Icing
 

I am a low time private/insturment pilot, commercial student. I have scowered forums, and NTSB rulings, and dont have a good idea of how to apply the definitinos of "known icing conditions" or "forecast icing conditions." My question pertains to GA winter flying.

Also if there are multiple threads on this topic already please simply direct me there. I didnt see them while using the search for APC.

so some questions (all pertain to a GA aircraft with simply pitot heat):

1) Can I legally fly into a cloud with an OAT of -3? (some NTSB rulings seem to use this condition as known icing conditions)

2) Can I takeoff with an icing airmet surface to 10000. (ceiling off say 7000 with no precipitation in the forecast if I stay VFR)
a) if I do and it starts to precip, am I now open to scrutiny if something would happen?
(icing airmet and visible moisture)


3) I see pireps from c-172's (assumed not certified for Flight into Icing) reporting rime icing with freezing OAT. Are they reporting that they are in violation?

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DISCLAIMER: There is a big difference between legal and safe as far as this topic goes. I'm going to discuss legal, which is often NOT safe.


Forecast icing is not "Known Icing"...legally you can fly into that area (not a good idea of course).

Environmental conditions such as a certain temperature have never counted as "known icing" to my knowledge...even in the airline biz temp/moisture combinations are referred to as "conditions conducive to icing".

The gold-standard definition of known icing is actual ice observed at the flight altitude...this almost always requires a PIREP. A METAR from a nearby mountain top observatory, or a freezing rain report on the ground would qualify also. Again it has to be actual ice reported (of any type), not moisture/temp.

Also if YOU encounter icing in flight, then that immedaitely becomes "known icing" and you need to get out of it (obviously).

EDIT: Looks like Fatty and I have different answers on this one...I'll do some research if I have time. His answer is definately the safest answer, if not the legal answer. Also the FAA could charge you with violating 91.13 if you do anything which they don't think was a great idea...even if it is not a violation of other regs.

Now I'm confused :o
It sounds like you're (or the book really) is saying that you couldn't fly on a clear, cold day is the temperature fell inside the range above; or are you saying that he could not fly into clouds under those conditions (which I would understand). If in a temperature range that supports the formation of ice and visible moisture is regarded as "known icing", what constitues "forecasted icing"? The temperature is expected to fall to something within the range and clouds are expected to form?
Good questions sellener. I look forward to hearing the information provided by our smart group here on the forum.

USMCFLYR

The AIM in 7-1-22 (b) states "A pilot can expect icing when flying in visible precipitation, such as rain or cloud droplets, and the temperature is between +02 and -10 degrees Celsius..." This definition has been used in NTSB and court cases to define "known icing conditions". Even though the AIM is not regulatory, it has a tendency at times to become regulatory in hearings. You can also check 7-1-23 in the AIM for the FAA's definition of known and potential icing conditions.

EDIT: This applies to subpart F of Part 91 - Large and Turbine Powered Multiengine Airplanes: This leads to the FAR under part 91, 91.527 Operating in icing conditions. 91.527 (b) says no pilot may fly under IFR conditions into known or forecast moderate icing conditions or under VFR into known light or moderate icing conditions unless the aircraft has the appropriate de-icing and/or anti-icing protection equipment and is certified for icing conditions. 91.527 (c) basically says you can't fly into known or forecast severe icing conditions unless the aircraft has appropriate equipment and is certified.

I will do a search of the NTSB and FAA sites to see how they have applied the regs. I thought there was a reg somewhere other than 91.13 about not flying an aircraft other than in accordance with it's operating limitations...

Here's the FAA advisory circular on icing:

http://rgl.faa.gov/Regulatory_and_Gu...C%2091-74A.pdf

As a sidenote way back when I flew checks in 210's with boots, the forecasters would predict light to moderate icing in the clouds anytime the temp was 32 or colder. There were very few times icing was actually encountered so I'm sure the forecasters were just covering thier dupa. If we didn't take off because of a forecast of ice we would have never flown IFR in the winter.

Another note. I remember holding @ Bojak @ 3000 going into MDW waiting for the runways to be cleared. Never picked up any ice. I was the first one in before the 737's. When I landed I was asked for a braking report and said "fair to good". It was actually pretty good but I didn't want to be responsible for a bigger bird having problems braking.

When I got on the ground nobody was taking off and I had over 1/8 inch clear ice all over the plane before finishing taxiing in. Um, temp inversion????

I should also make myself more clear. In the above scenario the plane was EQUIPPED FOR ICING. If I was in a plane not eqipped for icing in that case I would not have tried flying IFR.

Pirep is the best option for knowing if there is ice. If I look at winds aloft and see -01, I would still go flying because it's not really accurate. If the control tower says that a person reports icing or a pirep reports icing, then I won't go flying.

From the ice AC listed above:

"Forecast Icing Conditions. Environmental conditions expected by a NWS or an FAA-approved weather provider to be conducive to the formation of in-flight icing on aircraft.

“Known icing conditions,” as defined in the AIM, are conditions in which ice is observed or detected in flight, by your aircraft or another aircraft, or an airport."

Since the AC is put out by the FAA, and not some guy who wrote a book, I'd tend to lend it more credibility. That AC had some good stuff in it. Anyone who pilots light aircraft in the winter should be familiar with it.

I guess I'm trying to figure out the spirit of this thread. Does the OP want to go up during the winter and get some actual instrument time. Again there are differences like rickair states between legal and safe.

I operated non-icing aircraft in the winter for many years instructing. There was no reason to go out on a hard IFR day when it was below freezing hence the visible moisture and below freezing temps made a pretty good recipe for picking up icing. Now that didn't bar me from getting my students actual IFR experience. All I needed was weather that would allow me a way out - ceilings higher than MVA, MEA. In which case I would file a block of airspace with an block of altitude that would allow me to enter and exit the clouds at my leisure. Hop up in the clouds, get no ice, great. Start picking up a slightest amount get out quickly and easily. I had this discussion with our FSDO rep and he had no problem with this.

Again I don't know for sure what the OP wants out of these questions but there are very few legal and very few safe ways to get actual IFR in the winter in a not certified for icing aircraft.

Currect me if i'm wrong, but doesn't that FAR fall under Subpart F: Large and turbine-powerd Multiengine airplanes and fractional Owenership Program?

aahhgg! You are correct. I'm out on a trip and just did a search of the FAA regs database and didn't check the section. I remember that reg from my corporate days. However, I have read something else. I will have to find it. In the meantime I'll edit my first post...

Ok. Here is the info from the advisory circular from a regulatory point-of-view for general part 91 operation:

"d. Aircraft Not Certificated for Flight in Icing Conditions.

(1) Aircraft certificated since the mid-1970s that are not certificated for flight in icing conditions will have a limitation in the AFM or POH and possibly a placard on the aircraft stating that flight into “known icing conditions” is prohibited. “Known icing conditions,” as defined in the AIM, are conditions in which ice is observed or detected in flight, by your aircraft or another aircraft, or an airport. Such limitations are binding under § 91.9, Civil aircraft flight manual, marking, and placard requirements, and this regulation takes precedence over §§ 91.527 and 135.227. However, if a pilot of such an airplane were to takeoff and fly in area in which icing is forecast (e.g., AIRMET Zulu), it is expected the pilot will through preflight planning and in-flight execution:

(a) First attempt to avoid areas of “potential icing conditions”, which are areas of visible moisture such as clouds at temperatures below freezing;

(b) If that is not practical, attempt to avoid areas of forecast icing by all tools available (e.g., AIRMETs, SIGMETs, CIP and FIP); and

(c) If icing is encountered, declare an emergency and exit the conditions immediately.

NOTE: Failure to follow the section above may result in enforcement action under § 91.103, Preflight action, or § 91.13, Careless or reckless operation, depending on the circumstances and the actions a reasonable pilot will take."

As stated above AC 91-74A is a good read.

In regards to the spirit of the thread...... I have made a personal choice never to fly my un-equipped aircraft intentinally into visible precipitation when the temp is close to freezing or below. That obviously limits my winter GA flying. However, I was trying to gain a technical/legal understanding of what is or is not legal in the eyes of the FAA regarding unequipped aircaft flying in known/forecast icing conditions.


I obviously understand you can't legally fly into known icing conditions. One of my problems is I cant nail down a definition of known icing conditions. I realized just now as Im typing perhaps my hangup rests in bowersbum's post. The NTSB has in some cases to the best of my knowledge used, the AIM 7-1-21 (b) (im using an 08 version so that might be the difference between browersbum's AIM (7-1-22 b) to define known icing conditions. If that is true I would have to be prudent and just use the more restrictive definition. Which would compliment my decision to not fly in cold clouds/visible precip.

ok, so in my own head, I can live with what I believe to be the NTSB's definiton/interpertation of known icing.... temps 2 to -10 in visiable moisture. My next question involves flying that same unequipped aircraft on a precipitation free day clear of clouds while an icing airmet is issued for surface to 10 covering all of michigan (where i fly). Can I legally fly? Just the other day Im looking outside at scattered clouds 4000-5000, while an icing airmet is out for surface to 10. Am I legal to fly? If not there certainly are a lot of illegals flying around :)

I know GA flying is limited to some extent in the winter but If I cant fly with an icing airmet out, while staying clear of clouds/moisture, I cant fly in the winter period. Theres always an airmet covering michigan in the winter! All responses, apprecitiated as always.

So if I'm reading that right and follow step A. I can fly clear of clouds and visible moisture temp below 2 - -10 with an airmet in effect, right?

ok I think this is the last what-if... Im now flying clear of visible moisture in a temp of 2 to -10 with an airmet in effect. So far, I believe this to be legal. Im flying Lansing to Grand Rapids. Grand Rapids has a TAF out forecasting light snow showers and I land there. Was that just a forecast icing condition i just landed in and in doing so did I just violate the AC bowersbum posted (paragraph b)

AC No: 91-74A
 

Part 91 Icing Regulations.
a.
IFR. No pilot may fly an airplane under IFR into known or forecast moderate icing conditions unless one or more of the following apply:
(1)
The aircraft has ice protection provisions that meet the requirements in 14 CFR part 135, appendix A, paragraph 34 of Special Federal Aviation Regulation (SFAR) No. 23.
(2)
The aircraft has ice protection provisions that meet the requirements for transport category airplane type certification.
(3)
The aircraft has functioning deicing or anti-icing equipment protecting each propeller, windshield, wing, stabilizing surface, control surface, airspeed instrument, altimeter, rate of climb instrument, and flight attitude instrument system.
b.
VFR. No pilot may fly an airplane under VFR into known light or moderate icing conditions unless one or more of the following apply:
(1)
The aircraft has ice protection provisions that meet the requirements in SFAR 23 paragraph 34 (same as part 135, appendix A, paragraph 34, and § 23.1419 at Amendment 23-14).
(2)
The aircraft has ice protection provisions that meet the requirements for transport category airplane type certification.
(3)
The aircraft has functioning deicing or anti-icing equipment protecting each propeller, windshield, wing, stabilizing surface vertical tail, control surface flap, aileron, elevator, airspeed instrument, altimeter, rate of climb instrument, and flight attitude instrument system.




To answer the OP's question, Can I legally fly into a cloud with an OAT of -3?

Based on the AC 91-74A, YES, but only if the icing wasn't forecasted or known to be moderate (AIRMET) and you filed IFR. If you filed VFR, well, you're in violation as soon as you flew into the clouds.

But, as some have mentioned, and the author of the book I first quoted suggested, according to many FAA and NTSB reports, the FAA has drawn a very fine line between KNOWN and FORECASTED ICING.

2) Can I takeoff with an icing airmet surface to 10000. (ceiling off say 7000 with no precipitation in the forecast if I stay VFR)
a) if I do and it starts to precip, am I now open to scrutiny if something would happen?
(icing airmet and visible moisture) If you filed IFR, NO. You can't fly into an area of known or forecasted icing. VFR, yes, if you obey cloud clearance requirements for the specific class of airspace.

3) I see pireps from c-172's (assumed not certified for Flight into Icing) reporting rime icing with freezing OAT. Are they reporting that they are in violation?

If they were filed VFR, yes. IFR, maybe (was there forecasted or known reports of icing).

DISCLAIMER ... this is the best I could come up with. I'm sure there are others that are smarter than me or have better gouge. The above references came from the AC No: 91-74A circular.

"If you filed VFR, well, you're in violation as soon as you flew into the clouds."

Well, if your filed VFR and fly in the clouds, you got bigger problems with the FAA than possibly running into ice....

I think the VFR subparagraph has more to do with flying under freezing rain in VMC or something like that.

sellener, I think you are being way too literal, although a lot of that is the FAA's fault i the way it defines "known ice". But, no, you are not going to encounter ice in visual conditions, even if there is an Airmet for icing in clouds and in precipitation.

The FAA's AC is giving you a set of guidelines and examples of the types of conditions that are conducive to icing. The only significant one outside of clouds is freezing rain (although snow might be an issue in limited circumstances).

The legal standard for violations is even looser - if you flew into conditions that a pilot should have known knew was conducive to icing conditions - even if there was no PIREP for the immediate area or specific icing forecast - you can be found in violation.

Here's an example of how loose the standard can be: http://ntsb.gov/alj/alj/O_n_O/docs/aviation/5154.PDF

A violation often comes down to: if you land with ice on your wings or cause a problem because you actually encounter ice, the chances are you flew into known icing conditions.

Icing is one of those great catch 22's in flying. It's easy to get sucked in, and it does take awhile to really "learn" to fly, handle, and know where icing is. If you have the opportunity, try and get a "ride" with some 135 freight guys, because that's where you're going to learn about it, especially right now, it's prime time for icing!!!!!!!!!

Just wanted to acknowledge I realize I am beating a dead horse, and being quite literal. Also appreciate everyones time and info.

Im asking myself right now if I would fly with a student VFR with weather we have right now in mid michigan. Icing airmet surface and up. Forecast snow showers in the area forecast and TAF. No visible precipitation out the window BKN clouds 5000?

My concern would be if I encountered snow, wet snow or freezing rain and landed, and someone tattled. I could hear the FAA saying... Stupid pilot you flew in an icing airmet with forecast precip, heres your violation.

Also if you were up in those conditions and simply encountered a cold light snow shower would you immediately terminate the flight?

If any freight guys in mid-michigan want to give a ride to a motivated student let me know. I have a steady hand for pouring coffee.

You are exactly correct. You can still be VFR and enter icing; freezing fog, freezing drizzle, freezing rain and snow etc.

The regulation seems to be written so if you filed VFR, you could fly through an area with forecasted light to moderate icing. But as soon as that ice becomes known, if you willingly flew through the area, you would be in violation. As others have pointed out, the FAA has been very liberal when determining known and forecasted and whether the pilot was wreckless.

Does that make sense? Am I missing anything?

Sellener;

I believe you would be legal if you flew with a student, VFR, in an area of FORECASTED light to moderate icing (assuming your aircraft isn't certified). But the minute the area gets KNOWN icing, you need to exit that area.

Whatever the case, READ APPENDIX 2 of that advisory circular. Even the FAA admits, forecasting ice is difficult and many pilots suddenly find themselves unknowingly in a bad situation. As PIC, you have to make the decision if its "smart" to go fly. If you think you can maintain wings etc clear of ice, then go for it. But if theres chances of you having to penetrate clouds or freezing precip, I wouldn't go. Being legal does you no good if you're dead.

-Fatty

"Im asking myself right now if I would fly with a student VFR with weather we have right now in mid michigan."

I'd have no problem with it.

I've flown in snow showers and the main problem is greatly reduced vis. Have you flown in rain showers? Snow is about twice as bad.

Go ahead and do your training flights. I'd just keep a close eye on the precip and give always make sure you have an out. Stick around areas that have a a nearby airport in every direction so if the weather pushes you one way you still have a place to go.

I agree.

The problem with freezing rain is that the droplets freeze on contact, icing the aircraft. Other types of frozen precipitation generallydon't do this. The problem cones up with the "generally" but that's where knowledge of the weather conditions in your locale make a difference.

I know that's a common belief, but I don't think it's right - not the need to get out part, but the difference between "known" and "forecast."

The best way I've heard it put is that it's "known (icing conditions)" not "(known icing) conditions."

IOW, the way the enforcement cases read, all you have to know is that conditions conducive to icing exist - and forecasts are certainly enough for that. If there was a forecast of the "right" temperature and clouds, for example, you "know" that "icing conditions" exist, and that's enough to hang you if you have an ice problem.

http://www.genebenson.com/docs/icing...n_april_07.pdf


The whole icing thing is nagging me and I spent hours researching it. Yeah.... Im still a nerd.

If you read the article above, the last paragraph that starts with "Ultimately......." sums up the FAA clarification letter to AOPA. Although it doesn't clarify anything.

I believe (according to the FAA) you can still fly into visible moisture at freezing and still be legal, so long as nothing goes wrong, and a prudent pilot doesnt reasonably assume that ice will stick to the wing...(airmets,sigmets,composite information).


I dont know how someone decides if ice will stick to a wing or not (composite information per the FAA) LOL

So my personal choice is to stay clear clouds, rain, and freezing rain with temps below freezing.


My only question/comment is again regards to snow. It is visible moisture. However, I could argue that based on weather theory that a prudent pilot could not reasonably assume (after checking the TAFS and FA that only snow showers were forecast or observed....no mixed rain/snow) that flight into a snow shower would cause icing.


So if theres good VFR with just scattered light snow showers, i am flying. HA Stupid FAA Jerks

Looking back through the posts, I'm surprised no one talked about the 2006 FAA Chief Counsel opinion that really stirred up a hornets' nest. So much so that the FAA took the unusual step of talking about in in the Federal Register.

As long as you're a nerd about this subject, check this out

http://frwebgate3.access.gpo.gov/cgi...ction=retrieve

I don't know why, but I've never had snow stick to the wings in VMC. Maybe it was always too dry.

The FAA rescinded the letter stating high humidity constituted "known icing" a couple months ago.