Ice over 15,000 ft in the winter?

[Dklossner]

Question.  If the outside air temp is below -20c to -30c and you fly into a cloud at or above 15,000 ft can you pickup ice?

I don't think temp inversion is an issue.

 

I don't think you can, based on what I have read, but I would like to pose this question to others. 

 

[jlunseth]

You can pick up ice anytime you are in visible moisture and the temp. is near or below freezing.  However, generally at the temps you are talking about, ice is not likely.  The moisture has turned to ice crystals.  Flying through a cloud of ice crystals is a unique experience, quite stunning.

Water needs a nucleus to crystallize into ice, so it is possible for water to be that cold and yet not freeze (until it finds your airplane).  That is the theory.  In practice, I have not seen icing at temps that cold and we have flown through a fair amount of high clouds in that temp range. 

Generally, there is a pretty good way to tell if a cloud contains water or ice crystals.  Clouds that have edges have water.  The edges may be very irregular, and moving or billowing, but edges they are.  If the cloud is diffuse, without distinct edges, the water has begun to freeze and it is ice crystals.

[KSMooniac]

I've picked up ice at 15k in the summer!  (or near Summer... May over Utah)  That led to a 1.5 day unexpected layover in Moab for me... it went from Canada to nearly Mexico while I was trying to get to CA.  It was -20C IIRC.

[RJBrown]

Point of warning about 231s. Induction ice CAN form and cause a loss of power under those conditions. Happened to me at 22,000' just south of Co Springs. Even with alt air there is quite a loss of power. Basically was on the ILS into Centennial all the way in. Got power back at about 10,000'. Read a story about a delivery pilot over the North Atlantic being forced down to 2 or 300 feet before he got power back. He was stuck right on the deck until the clouds cleared.

http://www.mooneyevents.com/engine2.html

[John Pleisse]

Quote: RJBrown

Point of warning about 231s. Induction ice CAN form and cause a loss of power under those conditions. Happened to me at 22,000' just south of Co Springs. Even with alt air there is quite a loss of power. Basically was on the ILS into Centennial all the way in. Got power back at about 10,000'. Read a story about a delivery pilot over the North Atlantic being forced down to 2 or 300 feet before he got power back. He was stuck right on the deck until the clouds cleared.

http://www.mooneyevents.com/engine2.html

[jetdriven]

Icing conditions are defined in our GOM as any temp between +5 and -40 c anytime visible moisture is present and visibility is less than 1 mile.   I have had icing all through that range.  

[jlunseth]

Quote: RJBrown

Point of warning about 231s. Induction ice CAN form and cause a loss of power under those conditions. Happened to me at 22,000' just south of Co Springs. Even with alt air there is quite a loss of power. Basically was on the ILS into Centennial all the way in. Got power back at about 10,000'. Read a story about a delivery pilot over the North Atlantic being forced down to 2 or 300 feet before he got power back. He was stuck right on the deck until the clouds cleared.

http://www.mooneyevents.com/engine2.html

[FBCK]

How can you tell if you have the newer alternative air option?

[ChrisH]

Is it really a non-issue to have induction ice form and pop the alt-air? I had it happen at FL210, lost about 6" of manifold when it opened. I was nervous enough that I put down to figure out exactly what was happening. But, if it were to happen again, I was thinking I'd still (if possible) decend low enough to thaw the ice rather than continue on alt-air.

I'm not sure it's an issue, is it ok to continue (assuming no visible ice formation on airframe)?

 

[BorealOne]

Quote: N4352H

[Dklossner]

This Forum is a very useful tool.  Thanks for the comments.  It help me deal with a situation that I experienced yesterday.  I have a Bravo.  Flying from Winnipeg to Cleveland.  Left Winnipeg around 2pm local time, filed IFR direct at 21,000.  Picked up a nice tail wind so flight details are as follows; ground speed average 220knts – peak 250knts, 28 inches manifold pressure, 25 degrees leak of peak burning 15 GPH, TIT 1650, RPM 2450, OAT temps ranges from -20c to -35c.  There were two weather fronts, one west of Lake Michigan and one east.  The cloud tops on both fronts were above 21,000 – so I was flying into the clouds when I was transverse the fronts.  The first front cloud conditions were was diffuse, without distinct edges – very light in color and bright, but visibility was poor.  Absolutely no moisture, I did see the ice crystals.  The second front was darker and I figured it was due to the time of day – around 6 pm EST local time – dusk.  The clouds were still diffused, but ice crystals were much more prevalent – outside air temp climbed from -35c to -20c.  Turned on prop heat and pitot tube heat.  The front thickness at my crossing point was about 30 miles.  No ice pickups, but the ALT AIR light come on - no loss of performance - MP stayed at 28 in.  Additionally, communication was lost due to static.  Once through the front, ALT light went out and communication was restored.  In the future I will go around darker diffused clouds if the temp is warmer that -20c, when at high altitudes.    

[jlunseth]

I had to chuckle at that post Dave.  Sounds like my life.  Yes, I don't like dark clouds even in the Flight Levels where they are likely frozen ice crystals.  Relatively small amounts that you can see through are fine.  One's you can't see through can be not so fine, even if just crystals.  I had one long flight from OK to MSP once at FL200, circumventing a very large cell.  The cell was throwing off a haze in the flight levels that extended probably close to a hundred miles from the cell itself.  All frozen, and the trip was uneventful, but I was waiting for something to develop every mile.  Fortunately, was the kind of stuff where there would have been a plan B to get out of it at any time, just not in the direction of home. 

Are your radios Garmins by any chance?  I have read comments on some of the sites about Garmin radios.  I had a 430AW installed, 16W transmitter meant to punch through weather at altitude, and it is not as good as my 30+ year old KY197.  After trying a number of things, including switching the radios between antennas, avionics shop bench tested both radios two days ago and indeed, the Garmin is under spec.  It also varies in output, so good one time and not good the next.  Still under warranty, so we have sent it to Garmin to get it straightened out.  The GPS's are so good, people tend not to notice radio quality, which I guess is not always perfect.  I would get the radios checked.

One trick is to disable squelch.  On the Garmin 430 or 530, this means hitting the power button in the upper left, click it in once.  On a King it means pulling out the little power button.  You will hear a great deal of static that the squelch was suppressing, but you will also hear any transmission if the radio is getting it at all.  The other trick is to use your NRST function.  Once there scroll through the pages to the ARTCC page, and you should find one or more ATC frequencies.  If there is one that is not the one you are on, try them.  I have had a great deal of success with that, usually can reach someone and get back in contact.

There is also an internal sensitivity setting that your avionics shop can access.  We found this was set too high in the Garmin from the factory.  Need to experiment with it a little, because if you turn the sensitivity up too much you will be receiving constant static from some ATC frequencies, and that is a pain in the butt. 

If you are anywhere near Mpls., Modern Avionics is my shop and they are just bulldogs at tracking down these issues and getting thing the way they should be. 

More than one way to skin a cat.