How much ice?

[Bob - S50]

Just curious.

Living in the Pacific NW, as many of you suspect, we have a few cloudy days in the winter.  Trying to go east involves climbing over an MEA of 8400' or going down to the Portland area where the MEA is 7000'.  Since I've been avoiding potential icing like the plague, it limits doing Angel Flights over to the Spokane area.  My philosophy has been, whether moderate icing is predicted or not, if a look at the skew-t doesn't indicate that I can be above the weather by the freezing level, I don't go.  I either want to be able to stay below the weather or climb through it and be on top before I get to the freezing level.

Wondering what others think.

Light icing?

Trace icing?

Time exposure during a climb/descent through the weather?

[FlyDave]

Bob,

I have had up to 1/4" of rime ice on my bravo with no noticeable degradation in airspeed.

But one time, climbing out of Portland I accumulated at least 1/4" of clear ice in approximately 15 seconds - that got my attention. There were no airmets/sigmets for ice and the ADDS icing page ( http://aviationweather.gov/adds/icing ) forecast no ice. In my limited experience I have found what others say to be true: Ice is where you find it!

Here is the M20K evaluation that discusses airframe ice - but that's a turbocharged plane:

http://www.mooneypilots.com/mapalog/M20K231%20Eval%20Files/M20K231_Eval.htm

Dave

[gsengle]

Unless you are FIKI equipped, didn't the FAA rule that all visible moisture below freezing (clouds) should be avoided? Very strict interpretation I know but I seem to recall this a few years back.

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[peevee]

I'm pretty new to the turbo, but my philosophy is similar to yours, below freezing + clouds = not going in. 

 

If I can top it and still have an out below to get out I might go but I haven't yet. 

 

Sure there have been days I wish I had flown but I haven't had one yet that I wish I hadn't! 

[Marauder]

I did a lot of winter flying in western NY. The clouds there can pick up a lot of moisture from the Great Lakes but can be non-uniform. In other words, some clouds just seem to pick up and hold more moisture than others. That basically meant that icing was unpredictable in location. I flew a number of times at same altitudes as other GA pilots and they reported picking up ice and I had nothing or vice versa. It also meant that icing airmets were issued routinely and covered the whole area.

My approach to winter flying when it came to ice was to go below if possible or fly through clouds when I knew the tops were achievable. If the clouds were layered above 3,000 or 4,000 AGL, I typically wouldn't go. Another thing to consider if you needed to shoot an approach. If I knew the destination airport's approach was going to have me in the clouds for a period of time, I would not fly.

I learned the best way to deal with it was not to.

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[xrs135]

It's pretty critical to stay out of icing conditions in any small plane that's not FIKI equipped - especially laminar flow wings. 

Hell, I've been in enough icing conditions flying RJ's around the country that I wouldn't consider taking a small GA plane into, period (even if it was FIKI equipped). 

Like Dave said earlier... Ice is where you find it.  However, there are certainly things you can do to reduce and eliminate your chances of encountering it. The FAA's rules pretty much guarantee that you will remain out of icing conditions. Is it conservative? Yes. But when it comes down to it, if you stay out of all visible moisture when the temperatures are below freezing, you WILL NOT encounter ice. 

Edited January 3, 2016 by xrs135

[glafaille]

The problem with ice is that it is VERY unpredictable.  That is why the term "known icing conditions" is often hard to describe or predict.

I've flown for many hours in visible moisture at temperatures below freezing and never gotten a bit of ice.  Yet several times I've been in the same conditions and picked up plenty (not in a Mooney).  

The best advice for ice I can give is to always avoid it wheather your aircraft is equipped for it or not, AND alway leave yourself an "out".  A properly equipped aircraft will still accumulate airframe ice and still suffer a degradation in performance.  However the deicing/anti-icing gear will USUALLY allow you to withstand the ice long enough to get out of it if immediate action is taken. Never rely on deicing/anti-icing equipment to protect you indefinately and remember that severe icing can bring down just about anything.

[M20F]

22 minutes ago, gsengle said:

 

Unless you are FIKI equipped, didn't the FAA rule that all visible moisture below freezing (clouds) should be avoided? Very strict interpretation I know but I seem to recall this a few years back.

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They did and then subsequently changed it back to being essentially the PIC's determination. 

Ice comes with two problems.  One the ice itself which can be unpredictable.  It can accrete slowly, quickly, show up where it shouldn't, etc.  Ice not only causes issues with lift by disrupting air flow but it is heavy.  It doesn't take a lot of  ice to start adding into a lot of pounds which when coupled with lessening lift is a real bad problem.  The second is you are almost always going to be in IMC when you get ice.  Thus you take the stress of IMC and add a additional complexity. Because none of us actively go out looking for ice our experience with it and what it will do is very limited which makes flying with it or in it difficult to ascertain what will happen.  

In short it is a bad deal and because I fly for fun I give it a very wide passage.  My personal experiences with ice have been few and while calm and collected working the problem, on the ground I certainly felt that repressed fear come out.  Not a pleasant experience.  

[Immelman]

How much ice? No ice.

You owe it to your angel flight pax, who have no idea what they are getting themselves into. You owe it to your airplane, so it flies another day, and to yourself and your family.

"If the weather is bad, go IFR, if its really bad, go VFR". This is a statement I take to heart in light GA airplanes without ice protection. Stay clear of the clouds, and you'll be clear of the ice.

I can't begin to tell you how awful I felt to have my wife sitting next to me, as out of nowhere clear ice splattered onto the airplane like it was being shot out of a fire hose, running back from the leading edges in long icicles. Stupid, very stupid, a true "NEVER AGAIN" moment... and I did have  the brains to only try that with a solid OUT (warm temp below, over the Willamette valley). Over the mountains?? You gotta be kidding me.

Edited January 3, 2016 by Immelman

[gsxrpilot]

Just now, Immelman said:

"If the weather is bad, go IFR, if its really bad, go VFR". 

Truth.

[carusoam]

Keep in mind there are visible clouds that are made up of completely frozen ice crystals...

1) It would be difficult to pick up ice from them.  

2) You will have a chance of some significant static build up while going through them. 

3) You can have the leading edge paint removed by them.

To use this knowledge, it helps to know where the clouds are forming.  Fresh off the Pacific Ocean, and Great Lakes is ripe for super cooled water droplets looking for sheet metal to catalyze crystallization upon.

I have experienced icing twice.  Both times with flight instructors. Ice grows quickly.  The amount of ice on the wings is one thing. The amount of ice on the prop is hard to see.  The ability of ice to stick is amazing. The O had a small icicle extending from the tip of the spinner. Also consider the effect of ice forming evenly on the prop, then shedding unevenly one chunk at a time....

Ice- Avoid it, and get out of it the best you can.

As for no noticeable performance change with 1/4" of ice on the wings...

- expect changes in weight, lift, and thrust, will directly impact speed, stall behavior and recovery.  Flap and speed brake operation may be inhibited....

Thoughts of an engineer/PP, not an instructor...

Best regards,

-a-

[WardHolbrook]

I retired last year after a 35 year career flying corporate jets. I spent 15 of those years flying for a company up in the Pacific NW. Our company was based in Oregon and when it comes to icing, few places will equal what you'll find up in the Pacific NW - with all of the moisture from the ocean and cold air coming down from the north, those Cascades generate as much ice as you'll find anywhere. I've had my share of icing encounters up there and it's nothing that you'd want to mess around with unless you have the proper equipment and the skill and experience to use it properly. One of the problems with icing forecasts is that they're often wrong which means that icing is really where you find it, when you find it. This can lead to guys not taking it seriously after all, how many times can you yell "wolf" before people don't take you seriously? Big mistake. I've also flown in my share of icing in FIKI equipped light aircraft and I have no qualms about doing so; however, the rule about always leaving yourself a way out always applies. Ice is one of those hazards that can and will kill you if it's not respected and dealt with properly. I had a highly experienced friend killed in a FIKI twin Cessna he was flying, it was winter time and he got into some icing over the Cascades. He failed to take action soon enough and it simply overwhelmed him. I think that for a non-FIKI aircraft up in that part of the country, conservative is the only way to go - no amount of ice is acceptable. It's not just the ice that builds up on the wings, it's also the ice that forms on the propeller blades. Ice distorts the airflow and destroys the wing's lift. It does exactly the same thing when it forms on the prop. The resultant loss of thrust only exasperates your problems. (Robert Buck, in his book Weather Flying, discusses flying in ice. It's worth your time to review what he has to say about it.) The bottom line is ice is one of our deadly enemies and must be treated as such which means that there will be times during certain months of the year that a wise and prudent pilot in a non-FIKI airplane will just have to sit it out. Be safe my friend.

Edited January 3, 2016 by WardHolbrook

[N201MKTurbo]

I got a far amount of experience flying in icing conditions back in the eighties when you could fly anywhere until somebody made a pirep of icing. 

One thing I learned was that if you encounter icing, the place you were a minute before has no icing. Go back there. Do a 180, climb or descend, whatever gets you back to where you were before you started picking up the ice. 

When I advised ATC that I was picking up ice and needed to do something, they never said no. If they would have I would have declared an emergency and done it anyway.

[WardHolbrook]

Pop Quiz...

In what year did the DC-3 receive flight in known icing certification?

A. 1937

B. 1939

C. 1943

D. 2008

Edited January 4, 2016 by WardHolbrook

[M20F]

30 minutes ago, WardHolbrook said:

Pop Quiz...

In what year did the DC-3 receive flight in known icing certification?

A. 1937

B. 1939

C. 1943

D. 2008

It's either 2008 or never.

[WardHolbrook]

Believe it or not it was 2008. Basler Aviation in Oshkosh did it. You've got to wonder how the DC-3 survived flying in all types of weather for 75 years without it.  

[aaronk25]

Like others said stay out of it. Certainly don't trudge though it or "stay the course" with the belief it won't last long.

In MN we get a lot of over cast at 2000 with tops at 3000-5000ft. In that case I'll take several factors in mind and it varies upon weather I'm climbing or diving through it. Some of the things I'll take into account if climbing are aircraft rate of climb at given weight and DA, what do skew charts look like (is there another layer above), ground temp as well as predicted temp above the layer, how old is tops Pierep?, does the tower have any additional useful info about tops and ice, can the climb rate prior to entering IMC be decreased in order to let the aircraft accelerate to an increased airspeed so a higher than normal rate of climb can be realized in order to blow though the layer, will ATC allow this as in busy airspace as they most likely will want to keep you right in the crap for sometime, after all this what is that OAT above the layer and if ice is picked up how long at the OAT will it take for it to sublimate and how does the ice effect your climb rate down the road if it doesn't sublimate right away...is there more weather you have to top down the road, with a iced up plane and going back to the destination doesn't look very good as you have to go back though the ice to land, what happens if something goes wrong with the plane how does the ice effect the emergency?

All these are things that most likely make it a no go decision.

I've done my share of diving down though a 1-3000ft layer coming home at a home base airport with a Ils and 10,000ft runway but there is no way I would do it on a approach that was less than vfr min.

Food for thought be safe

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[Loogie]

 

"I have had up to 1/4" of rime ice on my bravo with no noticeable degradation in airspeed."

This is the type of thought process that gets aviators on trouble.  Ice is dangerous on any airplane, specially single engine piston types.  The problem w ice is it is very difficult to evaluate the loss of performance, until you need it.  If that mooney wing is covered with 1/4" of rime ice, there is absolutely a degradation, while you might be able to hold what you have in terms of airspeed, I can guarantee that the critical angle of attack will have changed, in the wrong direction...it will also stall assymetrically and provide some non-tested flight characterstics etc.. 

Lots of good advice in this thread on dealing w ice, glad to see good judgement and conservative thought being pushed in ref to ice.  

Even a/c certified for flight into known icing are susceptible to serious performance degradation, ask a young King Air crew over Baghdad how they felt recovering from a ice induced spin at 7k and bottoming out at 700agl, I asked them, and let me assure you they never stayed in icing anymore than what was required to get the heck out of it. (I was the boss for 11 squadrons in combat).  I have a thousand stories of ice in fighters, bombers and ISR a/c, not all of them have a happy ending.  Needless to say guys, don't fly your Mooney's intentionally into ice, avoid it, and make smart decisions when you find it.

 

 

[N33GG]

Icing can be no big deal, or it can accumulate rapidly and bring you down like a snowball. And forecasts are not always correct.  If you feel lucky and push it enough, you will eventually get caught.  I speak from considerable experience, and consider myself lucky to be alive.  After one very memorable event of getting caught in an aircraft that was not FIKI, I went out and bought a Beech 58TC with everything.  No way I would fly any aircraft without serious FIKI capability anywhere near potential icing.

FWIW YMMV

For those of you that are smarter and better pilots than I am, good luck.

[N201MKTurbo]

The worst icing I've had was after a two hour cross country in the winter. No ice on departure or cruise, but during the approach started picking up ice. It is hard to throw in the towel when you are three minuets from landing. If you continue you have gravity on your side. If you quit you have to go up at a slower speed into the ice. It is a tough call. The siren song of a nearby airport is hard to resist. I had over an inch of mixed ice when I landed. The guy from the FSS (KCPR) walked over and gave me the stink eye. Nothing ever came of it.

[Gary0747]

The biggest problem I see but never experienced when decending through even a thin cloud layer to land even to VFR conditions is the potential for an iced over wind shield.  I doubt one would pick up much air frame in a dive through 1000 feet of clouds but not being able to see to land would be my biggest worry.   I carry a squeeze bottle of Proplene glycol that I could potentially reach out through my side vent and put some on the front wind screen to create a small view spot if that ever happened.   One other thought didn't the old DC3s routinely spray silicone on their props to help shed potential icing.  For those of us paranoid about the diving or climbing through thin cloud layers Dow Corning grease on the prop leading edge might help?

[N201MKTurbo]

You take a credit card out of your wallet, stick your arm out the storm window and scrape the ice off.

[Guitarmaster]

14 hours ago, Bob - S50 said:

Just curious.

Living in the Pacific NW, as many of you suspect, we have a few cloudy days in the winter.  Trying to go east involves climbing over an MEA of 8400' or going down to the Portland area where the MEA is 7000'.  Since I've been avoiding potential icing like the plague, it limits doing Angel Flights over to the Spokane area.  My philosophy has been, whether moderate icing is predicted or not, if a look at the skew-t doesn't indicate that I can be above the weather by the freezing level, I don't go.  I either want to be able to stay below the weather or climb through it and be on top before I get to the freezing level.

Wondering what others think.

Light icing?

Trace icing?

Time exposure during a climb/descent through the weather?

I flew freight years ago in Turbo Seneca2 and Chieftain mainly from KBFI to KGEG.  In those years, I dealt with ALOT of ice and I am intimately familiar with PNW flying.
My first reaction is don't do it.  The airplanes I were flying were FIKI.  Boots, heated windshield and props.  
The PNW, specifically the western slopes of the Cascades are huge known ice makers.  So much so, there is a FAA advisory circular on it.  
Twice I was not able to out-climb the ice accumulation WITH the boots doing their job simply because of ice weight.  Once I descended, not by choice, over the mountains with full power and 500FPM down.  the controller vectored me through Stevens Pass until I got low enough for the ice to come off.  The latter party started off at 10000ft and ended at 3800ft where the warmer air was.  There was roughly 8 inches of ice on the unprotected sections of the wing.  That amount accumulated in about 15 minutes.  I have a picture of it somewhere.
Anyway, if you HAVE to get across the mountains, do the shuttle climb.  That is to fly west, climb and cross at 9000+ feet.  This keeps you out of the worst of it USUALLY.  Again, in a non-fiki airplane, I wouldn't even bother... unless it was really cold.  Like -25c cold.  At that temp the water droplets make their own condensation nuclei and you have ice crystals which will not produce airframe icing... probably.
Escape route is PARAMOUNT.  If you shuttle climb, get into ice over the mountains, you can turn around and descend.  

On a side note, watch out for MT. Rainier + high winds.  I bent the main wing spar on a Seneca2 on V2 over the mountains one night in mountain turbulence.  130kt winds over the rocks.  I was a very lucky man that night and nearly gave up flying all together!  


 

[aviatoreb]

10 hours ago, WardHolbrook said:

Believe it or not it was 2008. Basler Aviation in Oshkosh did it. You've got to wonder how the DC-3 survived flying in all types of weather for 75 years without it.  

Sure - but that's an entirely new airplane once they refurb it and put in turbine engines.

But what does it mean regulation wise when an airplane that is 75 years old and was flying long before the word FIKI existed flies through ice?

[M20F]

10 hours ago, Loogie said:

The problem w ice is it is very difficult to evaluate the loss of performance, until you need it.  If that mooney wing is covered with 1/4" of rime ice, there is absolutely a degradation, while you might be able to hold what you have in terms of airspeed, I can guarantee that the critical angle of attack will have changed, in the wrong direction...it will also stall assymetrically and provide some non-tested flight characterstics etc.. 

And this is the real problem.  The shape of the wing changes reducing lift and increasing drag.  The weight of the aircraft increases resulting in a need for  more AOA to hold altitude.  The prop builds ice resulting in lack of thrust.  The shape of the wing changes the critical AOA.  It really starts to develop exponentially because you are playing with lift, weight, thrust, and drag for every small piece of ice you pick up.  It generally goes from everything is ok to the plane stops flying almost instantly, not gradually.  Because you cannot remove the ice you have no ability regardless of your stick and rudder skills to resolve the situation (short of pulling the chute if you have one) so you crash and die.

Lastly there  is the physical damage ice can do to the plane.  Many pay a couple $100 to dynamically balance their propellers and just a small amount of weight makes that happen.  Now imagine what happens when one blade as 2lbs of ice and the other has 5lbs of ice and what kind of stress that puts on the motor or what happens when the 2lbs flies off and the 5lbs stays.