Operational or Real World Questions about Icing

[JAHinYYC]

I am hoping to learn from the collective wisdom on these forums so I am hoping that respondents will go gentle on me for asking a rookie question.

I operate a Mooney 231 for personal use. Other than pitot heat and prop anti ice there are no icing countermeasures aboard.

I am clear that flight into known icing is prohibited.

In my limited experience I have stretched that definition to include probable icing conditions, a (non exhaustive) list of which are:

- flight into cloud when OAT is below freezing or will be transition to below freezing within the cloud (ie transition from warmer air mass to colder air mass);
- flight into forecast icing conditions;
- flight into precip when OAT is below freezing.

To date my two encounters with icing (light rime build up) have occured in cloud when the OAT was +3C. I have attributed this to probable instrument error in measuring the OAT.

I am planning a very long cross country from my home base in Alberta to Ontario in a couple of weeks. Recent weather in the area around Winnipeg and around the lakes has forecast icing between 3000 and 12000. If I cruise out I should be okay at FL150 or FL170 so long as the icing layer is not worse than forecast - but I will be hooped if I have a mechanical failure and need to decent through the icing conditions.

At the risk of asking a dumb question - my natural instinct would be to stay put and wait for things to pass, but is that overly conservative?

The reason I ask, is that I was watching a brief video on the AOPA website where the pilot was flying is C182 around the lakes during periods of light snow with similar anti icing provisions. Instinctively I thought the forecast of snow was a no go, but why would he initiate the flight if this was a solid rule?

Other than ensuring you are deiced prior to flight, when you might encounter icing, types of icing, how ice forms and general advice to stay the heck out of it - the topic wasn't covered in great depth at any level of my training or subsequent recurrency.

I would like to get smarter on this topic.

Thanks in advance for replies.

[ahramin]

Many Americans and some Canadians think it's ok to fly in light icing conditions without certified in known ice conditions. After all the definition of light icing is that it takes at least an hour to become a problem. Unfortunately you can never know when light icing will become moderate or severe with no warning. It has been demonstrated many times that you can get away with IFR in icing conditions without know ice certification for a while - sometimes years - before it kills you. Personally I don't feel this is effective risk management. My professional limits for aircraft like your Mooney are fairly simple:

No IFR within 2000 feet of the freezing level.
No flying in any frozen precip other than snow when it's cold. Cold means there is no way for the snow to melt.

For the circumstances you posted above, this means flying at an indicated temperature of 3 degrees is a NO. Remember ram air temperature rise. Don't be anywhere near freezing temperatures in cloud.

Climbing and descending through clouds above or within 2000' of the freezing level is a NO. Sooner or later you are going to encounter worse than light icing in the climb or descent and that usually has all sorts of bad stuff associated with it like death.

However flying through snow in cold conditions is a conditional yes. The problem isn't icing (you aren't going to get any), the problem is visibility. If you have good VFR vis then it's even better than flying through rain.

And if despite your best efforts you end up with some "light rime build up", admit that you have screwed up, declare an emergency, and get out of the icing conditions immediately. And remember to add 5 knots or more to your over the fence speed so you don't stall it on from 50'.

[Taco Joe]

From what I read, your go/no-go decision is a little too conservative. However, personal limits and comfort is a huge factor in determining when or when not to launch. If you don't feel comfortable doing it, don't launch as it'll only cause more problems.

As for each:

"- flight into cloud when OAT is below freezing or will be transition to below freezing within the cloud (ie transition from warmer air mass to colder air mass);"

Depends on the OAT, if it's in the -10 to +5 range and the clouds are thick (e.g. A cumulus layer), you will probably pick up ice. If it's really cold (-20 and below), you're usually okay.

"- flight into forecast icing conditions;"

Simple enough for your icing experience level. As you get more experiencd in flying in icing, you'll be able to read between the lines on the forecasts and determine if you're going to ice up or not. For example, the GFA says there's icing in a bounded area on the Icing and Turb page, if you look at the Clouds and Wx side and there forecast precip in the same bounded area...then precip is the culprit. If you look at the radar and see no precip and the METARs and TAFs also show no precip, then you're most likely not going to pick up any. But you'd have to keep an eye on the weather and have an out ready if it does start.

"- flight into precip when OAT is below freezing."

See the first response wrt OAT. As for the precip, depends on the type. If it's light dry snow, you may get some trace (a layer of bug splats on the leading edge gives a similar performance decrease, so not much). If it's heavy wet snow, freezing rain or pellets...that's a different story and you should be avoiding that.

If you really want to see what your plane can do and the effects of icing, I would suggest going up with someone who has good icing experience and if you're lucky, has time on a Mooney or similar type. May cost a bit to pay for the training, but the experience will be worth it's weight in gold.

[the_cr]

http://aircrafticing.grc.nasa.gov/courses.html

This website has two training modules developed by NASA about ground icing and icing in flight. It was made primarily for aircraft that can accept flight into known icing conditions but if you want to learn more they are a great resource.

[Colonel Sanders]

Dunno about the M20K (231 TCM TSIO-360) but the
M20J (201 Lyc 200hp IO-360) did not carry ice very
well. To deal with icing, you need power - a lot of it!
You need power to overcome the drag of the ice, and
power to climb above it. The turbocharger of your
M20K should help with power at altitude, but still, 200hp
isn't very much for that very heavy airframe.

Be careful around the great lakes. Lots of moisture
there, and it's surprising when you can pick up ice. I
picked up ice in the M20J over Lake Superior in August.

Stay the hell away from the northeast quadrant of a low.
Look at the radar animation. Any flow out of the south
is too much icing for a little airplane to handle.

Once the cold front has blown through, then you have
a chance. Flow out of the north means that the air is
dryer, and the moisture is already frozen. Snow doesn't
stick in my experience, although it can be annoying for
static. Post-cold front you get a low, thin layer that
often quickly breaks up, and even though it's below
freezing in the cloud, you can easily get on top in the
sunshine in any airplane.

[Chuck Ellsworth]

JAHinYYC I have been trying to come up with something as advice to answer your question that will not end up being taken as arrogant or ego on my part.

So here is the best advice I can give you.

After you read the weather forecasts and actual's and looked back into the past weather trend before you go anywhere at any altitude be sure there is no " Possibility " of in flight icing.......weather forecasts issue " probabilities " you want to narrow it down to " no possibility ".

. E.

[Lurch]

JAHinYYC I have been trying to come up with something as advice to answer your question that will not end up being taken as arrogant or ego on my part.


. E.

I've known JAHinYYC for quite a few years and if he can tolerate my ego and arrogance for all these years I don't think you'll hurt his feelings. That and I'm actually curious to read your non-PC reply.

Lurch

[Chuck Ellsworth]

That and I'm actually curious to read your non-PC reply.

I don't understand what you mean by non-PC ?

[JAHinYYC]

Sincere thanks to all for the time and effort they put into their replies.

The more I fly (1130hrs and counting) the more I am exposed to. When I am exposed to something I don't fully understand or have an abundance of experience with I worry and want to get better.

. I appreciate the respect and tact imbeded in your post, but Lurch is right I wouldn't have asked unless I was prepared to admit I don't have all the answers.

(He's also right that if I can withstand 1.8 in cramped quarters with him I can pretty much put up with anything. )

You guys have all gone too easy on me given the tongue lashing I was worried about receiving.

[Chuck Ellsworth]

The best indication you are a good pilot is the fact you ask quesions when you want answers.

Icing is one of the most insedious of all the dangers involved in flying because it can go from benign to uncontrollable in a very short time frame.

In light aircraft it is one of the dangers to flight that one should avoid like the plague.

[trey kule]

First of all, dont believe a word all these big pussies say..Never let fear and common sense hold you back

Seriously though

my natural instinct would be to stay put and wait for things to pass, but is that overly conservative?

If you are concerned enough to ask the question,,,my advice is stay put. The downside of that decision is you wait a few days.
The downside of launching and getting into a little bit more ice than you expected is contact with the ground..
A little ice is like being a little pregnant. Performance will deteroiate for awhile and then....did I mention the downside of flying into ice already?

From previous threads here you are going to get alot of advice from pilots who have only played with ice..When it starts building unless you have a crystal ball you simply dont know..As far as flying by this or that rule...that is OK, but when you are in the middle of nowhere, in cloud, and the ice cheats you by starting to form where it is not supposed to, makes for, at best an unpleasant journey even if things eventually work out ok...unless of course you are invulnerable or to stupid to realize the dangers.
Then, of course, it is a learning experience and cause for celebrationl.

One of the things I constantly hear from inexperienced pilots is that as soon as they see performance degradation they will exit.
That has to be one of the dumbest things I have heard. You avoid ice when you do not have a fully de iced aircraft.. Avoid it like the girlfriend when you are with your wife. ..And even if your aircraft is certified for flight into know icing (moderate) you dont go flying through it any more than you have to as a' learning experience..'

There are a few old timers posting advice on this thread..Notice a common theme amongst them You are not a sissy for being cautious.
I

Rant over..have a good trip whatever you decide.

[Colonel Sanders]

You avoid ice when you do not have a fully de iced aircraft

That's not quite true. If you keep the speed up over
300 knots, icing isn't a problem. Probably bad for the
environment, though. David Suzuki wouldn't like it.

[photofly]

Point of order: I believe the heating is due to adiabatic (isentropic) compression, not friction. Carry on.

[Big Pistons Forever]

JAHinYYC

Your airplane does not carry ice well and to be concerned about icing is to be IMO a smart pilot. The easiest way to deal with icing conditions is obviously to not be in cloud with the OAT below freezing. This is how ever pretty limiting and so I am going suggest a few alternatives.

NOTE: This is FREE internet advice and is worth exactly what you paid for it. Examine it with all the usual cautions you would take with anything you read on the internet.

When I am flying IFR I hate flying in cloud so I always try to get on top. Days with a relatively stable atmosphere and stratus type cloud formations often have a defined top. If you are flying in above freezing air in the clear and want to climb through a layer that is above the freezing level then I don't see a problem, the worst case scenario is you start picking up ice and so you have to descend back to below the freezing level.

Things get a bit harder if the freezing level goes right to the ground. In this case I see climbing from VMC conditions through a layer still an option. However you are definitely incurring additional risk. This can be some what mitigated by asking for a tops report and any evidence of icing form any aircraft nearby. Secondly avoid long climbs through a very thick deck. As a gross rule of thumb any more than 4-5000 feet of climb in cloud is too much. If the deck is thicker than that there is probably vertical developement happening and the chance of icing significantly increases. The critical thing here is that at the first sign of any icing immediately return to clear air. Icing severity tends to increase as you near the tops and so continuing the climb while accumulating ice is a very very bad idea.

The bottom line is you want to avoid any significant periods of level flight in cloud above the freezing level and if you do encounter any ice immediately do something, change altitude, or turn around.

[Colonel Sanders]

With a turbocharged Mooney, I presume that you
have a portable kevlar oxygen tank and cannullas.

I had a setup like that (except older aluminum tank)
for the M20J. Worked ok for me, except that it
won't for you.

With the convenient cannullas, you can only go up
to 18,000 feet. Your turbocharged Mooney will
actually fly up to 30,000 feet but someone here
will yell at you if you do that.

Regardless, buy an O2 mask with a microphone
so that you get up on top of the weather in the
flight levels. Some days you might even be able
to pick up a 100 knot tailwind.

If you can get up high enough, and cold enough,
with no convective activity, the moisture is going
to be frozen. Re-read the previous sentence, and
pay attention to NO CONVECTIVE ACTIVITY. Also
pay attention to my previous post about NO FLOW
OUT OF THE SOUTH.

The only problem with doing this - going very
high and very cold - is that at some point, you're
going to need to come down again. Do that as
infrequently as possible, so do the tank STC to
increase your wing fuel to 100 gallons. This will
make your airplane much faster. People don't
understand this, but making an engine more powerful
doesn't make it faster. Roy LoPresti - nice man -
understood that. What makes an airplane fast is
lots of fuel, so you don't have to make a time-consuming
fuel stop. Also, you don't have to descend through
the muck and then climb up again to the sunshine.

But even will all the fuel in the world, at some
point you will need to come down at your destination.
And sooner or later there will be a PIREP of "moderate"
icing between you and the ground.

"Moderate" icing is one of those nasty practical
jokes in aviation. "moderate" icing in a Mooney
is certain death in a matter of minutes. Ha, ha.

Flying the M20J, I had a plan formulated as to
what to do, if I got stuck up on top of a icing
layer and didn't have enough fuel to go somewhere
else. Fortunately that never happened to me,
but I want you to think about what your plan
will be, if that ever happens to you.

I will post my plan after a bit, to allow for some
discussion.

[Colonel Sanders]

Scenario clarification:

You arrive at your destination in your Mooney, on top
of a solid layer. Unfortunately when you do, you discover
that there is a widespread area of icing in cloud which
extends from 200 AGL to 10,000 AGL. Due to really
bad decision making on your part, and a complete lack
of situational awareness, you do not have enough fuel
to fly someplace else with different weather.

Sooner or later you're doing to have to descend through
that 10,000 foot layer of icing in your Mooney, which
doesn't carry ice worth beans. They were built in Texas,
after all, which is hotter than Hell.

How do you do it? Hint: not like ATC will want you to.

[photofly]

I will post my plan after a bit, to allow for some
discussion.

But you're used to wearing a parachute. I think that's cheating.

[Colonel Sanders]

Nice try, but no.

[photofly]

How do you do it? Hint: not like ATC will want you to.

All right then.

Does it involve a vertical downline below 1000 agl?

Oh wait, how about putting it into a spin?

[Colonel Sanders]

Given that the bottom of the cloud base is 200 AGL
it probably involves flying an ILS at some point.

A Mooney is not a good spin machine. For the
purposes of discussion a Bonanza, Debonair or
Comanche are equivalent.

[photofly]

A Mooney is not a good spin machine.

Nobody said the spin had to be upright.

Does it have anything to do with the falling leaf exercise?

[Big Pistons Forever]

CS raises a very good point which I inadvertently edited out when I made my earlier post. That line said If you want to climb through clouds above the freezing level you should be flying towards VFR weather. This may involve a considerable detour as the good weather may not be in the direction you want to go.

However as CS pointed out there is a risk the forecast may be wrong and you get stuck on top. The only defense is to carry lots of gas and be vigilant in monitoring the enroute weather and change the plan or get down below the clouds as soon as it looks like conditions are changing. However to be going to towards forecast VFR and then arriving and finding you have to descend through moderate icing to the ILS suggest that you have passively let a deteriorating situation develop and speaks more to poor PDM in general not just dealing with icing conditions.

However I would like to reiterate that the safest way to fly is to just stay out of clouds that are above the freezing level. The only point of my earlier post was to offer an alternative strategy which could allow a flight to be completed that other wise would not be possible, and again in my own personal opinion, without incurring an excessive amount of additional risk. But there is no question that the risks on that flight will have increased and those risks need to be aggressively managed both as part of pre flight planning and throughout the flight

[JAHinYYC]

How do you do it? Hint: not like ATC will want you to.

I am assuming messing my pants and having a good cry is not one of the options?

[2550]

O boy....I can hardly wait to hear cs s escape from certain mooney death. My best plan would be a very long, straight in high speed (power up, clean) ILS, followed by a flaps up landing....straight in from above the tops tho would mean about thirty miles tho.

If you were really on mb you could make a steeper decent and intercept the glidepath closer in. A steep decent and tight procedure turn, or intercepting the glide path from above might work, but that sounds too challenging for me. Especialy with dirty pants already.

[Colonel Sanders]

intercepting the glide path from above

Careful about that.

(getting stuck on top of moderate icing) speaks more to poor PDM

Hey, stuff happens. And when it does, you'd better have
a plan to deal with it.

high-speed straight-in ILS ...thirty miles

Now you're starting to think. However, even at 3nm/min
that's still 10 minutes (!!) in moderate icing. You can do
better than that.