T plots don't translate pressure into altitude, for example, but both ADDS and GFA speak MSL.  ADDS and GFA are terrain-aware.  ADDS and GFA give you more ways to think about plotting paths around, over, or under weather.  The caveat is that these are forecast tools that rely on mathematical models to predict atmospheric conditions across areas between where measurements are made, and how those conditions will evolve over time.  Crudely speaking, you can count on them being wrong.  The Skew-T plot is truth, or rather was truth at the time of the sounding, and is no longer truth by the time you see it, but might be close to truth if things aren't changing rapidly and you are near one of the sounding sites.

Now a couple questions:

- A few have commented on the value of climbing when encountering ice (and a few have commented on the uncertainty embedded in that decision).  OK, so for those of you climbers without FIKI, assuming there is no known icing, no precip, and you have a believable estimate of cloud tops, what's the thickest layer of below-freezing cloud you would attempt to climb up through?  Similarly, what's the thickest layer of below-freezing cloud you would willingly descend through?

- Let's say ATC clears you to a below-freezing altitude.  You're in VMC, so no sweat.  After a period of time, you realize you're heading straight into a wall of cloud that you can't get over, can't get around, and can't get under without descending below the MEA, which is itself below freezing.  The cloudiness might not extend very far, based on METARs further along your route, but it could take several minutes to get through to better conditions.  Do you a) request a 180 and divert, declaring an emergency if they don't accommodate you, or b) enter the cloud to see what it's like, prepared to make a 180 at the first indication of ice?

Edited by SpamPilot
typo
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For those who may experience icing: 

https://www.aircraftspruce.com/catalog/cspages/bfgicex.php

https://www.skygeek.com/goodrich-icex-ii-de-ice-boot-adhesion-inhibitor.html

 

IceX is a thick-ish viscous silicone coating that we use in our flight department on aircraft that have boots. It does not last 50 hours. It lasts one flight, and it makes a little bit of a slimy mess as it migrates back over the wing. (wipes right off, easy cleanup) . However, it works equally well on aircraft without boots. It's job is to prevent ice from sticking in the first place. Clearly, ice will form on the curve of the leading edges no matter what product you put on there. But, IceX will help prevent it from adhering as well, so buildups tend to be smaller and to come off. 

On our Pilatus PC-12, I've seen a fresh coating of IceX allow us to fly without using the boots at all. You can clearly see it buildup to about 1/16 inch thick, and depart. 

Understand, I don't say it's a solution or a fix. Only that a very fresh and thick coat of the stuff "can" help. 

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On 10/30/2018 at 9:57 AM, Ned Gravel said:
  • The red fluorescent piece of tape on my inboard left wing allowed me to determine accumulation of ice without having to squint.  I put that on 6 years ago.

I was in same boat from Manteo to Kitchener, but chickened out and waited 'til Tuesday.  Beautiful flight, but nasty headwinds (as usual).   I've used skew-ts any time I'm heading near icing.  Now that windy.com includes skew-t, it makes it much much faster and easier,  It's good that we can all learn from the experiences of others.  The fluorescent tape idea is a GREAT one.  I'm doing the same next time I'm seeing Gladys.

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2 minutes ago, Cyril Gibb said:

I'd hope that it would provide more contrast than ice on a white wing.

Wouldn’t a dark color be better, I’m thinking the black boots seem to show the ice well based on pictures, no firsthand experience. Most modern paint schemes have dark colors on inboard part of the wing, don’t know if that’s intentional or not.

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Wouldn’t a dark color be better, I’m thinking the black boots seem to show the ice well based on pictures, no firsthand experience. Most modern paint schemes have dark colors on inboard part of the wing, don’t know if that’s intentional or not.
The Ice shows up very well on the black that's painted on the front of my wings.


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On 10/30/2018 at 6:57 AM, Ned Gravel said:
  • This was not a dangerous flight, but it could very well have been.  Real easy to go south at a lot of points.  One degree adverse change in temperature and I would have collected a hockey sock full of ice.

Yikes, glad you made it through!  Hopefully, they'll find the seat cushion someday! :lol:

"Hockey sock full of ice"??  haven't heard that one before :rolleyes:

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