Known iceing definition?

[USMCmech]

OK folks, aparently ther are several different ways pilots/dispatchers/FSDOs define "known icing conditions". The Caravan is certified for known ice, so I don't worry to much about it, but I'm still curious.

What's the reall scoop?


I was taught that known ice is anytime ice is "forecast or reported" only.

However I have heard some people go as far as saying IMC below 32 is known ice.

Clearly there is much confusion on this issue. I have flown in plenty of subfreezing IMC without a single flake of ice, and I have picked up ice in VFR conditions. The unknow variable of moisture content is not easily measured by us pilots.

This is clearly not a subject that we can make a simple blanket statement.


RE: de icing equipment

If you want to fly your "anti ice" equiped airplane in conditions where ice MIGHT form, then you are useing it for what it was designed for. If you launch into conditions where ice is "reported or forecast" then you are gambleing that the equipment can keep up. No thanks.

However, even when "deice" equipment which is certified for known ice is used, it can still be overwhelmed by mother nature.

[NJA_Capt]

Originally Posted by USMCmech

However I have heard some people go as far as saying IMC below 32 is known ice.

This is clearly not a subject that we can make a simple blanket statement.

This is why the blanket statement is needed. Ice can form below 10C and visible moisture. VM loosely defined as IMC. Most aircraft "certified" for flight in icing conditions use this definition to direct the use of that equipment. It doesn't mean that you will get ice every time and you never know beforehand that you won't. By using the broadest definition you are adhering to the most safe and legal interpretation.

If you know that ice is probable, then you know you are flying into icing conditions. Forecast or not........91.13

[USMCmech]

Ok, but if you take the view that anytime ice is POSSIBLE, that constitutes "known iceing" then that means that every IFR flight is illeagel, unless your airplane is approved for know iceing.

Thats liks saying since there are landmines somewhere in South Korea, you should never set foot in the entire country.

[NJA_Capt]

If you are flying a "non-certified" aircraft in IMC with temps below the freezing level, I would interpret that as flying in "know icing" conditions. Because you can reasonably assume that icing CAN exist under those conditions.

You can go for a walk on a live range. It doesn't mean that you will get hit. But you can reasonably assume that there is a good chance.

[B767Driver]

Originally Posted by USMCmech

OK folks, aparently ther are several different ways pilots/dispatchers/FSDOs define "known icing conditions". The Caravan is certified for known ice, so I don't worry to much about it, but I'm still curious.

What's the reall scoop?


I was taught that known ice is anytime ice is "forecast or reported" only.

However I have heard some people go as far as saying IMC below 32 is known ice.

Clearly there is much confusion on this issue. I have flown in plenty of subfreezing IMC without a single flake of ice, and I have picked up ice in VFR conditions. The unknow variable of moisture content is not easily measured by us pilots.

This is clearly not a subject that we can make a simple blanket statement.


RE: de icing equipment

If you want to fly your "anti ice" equiped airplane in conditions where ice MIGHT form, then you are useing it for what it was designed for. If you launch into conditions where ice is "reported or forecast" then you are gambleing that the equipment can keep up. No thanks.

However, even when "deice" equipment which is certified for known ice is used, it can still be overwhelmed by mother nature.

The FAA interpretation is that flight in visible moisture (clouds, rain, etc) in temps at or below freezing in considered icing conditions regardless of icing forecasts or pireps.

[USMCmech]

Originally Posted by B767Driver

The FAA interpretation is that flight in visible moisture (clouds, rain, etc) in temps at or below freezing in considered icing conditions regardless of icing forecasts or pireps.

Reference please.


I had heard that some FSDO came out with that decision, but it was overruled by HQ. Since that would effectively limit 90% of light airplanes to VFR when below freezing.


I'm not trying to be smarta$$, I honestly haven't seen any official word one way or the other.

[B767Driver]

Here's a good article.

http://www.ifr-magazine.com/defining...n_faa_ifr.html

[B767Driver]

Here's the letter of interp.

http://www.genebenson.com/docs/icing_exp.pdf

[USMCmech]

Originally Posted by B767Driver

Here's the letter of interp.

http://www.genebenson.com/docs/icing_exp.pdf

That clears it up, thanks.

When did the FAA adopt this interpertaion?



However, what the heck do IFR pilots do durring the winter? Fly anyway and hope they don't get busted? Scud Run, and expose yourself to even more risk?

The FAA has basicly made 90% of piston GA IFR illeagel. Including plenty of 135 operators flying piston aircraft.

Serious overkill on the FAAs part IMHO.

[B767Driver]

Originally Posted by USMCmech

That clears it up, thanks.

When did the FAA adopt this interpertaion?



However, what the heck do IFR pilots do durring the winter? Fly anyway and hope they don't get busted? Scud Run, and expose yourself to even more risk?

The FAA has basicly made 90% of GA IFR illeagel.

Serious overkill on the FAAs part IMHO.

This has been around since I was a CFI in 1990.

Interestingly enough, when I was flying freight in light twins (non ice cert.)...we flew in icing conditions every night, all the time, and the FAA looked the other way. It's my understanding that the POI for the certificate holder did not enforce this interpretation, and went by a different interpretation. The FAA supervision there basically stated that since icing is such a nebulous phenomenon and difficult to forecast...icing conditions did not exist until you were accumulating ice. I'm not sure what politics are involved in making this interpretation.

It is definitely not in line with what the FAA at large considers "icing conditions".

Maybe some of the current freight guys out there can expand upon the guidance they are receiving from their companies regarding this.

[USMCmech]

Originally Posted by B767Driver

This has been around since I was a CFI in 1990.

I got my inst rating in 2002 and was taught "reported or forecast".

Originally Posted by B767Driver

The FAA supervision there basically stated that since icing is such a nebulous phenomenon and difficult to forecast

That at least is more in line with reality



THe FAA has done a poor job comunicating their interpertation to pilots out there.

[B767Driver]

Personally, I don't think a non ice certified airplane has any business being in the clouds below the freezing level. The icing forecast business is not very accurate. There may be no ice in the clouds for several hundred miles...then all of a sudden a very narrow channel of ice...then gone again. You just don't know where it is. The only sure thing a pilot knows is that if the temperature is below freezing you might encounter ice.

I flew in enough ice in light twins to see some pretty crazy stuff...full power to maintain blue line on final approach, windshields completely glazed over because the alcohol ran out or the heated patch could not keep up, tip tanks completely balled up in ice, engine induction ports iced over, etc.

When you invite an enthusiast into these kinds of conditions with marginal de-ice equipment or non at all...it is not a good recipe for success.

[NJA_Capt]

In explaining their definition of known ice, Loretta E. Alkalay, FAA Regional Counsel, referenced Administrator v. Curtis, NTSB Order No. EA-5154 (April 29, 2005). Here, the court ruled that conditions conducive to icing exists whenever near- or below-freezing temperatures and moisture exist together in a given area. It didn't matter that there were no reports or forecasts of icing conditions at any altitude anywhere near the route of flight.

The Regional Counsel's office also referenced Administrator v. Groszer, NTSB Order No. EA-3770 (January 5, 1993), which ruled that the threat of ice need not cover the entire area at all altitudes for the threat to be known or dangerous. In short, the FAA defines known ice as any visible moisture (cloud or limiting visibility due to moisture) with temperatures at or near freezing. If you go there in a non-known-ice-certified aircraft, you are in violation. Period.

The Regional Counsel's letter to me clarified the definition of known ice. You cannot legally fly a non-known-ice-certified airplane into any cloud near or below zero degrees C or you are in violation. If the FAA learns, either by direct observation or via a filed complaint, that a non-known-ice-certified aircraft entered a freezing cloud, it will initiate the EDT process and an enforcement may, or may not, result.

http://www.ifr-magazine.com/defining...n_faa_ifr.html

---------------------------------------

Pilots should also remain aware that 14 CFR Sec. 91.13(a) prohibits the operation of an aircraft for the purpose of air navigation in a careless or reckless manner so as to endanger the life
or property of another. Meteorological information that does not evidence known icing conditions, or the extent thereof, may regardless support a finding that a pilot's operation under the circumstances was careless.

This response constitutes an interpretation of the Chief Counsel's Office and was coordinated with the FAA's Flight Standards Service.

Issued in Washington, DC, on March 27, 2007.
Rebecca MacPherson,
Assistant Chief Counsel for Regulations.
[FR Doc. 07-1620 Filed 4-2-07; 8:45 am]
http://a257.g.akamaitech.net/7/257/2...07/07-1620.htm

[NJA_Capt]

Originally Posted by USMCmech

I got my inst rating in 2002 and was taught "reported or forecast".

The FAA has done a poor job communicating their interpretation to pilots out there.

I would say the FAA has done a fine job of communicating their point. It is the pilots that have a problem accepting their point of view. I as I have stated in other posts, people who fly "certified" aircraft (professionally) know the rules. It's the non-certified/ avg GA pilots that don't seem to know anything about it.

I am curious if your instrument training was civilian or military? If civilian, did the instructor have any practical experience in ice or just "reading the book?"

[USMCmech]

Originally Posted by NJA_Capt

I would say the FAA has done a fine job of communicating their point. It is the pilots that have a problem accepting their point of view. I as I have stated in other posts, people who fly "certified" aircraft (professionally) know the rules. It's the non-certified/ avg GA pilots that don't seem to know anything about it.

I am curious if your instrument training was civilian or military? If civilian, did the instructor have any practical experience in ice or just "reading the book?"

My inst training was done at a LARGE 141 school, you can look at one of their adds up and to the right. The senior instructors all had plenty of experiance.

I have been flying for 10 years, and have only heard this different interpertaion within the past year. Anyway professional pilots don't need to know about the rules for non certified aircraft, it is the weekend wariors who are flying these aircraft.

If the FAA is going to make a rule, then it needs to be enforced, not ignore tens of thousands of obvious violations per year.

These court decisions (where the FAA was the plantiff) take a "you can never be too safe" logic. I for one do not agree. Flying is never "safe" and pilots, not lawyers, are the ones in the best situation to make a decision based on the risks. Piston pilots are certianlly within thier rights making a risk vs cost decision considering their exposure and the cost of equipment.

[NJA_Capt]

Originally Posted by USMCmech

I for one do not agree....Piston pilots are certainly within their rights making a risk vs cost decision considering their exposure and the cost of equipment.

So, the piston pilots, whom you noted are not familiar with the icing guidelines, are in the best position to judge what is safe???
It is this cavalier attitude that gets widows and lawyers involved in the first place. It is not a "right" to fly. Just as it is not a "right" to disregard a reg/AC because you happen to disagree with it.

You may choose to disregard it if you wish. But you cannot say the guidance wasn't out there. I think it should be enforced also.

[MidlifeFlyer]

The legal definition of known icing conditions as "knowledge of weather conditions that are conducive to icing occurring" has been with us for a long time and is not about to go away. It's like a lot of these types of rules - it's tough to make one that has flexibility in covering the safety issue that the FAA wants to cover.

I have heard, but cannot verify, that FAA enforcement takes a practical approach to the issue by not prosecuting for flight in known icing conditions unless the aircraft in fact picks up ice and a problem occurs.

Looking back, I don't recall anyone talking about a decision where a pilot flew though clouds at with ambient temperatures of 0 to -10C, picked up no ice, had an uneventful landing and was nevertheless prosecuted.

On the other hand, there are cases where the weather conditions were obviously conducive to icing (although nor specifically PIREP'd or forecast as such) and the pilot flying through it had a problem.

Whether as a matter of policy or luck, it apperas that if you fly an aircraft with a limitation that prohibits flight in known icing conditions, pick up ice, and have a problem, you have a very good chance of looking at some enforcement action.

BTW, I agree with USMCmech's view that

Piston pilots are certainly within their rights making a risk vs cost decision considering their exposure and the cost of equipment.

Of course, there are also consequences for exercising those rights, whether handed out my Mother Nature or the FAA. Just part of the "cost" part of that risk analysis decision.