Morgan3820
En-Route
Does a forecast for trace ice qualify as ‘known ice’?
Icing
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Tantalum
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You really don't want to play any games with ice. Legal answer of "yes" aside.. if there's any kind of ice in the forecast and you're not FIKI it's best to stay on the ground.
Deeper question:
If you're flying along in IMC (no forecast ice).. but lo and behold you pick up ice.. at what point does continuing to fly in that become "flight into known ice" ..? Let's say you ask ATC for lower to be out of the clouds but they can't give it to you for 10 minutes.. are you flying "illegally" at that point? I've heard stories of people pressing into ice because it wasn't forecast so it's not "known ice" and hence "okay" <- sounds crazy to me.
Deeper question:
If you're flying along in IMC (no forecast ice).. but lo and behold you pick up ice.. at what point does continuing to fly in that become "flight into known ice" ..? Let's say you ask ATC for lower to be out of the clouds but they can't give it to you for 10 minutes.. are you flying "illegally" at that point? I've heard stories of people pressing into ice because it wasn't forecast so it's not "known ice" and hence "okay" <- sounds crazy to me.
midwestpa24
Final Approach
Even with a FIKI aircraft, you should not continue in the ice. FIKI is to get you through the ice, not hang out in it. Thats why you see even FIKI aircraft get in trouble, pilots think its a silver bullet to ice. Its time to climb, descend, or do something to get out of it.
Are you seeing forecasts of trace icing? Around here, it seems like the FAA stopped including anything less than moderate icing forecasts in their briefings. I noticed this change many years ago.
Tantalum
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Sure, but at least you're assured some safety if you need to climb or descend through a layer.. or in the case where, short of declaring an emergency, you are either terrain, or limited by other factors.. say an MEA that keeps you in the ice and tops that are beyond either you, O2, or your plane's capabilities
Out of curiosity, have there been accidents where TKS equipped planes have been overcome with ice? I know boot planes have come down.. but what about TKS? Outside of Cirrus, this seems to be the preferred choice now in Mooney, Kodiak, and going as far back as WW2 bombers. Seems like, if the pumps work and you have fluid, you get a more chemically guaranteed removal of ice, with some flowback protection as well. I've heard rumors of thermal systems refreezing just behind the thermal strip..
midwestpa24
Final Approach
Even in that situation, you still need to be looking for an escape. Can't climb out, can't descend out, turn around. What was your Plan B? There should always be a Plan B, especially when dealing with IMC and ice. I wouldn't just continue on for any appreciable amount of time, depending on de-icing systems to take care of it.
TKS does have its advantages as you noted. The biggest disadvantage to me is that the fluid is a finite resource. For example, I've been told the system on the Caravan last about 90 minutes on low, and 20 minutes on high. If you are having to use the system on high you have better be figuring out a solution fast.
The biggest difference in FIKI versus non-FIKI is in the go/no-go decision. FIKI allows you a little more wiggle room in the Go decision, but once encountering ice you should follow the same procedures to exit the ice whether FIKI or non-FIKI. I wouldn't be surprised to find out the number of ice related accidents is close to equal between equipped and non equipped aircraft.
Tantalum
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this would be a very interesting stat to find, I believe @wanttaja is our local accident data repository expert.. maybe he has some insight?
Wow.. I had no idea the Caravan was that low... that's honestly borderline useless, 20 minutes on high? Below is a picture I grabbed in the Cirrus the other day, assuming you depart with full tanks (which, I always do, if I anticipate any kind of ice) you still get almost 40 minutes of "oh **** we're going to die" ice protection on max, when the TKS, if you run it on the ground, is basically pouring out of the wings... over an hour on high.. and well over 2 hrs on norm. Granted.. "norm" is a bare minimum that intermittently soaks the wing, and is mainly good if your bouncing in and out of tops with occasional ice, or anticipate ice ahead and want to get a coating on the wing. For any actual sustained ice I run on high..
That's where the ADM part comes in though.. if you anticipate to be out of the clouds / ice / different MEA / etc., in a reasonably short amount of time I don't see an issue with pressing on. If, however, you're going to be stuck in that soup for any extended period of time, well, in that case, your whole preflight planning is drawn into question..
I agree with you by the way, people with FIKI shouldn't willy nilly fly around in the ice just because they "can" - but I think there is some nuance to it and it affords you some flexibility that a non FIKI plane would not
I don’t know about accidents but I know a guy who came really close to being a statistic with TKS. He ended up in unforecast ice with no outs and one chance at an approach at the nearest airport he could get to. This is a guy who flys professionally and has a far more conservative approach than most of the posters here seem to, so it can happen.
Tantalum
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Any more details what he was flying and what happened? Others may learn from it.. what made him almost crash?
The worst "almost" story I heard came in two flavors:
Guy shooting the approach into Gillespie here in the winter in a 172.. unforecast ice and given where he was on the LOC D no options other than to continue the approach.. by the time they broke out they were all full power and barely maintaining 65 knots..
Second story less scary, but one of the TKS panels on the wing never got soaked, so one portion of the wing has a solid chunk..
I was not in either plane so can't speak to the "this is the biggest fish I've caught" veracity
wanttaja
En-Route
Sorry, my data is primarily homebuilts. I found eight icing-related accidents in my 1998-2018 homebuilt accident database (out of ~4200 accidents).
I do have a 1998-2014 Bonanza 36 database. Also has eight cases of icing. Two of the cases, the NTSB states that the airplane was not approved for flight in known icing condition; in two others, it says the airplane was not equipped for icing conditions. No statement is made in the other four.
Accidents:
CHI98FA107
CHI00LA089
ATL03LA046
CHI03FA078
CHI03FA094
ATL07FA040
CEN09LA122
WPR14FA094
Was impressed by this one:
"....The pilot reported that once he had '...the runway made' he lowered the landing gear at which time the airplane began 'to sink and lose altitude rapidly despite my use of full power and attempts to level off.' The airplane impacted the rough terrain approximately 1/4 mile short of the approach end of the runway. Inspection of the airplane revealed it was covered with about 2 inches of ice. " (CHI00LA089)
Two INCHES of ice.
I have another database of Cessna 210 accidents from 1998 through 2014. Four icing accidents there. One aircraft was plumbed from the factory FOR boots, but they were apparently never installed. Another said the pilot handbook prohibited flight in icing conditons. No mention was made in a third case, but the fourth was equipped for known icing.
Accidents:
LAX02FA018
DEN00FA025
LAX05FA132
SEA05FA092
Another interesting bit of byplay:
"According to an FAA Flight Standards District Office (FSDO) inspector, the owner of New Mexico Flying Service appeared at the FSDO office in Albuquerque on March 3, 2000. In front of the secretaries, he tore up his air carrier operating certificate and left. " (DEN00FA025)
Also happen to have a Cirrus database running from 1998 through 2014. It has six cases of icing. One is listed as having used an icing protection system that was intended for accidental icing, not for flying into areas of known icing. Two others were listed as being prohibited from flying in known icing conditions. One had the Cirrus TKS, which is apparently approved for known ice. Another had TKS, but the pilot apparently activated it when he should have turned on pitot heat. Another case, the ice protection status of the airplane wasn't listed.
Accidents:
LAX05FA088
ATL06LA035
DEN06FA131
LAX07FA021
DEN07LA082
CEN14IA139
Ron Wanttaja
Tantalum
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Thanks, interesting stuff. As with most "how safe is flying" questions what's missing here is the data on all the planes that made it through icing events (FIKI or not), to get both sides of the sample. It does appear however, from a tertiary glance, that fewer planes with FIKI crash.. although the sample size here is admittedly small
I agree.. there is so much wrong with this!
I agree.. there is so much wrong with this!
He was in a non-FIKI TKS equipped SR22. It has been a while since I talked to him about the incident but what I remember of the story is that the weather was ok on departure but the ceilings became lower than expected, limiting airport/approach options and as he continued on somewhere he could land the tops became much higher than forecast. The TKS couldn’t keep up and it gave him one shot at getting into an airport. He ended up doing an approach at full power to maintain the glideslope and keep the airspeed up enough so the airplane didn’t stall.
It’s not a great story, but a good example of how someone can depart thinking they’re going to be safe and have options, only to have things go wrong and all the options you thought you had disappear.
Kristin
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No! But it might constitute "known icing conditions". We would need more information as to what the entire weather briefing indicated to make that determination. From the cited legal opinion:
"Pilots should also carefully evaluate all of the available meteorological information relevant
to a proposed flight, including applicable surface observations, temperatures aloft, terminal
and area forecasts, AIRMETs, SIGMETs, and pilot reports (PIREPs). As new technology
becomes available, pilots should incorporate the use of that technology into their decisionmaking
process. If the composite information indicates to a reasonable and prudent pilot
that he or she will be operating the aircraft under conditions that will cause ice to adhere to
the aircraft along the proposed route and altitude of flight, then known icing conditions
likely exist. If the pilot operates the aircraft in known icing conditions contrary to the
requirements of§ 91 . 9( a), the FAA may take enforcement action."
Read the opinion. "Known ice" is when it is sticking to the plane. What the limitations say in your POH comes into this.
midwestpa24
Final Approach
Living in the upper Midwest, I've heard lots of icing horror stories, but have managed to escape making any of my own. Granted I don't fly FIKI aircraft often. I have seen quite a few interesting examples show up on the ramp though. Often the pilots have the same pale, clammy appearance.
Kristin
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I have had a few icing adventures between flying night cargo out of MN and pax out of the UP and a stint at a commuter in SE Alaska. Some in FIKI certified planes and some in merely deiced airplanes. What is needed more than a "known ice" bird is a "known ice" pilot. It is all about limitations.
Tantalum
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Interesting.. glad he made it out of that one! I don't envy people who get in situations like that, but we can learn from others who do, and especially those that survive
For what it's worth, the FIKI approved TKS Cirri are much more capable than the non FIKI TKS ones, which, were basically designed to just hopefully keep you alive if you got into ice. The actual FIKI ones have larger panels, more protection, and additional backup pump. They did 100 hours of actual real world ice testing, plus wind tunnels, etc., in order to get pass certification. The max setting will provide 400% flow rate. Page 12 here has a good write up: https://www.steelaviation.com/wp-content/uploads/2018/10/Cirrus-Aircraft-The-History.pdf I wonder how his experience would have differed in FIKI
*I have found it sometimes takes 3-5 minutes for the panels to get wet too... that can feel like an eternity when you're watching ice build up out there.. good practice is to fire the thing on high for a few minutes prior to entering expected ice, and then hang out on norm. Personally, even if it's not forecast, if I see under 5*C and clouds ahead of me I turn it on. Very reassuring seeing a clean wing with the TKS streaming back while the windshield and wingtips are iced up (but also kinda scary!)
Not to say people should plow into icing conditions in really *any* plane.. from what I understand no plane really "hangs out" in the ice..
PS... there was one idiot who was unaware of the POH limitations of the plane and turned on FIKI at some absurd temp, like -45 OAT or something.. he posted it about it on COPA with pictures... as the TKS streamed back it appeared to freeze!
Morgan3820
En-Route
So then if there is a cloud layer at 3,000 with tops at 5,000 and the freezing level is 2,000, I can’t pubnch through to cruise at 6,000. Because then I would be going through icing conditions to get into the clear. Am I wrong?
Tantalum
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That's how I've always understood it and been tought, yes..
midwestpa24
Final Approach
Freezing temps and clouds don't always equal icing conditions. If there is no forecast for icing, and no PIREPs, it may still be ok to go. But you need to keep a Plan B in your pocket, and a Plan C. In your scenario, there is room under the cloud layer to descend, and warmer air below. So Plan B if you found ice in the layer would be to descend back to VMC conditions. Now if the ceiling was only 500 feet AGL, you can't do that safely.
MauleSkinner
Touchdown! Greaser!
The limitations in the POH/AFM probably use the term “known icing conditions”, not “known ice”.
There used to be an interpretation letter that said below-freezing temperatures in visible moisture constituted known-icing conditions, but the FAA rescinded that when the Bell letter came out in 2009. The newer letter says that "The FAA does not necessarily consider the mere presence of clouds (which may only contain ice crystals) or other forms of visible moisture at temperatures at or below freezing to be conducive to the formation of known ice or to constitute known icing conditions. There are many variables that influence whether ice will actually be detected or observed, or will form on and adhere to an aircraft." Later, the letter goes on to say "As new technology becomes available, pilots should incorporate the use of that technology into their decision-making process. If the composite information indicates to a reasonable and prudent pilot that he or she will be operating the aircraft under conditions that will cause ice to adhere to the aircraft along the proposed route and altitude of flight, then known icing conditions likely exist."
In other words, ice-forecasting technology is better than it used to be, and we should make use of it.
James331
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Kinda sorta
Kristin
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It depends on what is in your AFM/POH. If there is not a limitation for flight into icing conditions, then the only thing the FAA can bust you on is careless and reckless, 91.13. It would be a tough argument that punching through, especially on the way down, was careless or reckless, but you might have to spend money defending yourself. However, my experience with the Feds these days is that unless there is a clear paperwork violation, they aren't doing enforcement.
Kristin
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I haven't surveyed a lot of AFM's for this, but on aircraft produced after the 70's I would bet you are correct.
midwestpa24
Final Approach
As pointed out by Palmpilot, freezing temperatures and visible moisture alone don't necessarily present icing conditions.
Tantalum
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True.. but most people would be vigilant not to fly into said conditions without some type of ice equipment (outside of pitot and carb heat)
midwestpa24
Final Approach
True, but even as conservative as I am I have done it. Depends largely on what are the ceilings below, how thick the layer is, and better yet, PIREPs from other pilots as to what they have actually experienced. If it was always a hard no, GA would come to a standstill around here for months at a time.
MauleSkinner
Touchdown! Greaser!
But as pointed out by the legal interpretation, “known icing conditions” exist when a reasonable person would expect ice.
Rockymountain
Pre-takeoff checklist
Yes, some of the Cirrus fatal icing accidents as well as CAPS deployments were in TKS equipped aircraft. The most famous was the 2005 Norden CA accident where the TKS equipped Cirrus departed controlled flight in icing and by the time CAPS was deployed was beyond the structural speed for CAPS and the parachute ripped off. But several others. I don't know of any confirmed FIKI Cirri where ice was labeled as the cause of the loss of control, The most suspicious was the Newcomerstown FIKI Cirrus crash that claimed the life of a physician. While the NTSB looked at some erratic electrical system anomalies as the possible cause for the LOC, I believe Scott D did a weather analysis of that aircraft and felt like it was probably in significant icing when it lost control, and I still wonder if the apparent anomalies that occurred with the electric al system and bolster switches was in response to icing.
Tantalum
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FIKI Cirri <> TKS Cirri
The FIKI ones have a substantially more capable system with more panels, pumps, etc
But point taken, neither are infallible, and best not to hang out in ice
Zeldman
Touchdown! Greaser!
After landing I usually break off the ice and use it to cool off the cocktail I am drinking...
N1120A
Pattern Altitude
FIKI TKS works. Tantalum and I saw that first hand, but we also strapped on O2 and climbed out of it.
I'm not sure if any FIKI TKS planes have been wrecked due to icing, but certainly some non-FIKI TKS Cirrus' have.
A major boot accident was the Comair Brasilia that came down because their manuals and training required 1/2 inch of ice to form before blowing the boots, while Embraer had specifically said the system should he be activated as soon as icing was encountered. That plane actually had the ability to shed ice in bad conditions, unlike the ATR that went down in Indiana, but crap training and procedures did them in.
I'm not sure if any FIKI TKS planes have been wrecked due to icing, but certainly some non-FIKI TKS Cirrus' have.
A major boot accident was the Comair Brasilia that came down because their manuals and training required 1/2 inch of ice to form before blowing the boots, while Embraer had specifically said the system should he be activated as soon as icing was encountered. That plane actually had the ability to shed ice in bad conditions, unlike the ATR that went down in Indiana, but crap training and procedures did them in.
Rockymountain
Pre-takeoff checklist
The vast majority of icing accidents occur in non FIKI aircraft, but the majority of flight in icing conditions occurs in FIKI certified aircraft. Especially for new certifications, the systems are very robust. However, icing certification has become tougher, and many if not most legacy FIKI aircraft would not pass current certification standards without modification. But not-with-standing, you need to use all the tools, including weather knowledge, systems knowledge, and POH procedures when flying in ice, because any plane can be brought down by icing, by not doing the right things.
PaulS
Touchdown! Greaser!
FIKI Cirrus work really well in certified conditions. Part of being legal to use the Cirrus piston fiki system is to take the Cirrus course every 2 years, many Cirrus pilots seem not to know this and do things like full flaps on landing with ice on the airframe which is not allowed.
As far as not flying when ice is forecast, you would not fly around here if there are clouds in the winter if that were the case. I was up the other day, 3,900 foot ceilings, multiple ice reports in the clouds, below the clouds were fine. My plan was to stay below the clouds for a short cross country, which worked. I had FIKI tks if there was an issue if the ceilings lowered, they didn't, not that much anyway.
Tantalum
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It's a remarkable system when used correctly. I find that on "normal" ice no longer builds but it also doesn't really shed, the occasional switch to "high" sheds it right off without a problem.. have never had to use MAX in anger
The Cirrus learning management portal system is great, there's no reason to fall behind on any of the recurrent stuff
PaulS
Touchdown! Greaser!
I'm relatively new to using the system, been in actual about 8 times, 4 with an instructor and the other times on my own. The last time, about 5 weeks ago, was in Syracuse, punching through a pireped area of light to moderate rime. The layer was about 2,000 thick. As in most cases I had the system on normal before in the cloud. One time, on my long x country instrument, we were asked to climb through a layer that turned out had ice in it, we figured that out by seeing it on the wing. Normal took care of it.
Tantalum
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My CSIP was a little "braver" than me.. I've had about a dozen actual icing encounters, 4 where with the CSIP.. 3 were through layers, one was prolonged (about 45 minutes). Neither of us had our cannulas so we were altitude limited and skimmed along the tops. We always had an out (30 minute rule O2, yes we had oxymeters, or just descending, which would have been the obvious choice), and normal worked fine
But personally, when I'm alone, that sh#t freaks me out.. normal is the default for me but I see actual ice somewhere I just go to high to keep that wing CLEAN
Tantalum
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^and yes, misuse or incorrect use of the system can't be blamed on the aircraft, that's a pilot failure. Using flaps with ice, not wetting the wing out periodically so consequently the panels dry up, etc., are all issues with the pilot, and not the plane. Unlike boots, which actually have become overwhelmed and will fail to shed sufficient ice. I wonder how often the TKS equipped Cirri are wetted, some probably go years.. and then they wonder why it doesn't work in actual ice.
N1120A
Pattern Altitude
The TBM is supposed to be more robust in ice than a Cirrus. That didn't stop one from being brought down when it sat too long in bad ice.
There are older FIKI planes that are known for being particularly bad - the booted Caravans come to mind. Of course, there are non-FIKI planes that are known to carry ice very well - the Aztec and Navajo come to mind.
Still, unless you are in something with a very large, heated wing, you aren't supposed to sit in ice for long.