Practical Difference Between FIKI and Inadvertent Deice

[iamtheari]

This seems to be a rabbit hole that is easy to fall into and impossible to escape from. It seems to me that the current state of affairs is that a part 91 light airplane operator whose plane is not approved for flight into known icing conditions can legally fly into conditions that might lead to airframe icing as long as he has a good plan to get out of the icing if it happens and actually does get out of the icing when it happens and, if anything happens, the pilot will be judged after the fact based on his planning and in-flight decision making.

Meanwhile, the operator of a light plane that is FIKI approved can legally fly into known or probable icing conditions and keep going in those conditions, but common sense says he should really be working promptly to get out of the icing when it happens and, if anything happens, the pilot will be judged after the fact based on his planning and in-flight decision making, under the guise of recklessness. The FIKI systems usually have greater capabilities such as larger TKS tanks (Cirrus) or hot plates instead of windshield sprayers (Twin Cessnas). But no deice system on a light plane is unlimited.

In both cases, the pilot needs to understand the limitations of his deicing equipment so he can both survive encounters with icing and keep his pilot certificate. Basically, you always have to ask yourself:

1. Based on all information I can get, what are the chances I’ll pick up ice and how bad is that icing likely to be?
2. How will I get out of the icing if it occurs?

I actually ask myself those same questions flying my totally unprotected airplane. The answer to #2 is just a lot simpler: stay out of the clouds if they are likely to make airframe ice.

So, since the process of planning, avoiding, and getting out of icing is the same other than the duration and severity of icing you can stay alive in, what is the practical difference between a FIKI light plane and a similarly-equipped non-FIKI plane?

 

[Radar Contact]

what is the practical difference between a FIKI light plane and a similarly-equipped non-FIKI plane?

In my opinion, based on the only difference between my full de-ice and a FIKI Twin Cessna is hot-plate vs alcohol spray bars, it’s semantics.

If you are about to depart and the tower tells you a PIREP from the preceding departure of, “light mixed in the climb tops 1800 clear above”, you are now not legal to depart even though in my opinion it would be just as safe in my plane as a FIKI 310.

Same goes for arrival. If it’s told to you by the preceding arrival it’s hard to claim it’s not known at that point (regardless of safety). Of course you can decide about rolling the dice or not. My career won’t allow me to have that discretion.

 

[gsengle]

I believe FIKI is less about anti ice / deice capability and more to do with redundancy. For example, if your only power source becomes unavailable on a non fiki TKS installation, you have to exit icing because you’re losing the fluid pumps. On a fiki installation - say my M20R, there are two alternators two batteries and two pumps for the fluid... one failure doesn’t leave you with only an immediate exit as an out.


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[Kristin]

This seems to be a rabbit hole that is easy to fall into and impossible to escape from. It seems to me that the current state of affairs is that a part 91 light airplane operator whose plane is not approved for flight into known icing conditions can legally fly into conditions that might lead to airframe icing as long as he has a good plan to get out of the icing if it happens and actually does get out of the icing when it happens and, if anything happens, the pilot will be judged after the fact based on his planning and in-flight decision making.

Meanwhile, the operator of a light plane that is FIKI approved can legally fly into known or probable icing conditions and keep going in those conditions, but common sense says he should really be working promptly to get out of the icing when it happens and, if anything happens, the pilot will be judged after the fact based on his planning and in-flight decision making, under the guise of recklessness. The FIKI systems usually have greater capabilities such as larger TKS tanks (Cirrus) or hot plates instead of windshield sprayers (Twin Cessnas). But no deice system on a light plane is unlimited.

In both cases, the pilot needs to understand the limitations of his deicing equipment so he can both survive encounters with icing and keep his pilot certificate. Basically, you always have to ask yourself:

1. Based on all information I can get, what are the chances I’ll pick up ice and how bad is that icing likely to be?
2. How will I get out of the icing if it occurs?

I actually ask myself those same questions flying my totally unprotected airplane. The answer to #2 is just a lot simpler: stay out of the clouds if they are likely to make airframe ice.

So, since the process of planning, avoiding, and getting out of icing is the same other than the duration and severity of icing you can stay alive in, what is the practical difference between a FIKI light plane and a similarly-equipped non-FIKI plane?

The dichotomy which you pose as not real basis in the law, nor does it really line up with the way I think about icing, as a pilot who has been flying in icing conditions for 40 years.

Legally, there is no Part 91 prohibition against flying in the ice. There are two provisions that can play into it. One, 91.9 requires adherence any limitations in the AFM. The other provision is 91.13 to be used if icing causes you to crash. After some point in the 70's, the AFM's started to have limitations about flying in the ice. However, the limitations came out before FIKI certification became a deal. Much depends on when the aircraft was originally certified. If you look at an aircraft certified in the 50's and produced in the 60's, they are often entirely devoid of any limitation on flying in the ice. After the FAA started requiring AFM's, then you had aircraft, like a Piper Navajo, as an example, would state that the aircraft was approved for flight into equipped with the deicing options in fly into light to moderate ice, so some such. For the Navajo, Piper certified it FIKI, starting with the 1979 model. Then the wording changed a bit. Instead of saying "approved" there were words to the effect that flight into "known icing" was prohibited.

I have put ice on everything from a Tomahawk to a King Air. I have just never put too much on and only some of the time was intentional. The reality of flying in the north, there are many, many times where you need to punch through a layer 1,000 to 2,000 feet thick. Stratiform icing like this does not typically develop severe icing as that really takes some lifting action IMX. I don't think I have even put more than about a 1/4" of ice punching through layers like that. Keeping in mind, I do everything I can to limit the time in those layers unless fully equipped to deal with the ice.

I have always thought the the FAA has the icing focus in the wrong place. They focus on the plane. The focus, IMO, should be on the pilot. Training would go a long way, but no one teaches how to penetrate ice and everyone seems to think that will encourage flying into it. Like somehow ice is so rare up in the north that we can just pick and choose when we go. But no one parks the plane for 6-7 months so as to avoid all possibility of encountering ice.

 

[PaulS]

For the Cirrus aircraft there are many big differences between the inadvertent system and the FIKI system for the 22. 8 versus 4 gallons of tks fluid, more surfaces protected, extensive testing. This cirrus history by Steele aviation gives a pretty good overview of the differences between Cirrus generations. Check out pages 9 and 13 for the icing systems differences.

https://www.steelaviation.com/wp-content/uploads/2016/12/cirrus-history.pdf

 

[iamtheari]

Legally, there is no Part 91 prohibition against flying in the ice. There are two provisions that can play into it. One, 91.9 requires adherence any limitations in the AFM. The other provision is 91.13 to be used if icing causes you to crash. After some point in the 70's, the AFM's started to have limitations about flying in the ice. However, the limitations came out before FIKI certification became a deal. Much depends on when the aircraft was originally certified. If you look at an aircraft certified in the 50's and produced in the 60's, they are often entirely devoid of any limitation on flying in the ice. After the FAA started requiring AFM's, then you had aircraft, like a Piper Navajo, as an example, would state that the aircraft was approved for flight into equipped with the deicing options in fly into light to moderate ice, so some such. For the Navajo, Piper certified it FIKI, starting with the 1979 model. Then the wording changed a bit. Instead of saying "approved" there were words to the effect that flight into "known icing" was prohibited.

My 1968 Arrow is placarded "THIS AIRCRAFT IS APPROVED FOR NIGHT IFR NON ICING FLIGHT" and the same language appears in the POH. I am fairly confident that day and night VFR and day IFR are implicitly approved. I don't know what "non icing flight" means since I can't find a definition of that anywhere. Anyhow, that's just a data point for a 1968 airplane saying something specific about icing. This thread is not about trying to take the Arrow through a 5,000-foot layer of -5C clouds or anything like that.

Your post seems to support my initial thought, which is that, for a part 91 operation using piston-powered light airplanes, FIKI is a distinction without a difference. To be clear, I am not saying that a non-FIKI Cirrus is equally capable to a FIKI Cirrus, or anything like that. I just mean that every plane has a certain set of capabilities and, whether it is FIKI or not, it is up to the pilot to make intelligent preflight and in-flight decisions about whether the plane's capabilities are adequate for the conditions of the flight.

 

[Tantalum]

Yes, Paul and gsengle are right, at least in modern applications it's not just a difference in paperwork, there's massive system capability and redundancy differences and in the case of the Cirrus more coverage areas

 

[bobmrg]

"...and keep going in those conditions,..."

I do not believe that this is the case. FIKI just buys time to escape the icing conditions. Read up on icing in FAR 23 and FAR 25 (incorporated in Part 23 by reference) to see what "known icing" means in the certification process. These references specify the maximum time an airplane being considered for known icing certification can spend in stratus clouds or in cumulus clouds.

Bob Gardner

 

[gsengle]

"...and keep going in those conditions,..."

I do not believe that this is the case. FIKI just buys time to escape the icing conditions. Read up on icing in FAR 23 and FAR 25 (incorporated in Part 23 by reference) to see what "known icing" means in the certification process. These references specify the maximum time an airplane being considered for known icing certification can spend in stratus clouds or in cumulus clouds.

Bob Gardner

My Mooney can continue in known ice as long as you have fluid to do it... it does just fine. Ditto the Cessna 402 I flew, as long as the boots keep working etc. Fiki doesn’t mean you have to exit.


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[midlifeflyer]

So, since the process of planning, avoiding, and getting out of icing is the same other than the duration and severity of icing you can stay alive in, what is the practical difference between a FIKI light plane and a similarly-equipped non-FIKI plane?

The answer is in part the certification of your anti-ice equipment and your own personal minimums. "Stay in" or "get out."

Assuming we're talking "get out," the primary difference I see is urgency. That translates to me as two practical differences. One is at the planning stage. Using aviaionweather.gov's FIP tool in combination with cloud layer/freezing level forecasts, I might be willing to accept a greater icing probability/severity over a wider area at my planned altitude with FIKI than without. The second is in that encounter. In either case, I am asking ATC for what I need to get out. But with FIKI I can be more casual about it because the system buys me some time; without, I am going to let ATC know my needs are urgent.

 

[Kristin]

My 1968 Arrow is placarded "THIS AIRCRAFT IS APPROVED FOR NIGHT IFR NON ICING FLIGHT" and the same language appears in the POH. I am fairly confident that day and night VFR and day IFR are implicitly approved. I don't know what "non icing flight" means since I can't find a definition of that anywhere. Anyhow, that's just a data point for a 1968 airplane saying something specific about icing. This thread is not about trying to take the Arrow through a 5,000-foot layer of -5C clouds or anything like that.

Your post seems to support my initial thought, which is that, for a part 91 operation using piston-powered light airplanes, FIKI is a distinction without a difference. To be clear, I am not saying that a non-FIKI Cirrus is equally capable to a FIKI Cirrus, or anything like that. I just mean that every plane has a certain set of capabilities and, whether it is FIKI or not, it is up to the pilot to make intelligent preflight and in-flight decisions about whether the plane's capabilities are adequate for the conditions of the flight.

We pretty much agree! An aircraft being "approved" for something and by implication "not approved" for other operations is different than an aircraft that is "prohibited" from those other operations. It seems a fine distinction, but the FAA knows how to use more definitive language when it wants to prohibit something. Here is an example from the AFM for a Chieftain after FIKI certification:
"Flight through any icing conditions is prohibited if any of the anti-icing or deicing equipment is missing or not functioning."

Or from the Twin Cessna icing AD 2014-03-03 requiring a placard stating: “This airplane is prohibited from flight into known icing conditions.”

My take on it is that the FAA doesn't now want to impose an outright ban on flight into known icing conditions, unless FIKI approved, in Part 91 as they know that it would have huge economic and political consequences. Further, it ignores the fact that there are non-FIKI birds, like all the Aztecs, which handle ice better than a lot of FIKI birds, but Piper never chose to certify them. So the FAA is playing the game of trying to talk pilots out of flying in the ice without banning it outright as the fact is that the professionals can do it safely without the FIKI system and a lot of hobby flyers are dangerous, even with a FIKI plane strapped on.

 

[Kristin]

Yes, Paul and gsengle are right, at least in modern applications it's not just a difference in paperwork, there's massive system capability and redundancy differences and in the case of the Cirrus more coverage areas

That may be true of Cirrus's, but not true for all other aircraft. I have flown FIKI and pre-FIKI Navajos. FIKI certification did little to improve safety. The plane got inboard boots between the nacelle and fuselage, which was a plane that ice didn't really build up anyway. It get a heated stall warning sensor. A stall warning vane is of little help in the ice at any rate. Then with the extra boots, they split the system so that the wing boots and the tail boots were blown at different times instead of blowing wings and tail together. Big deal! None of what makes a FIKI Navajo FIKI, actually improves the aircraft's ability to fly in the ice, IMX.

 

[Kristin]

My Mooney can continue in known ice as long as you have fluid to do it... it does just fine. Ditto the Cessna 402 I flew, as long as the boots keep working etc. Fiki doesn’t mean you have to exit.


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The only problem with the 402 is the required placard that says: “This airplane is prohibited from flight into known icing conditions.” Unless it is FIKI certified.

 

[MauleSkinner]

My take on it is that the FAA doesn't now want to impose an outright ban on flight into known icing conditions, unless FIKI approved, in Part 91 as they know that it would have huge economic and political consequences. Further, it ignores the fact that there are non-FIKI birds, like all the Aztecs, which handle ice better than a lot of FIKI birds, but Piper never chose to certify them. So the FAA is playing the game of trying to talk pilots out of flying in the ice without banning it outright as the fact is that the professionals can do it safely without the FIKI system and a lot of hobby flyers are dangerous, even with a FIKI plane strapped on.

I think it’s more a case of the FAA knows you can’t retroactively change certification rules...changes in certification rules (CAR3 & 4, FAR 23 & 25, for example) don’t change the certification requirements of an airplane certified under a previous version of those regs.

DC-3s or C-46s, for example, were certified well before “known icing” certification existed, and are therefore grandfathered into other authorizations for flight in icing if properly equipped.

 

[Tantalum]

That may be true of Cirrus's, but not true for all other aircraft. I have flown FIKI and pre-FIKI Navajos. FIKI certification did little to improve safety. The plane got inboard boots between the nacelle and fuselage, which was a plane that ice didn't really build up anyway. It get a heated stall warning sensor. A stall warning vane is of little help in the ice at any rate. Then with the extra boots, they split the system so that the wing boots and the tail boots were blown at different times instead of blowing wings and tail together. Big deal! None of what makes a FIKI Navajo FIKI, actually improves the aircraft's ability to fly in the ice, IMX.

I've read some sobering things with the older FIKI systems.. seems they were really just there for HOLY CRAP situations, with the FIKI paperwork done to help operators not be illegal

I am not aware of any single FIKI Cirrus crashing due to ice.. there are however one or two that went down, that were TKS equipped (but not FIKI).. however I'm not sure how those systems were used

The other thing with these systems is improper use. Boots typically need some accumulation, and the TKS really needs to run for a good 3-5 minutes prior to entering ice, the POH state to run it prior to entering expected ice. Or, if you turn it on already in ice (inadvertent), throw that crap on max.. and, this is assuming it gets wetted out from time to time. There are posts on COPA of people wondering if their system is broke because the minute the switch is on the wing isn't weeping. Takes that goo some time to work its way through the channels and the membranes

 

[Tantalum]

DC-3s or C-46s

What did these prop giants do with ice? I read somewhere that the DC6 (?) use a gas heater to blow hot air through the wings, that true?

 

[Kristin]

I think it’s more a case of the FAA knows you can’t retroactively change certification rules...changes in certification rules (CAR3 & 4, FAR 23 & 25, for example) don’t change the certification requirements of an airplane certified under a previous version of those regs.

DC-3s or C-46s, for example, were certified well before “known icing” certification existed, and are therefore grandfathered into other authorizations for flight in icing if properly equipped.

I think we are saying the same thing. Though the FAA can change the operational envelope by AD, as they did with the deiced, but non-FIKI twin Cessnas. Having flown a deiced but non-FIKI 310 in the ice on night freight runs, I am well aware of the limitations. The FIKI system in the twin Cessnas really was an upgrade. In Navajos, not so much. Changing Part 91 would be taking a meat ax to the issue and as you point out, would make a lot of sense as we have aircraft like the DC-3, Aztec, etc, that have proven themselves in the ice over decades. It is instructive to realize that even Part 135 does not require that a FIKI airplane be used.

 

[MauleSkinner]

What did these prop giants do with ice? I read somewhere that the DC6 (?) use a gas heater to blow hot air through the wings, that true?

DC-3s and C-46s had boots and alcohol, from what I understand. Don’t know about the DC-6s, but I’m pretty sure the Convairs had some kind of hot (or warm) air system for the wings.

 

[Kristin]

I've read some sobering things with the older FIKI systems.. seems they were really just there for HOLY CRAP situations, with the FIKI paperwork done to help operators not be illegal

Don't confuse "older FIKI systems" with pre-FIKI systems. The FIKI certification as been amended so there is early FIKI, later, FIKI, and pre-FIKI. For Cirruses, there is only FIKI and non-FIKI. Some of the non-FIKI has some deicing equipment, but not the same deal as pre-FIKI aircraft.

 

[MauleSkinner]

I think we are saying the same thing. Though the FAA can change the operational envelope by AD, as they did with the deiced, but non-FIKI twin Cessnas. Having flown a deiced but non-FIKI 310 in the ice on night freight runs, I am well aware of the limitations. The FIKI system in the twin Cessnas really was an upgrade. In Navajos, not so much. Changing Part 91 would be taking a meat ax to the issue and as you point out, would make a lot of sense as we have aircraft like the DC-3, Aztec, etc, that have proven themselves in the ice over decades. It is instructive to realize that even Part 135 does not require that a FIKI airplane be used.

Probably saying much the same thing.

for reference, here’s the Part 135 requirement for flight in icing conditions...

(c) No pilot may fly under IFR into known or forecast light or moderate icing conditions or under VFR into known light or moderate icing conditions, unless—

(1) The aircraft has functioning deicing or anti-icing equipment protecting each rotor blade, propeller, windshield, wing, stabilizing or control surface, and each airspeed, altimeter, rate of climb, or flight attitude instrument system;

(2) The airplane has ice protection provisions that meet section 34 of appendix A of this part; or

(3) The airplane meets transport category airplane type certification provisions, including the requirements for certification for flight in icing conditions.

Section 34 of Appendix A reads:

34. Ice protection. If certification with ice protection provisions is desired, compliance with the following must be shown:

(a) The recommended procedures for the use of the ice protection equipment must be set forth in the Airplane Flight Manual.

(b) An analysis must be performed to establish, on the basis of the airplane's operational needs, the adequacy of the ice protection system for the various components of the airplane. In addition, tests of the ice protection system must be conducted to demonstrate that the airplane is capable of operating safely in continuous maximum and intermittent maximum icing conditions as described in appendix C of part 25 of this chapter.

(c) Compliance with all or portions of this section may be accomplished by reference, where applicable because of similarity of the designs, to analysis and tests performed by the applicant for a type certificated model.

 

[Tantalum]

Don't confuse "older FIKI systems" with pre-FIKI systems. The FIKI certification as been amended so there is early FIKI, later, FIKI, and pre-FIKI. For Cirruses, there is only FIKI and non-FIKI. Some of the non-FIKI has some deicing equipment, but not the same deal as pre-FIKI aircraft.

Good point. I know in the case of Cirrus outside of both using TKS the systems are loads different when comparing FIKI to non

Was there no real icing certification standard in the 1960s then? What guidance did Boeing and commercial just makers have around ice protection if there was no legal benchmark?

 

[Plano Pilot]

What did these prop giants do with ice? I read somewhere that the DC6 (?) use a gas heater to blow hot air through the wings, that true?

True on the DC-6. My dad worked, as a mechanic, for Braniff in the mid 50's and said they were no fun to change.

 

[Kristin]

Good point. I know in the case of Cirrus outside of both using TKS the systems are loads different when comparing FIKI to non

Was there no real icing certification standard in the 1960s then? What guidance did Boeing and commercial just makers have around ice protection if there was no legal benchmark?

There only standard was that the manufacturer had to show that the deice equipment installed didn't screw up the airplane. That was it. Practicality and economics guided the design of transport aircraft as the airlines needed to keep schedules so demanded icing protection. I am not sure when the first Part 25 standards were implemented, but for Part 23 aircraft is was about 1975.

 

[Radar Contact]

Having flown a deiced but non-FIKI 310 in the ice on night freight runs, I am well aware of the limitations. The FIKI system in the twin Cessnas really was an upgrade.

Curious (value your opinion) why you think it was an upgrade. The only difference between my de-ice and a FIKI one is the inboard boots (little impact as you mentioned earlier) and hot plate vs alcohol windshield. Seems the spray bars clear more than the hot plate?

 

[Kritchlow]

In my opinion, based on the only difference between my full de-ice and a FIKI Twin Cessna is hot-plate vs alcohol spray bars, it’s semantics.

If you are about to depart and the tower tells you a PIREP from the preceding departure of, “light mixed in the climb tops 1800 clear above”, you are now not legal to depart even though in my opinion it would be just as safe in my plane as a FIKI 310.

Same goes for arrival. If it’s told to you by the preceding arrival it’s hard to claim it’s not known at that point (regardless of safety). Of course you can decide about rolling the dice or not. My career won’t allow me to have that discretion.

I flew a few different models of the 310 back in the day, and some models did not have boots on the inner portion of the wings between fuselage and engine cowl.
Not really sure if that is relevant to your discussion..??

 

[Kristin]

Curious (value your opinion) why you think it was an upgrade. The only difference between my de-ice and a FIKI one is the inboard boots (little impact as you mentioned earlier) and hot plate vs alcohol windshield. Seems the spray bars clear more than the hot plate?

I was flying pre-FIKI 310R models. They did not have boots on the vertical stabilator. They also didn't have inboard boots. Given the 310 had a somewhat thinner wing and those vent openings, it did build ice between the wing and the nacelle. The alcohol windshield is great until you have to turn it off to have it clear for landing and the windshield ices again. One of the hazards of low approaches in snow and icing.

 

[Radar Contact]

I flew a few different models of the 310 back in the day, and some models did not have boots on the inner portion of the wings between fuselage and engine cowl.
Not really sure if that is relevant to your discussion..??

That was basically what I was referring to. I avoid ice and use GA de-ice/anti-ice as an escape method vs marching on and I just fly for fun so I don't have a ton of ice experience in these planes. I've been told that the inner boots don't really do much. It was interesting to hear Kristin say that in her experience ice does develop there more than other twins due to the shape.

 

[Rockymountain]

One thing to add is that every few years the FIKI standards have been increased, and very few legacy aircraft would pass the current FIKI standards. More than just protecting the airframe, there has to be extensive testing with both working and failed systems, planes need to be tested and or mitigated for tail stall, SLD has to be addressed as do operating v-speeds. Do you know your approach and Vref speeds in ice, flaps failed or up, 1/2 flaps, landing flaps, limitations? Where are the points of failure and what is the redundancy? What are the safety alarms, in other words does it let you know if a TKS panel or boot is failed? Does it have a heated AOA indicator that compensates for ie contamination? Ice can be terrifying, and can take an unprotected or poorly protected plane down in short order. Some of the worst SLD icing can occur in relatively thin stratiform cloud layers, particularly after frontal passage in clean air over snow pack or lake effect areas. The CIP and FIP are probably the single best tool to determine likelihood and severity of icing if you had to hang your hat, but is also not perfect.

 

[Kristin]

It sounds from your description that pretty soon light FIKI aircraft will be priced out of the market plane entirely. If those are becoming the standards for light aircraft FIKI certification, I believe it strengthens my point that we need FIKI pilots more than FIKI planes. No matter how much of a book that they write about how to land a plane in a given configuration, they can't cover it all as no two icing events are exactly the same. Landing a contaminated airplane is not that hard if you know what you are doing. If the plane is flying, keep it flying until you are over the runway. Don't change anything unless you are certain you can do so safely and absolutely need to do so. If the airplane will fly at 120 KIAS without stalling, for example, fly it to the runway at 120 KIAS until you get into ground effect and reduce the power until it lands. If it will fly slower, slow it a bit, but fly it to the runway in whatever configuration is working for you. With a contaminated airplane to land, you are a test pilot. Fly it like a test pilot, but whatever, continue to fly it. Having V speeds determined by engineers who have probably never flown in the ice is worthless unless the recommended speeds were developed with the exact configuration, including shape, roughness, and location, of ice that is currently hanging on to the lifting surfaces.

I have yet to find SLD in a thin stratus layer. Maybe I have been lucky in my years of flying over the Great Lakes and in SE Alaska. Maybe it has always been there, but I just haven't felt the need to sit in that layer long enough to find out. That is the good thing about layers, generally, one can go through them fairly quickly.

The need to have warning systems on a light airplane to tell you whether a boot is not working seems to assume that the pilot is unable to look outside and see. I would submit if the FAA is trying to make the plane so blind pilots can fly in the ice, we have lots of other problems.

 

[Rockymountain]

I hear you. It is not making flying cheaper. But there are plenty of good weather days to fly light planes. If you want to fly on bad weather days, I think it is prudent to understand the limitations of the equipment, and understand why the FAA has a strong stand against flight in known ice and aircraft are required to be certified. Flying in ice in a non-FIKI aircraft is a little like playing Russian roulette, albeit there may be a lot empty chambers. Somewhere in there is a bullet. Just like that C182 that went down a couple of weeks ago. Sounds like there was an experienced commercial pilot at the controls. Probably not the first time he had flown in ice. Probably said, oh these 182's can handle a little ice, I can always descend or divert, or....... From the time he asked to descend for ice, descend again, then divert, until he was in a smoking hole in the ground with his passengers was less than 20 minutes. Flying in ice is stressful enough in a FIKI aircraft with robust systems, formal training, and POH guidance for operations. Doing that in a non-FIKI aircraft is just not wise and the NTSB reports are littered with the bodies of junior test pilots and their passengers. Just don't do it ;-) It is not OK. It is not safe. It is not wise.

As far as thin stratus layers not holding much ice. This accumulation was in a 1500 ft stratus layer, just a few minutes descending at 700 fpm on the ILS in a Piper Mirage. Some of it had melted as the ground was slightly above freezing, but that is about 3/8-1/2 inch accumulation. Which calculates to an inch about every 4-6 minutes, and is rough ice. That is juicy, and could take down an unprotected plane pretty quickly ;-)

 

[Kristin]

I think people are too focused on FIKI. Because such a certification exists, it temps people into thinking you are good if you have FIKI and are going to die if you don't have a FIKI plane. That kind of thinking is dangerous. So much depends on the conditions and the capabilities of the aircraft. Cherokees will handle a 1/2" of ice if you land hot. Of course, if you are going up through it, it will probably sublimate off. I don't recommend it, particularly when the temps are conducive to clear ice. But I have gone through many many layers knowing I would get ice, but knowing that it would be <1/4" of rime which would just be on the leading edge.

I can't tell from your picture whether that was SLD or not, but it appears to be clear ice. Where did this occur and what time of year?

I didn't read about the C-182, but sitting in ice for 20m is nuts even in a FIKI bird. All that equipment just buys you a bit more time to get out of it, not as a license to sit in it. I also get out as soon as possible not withstanding the capabilities of the airframe. That, IMO, is the key to not killing yourself.

 

[MauleSkinner]

Many, if not most, FIKI pilots I’ve worked with over the years are grossly under-informed with regard to where FIKI protection ends, and what the consequences of going past that point are...things like minimum speed for flight in icing, and how does that tie in with other procedures, like engine-out operations in multi engine aircraft.

 

[N1120A]

"...and keep going in those conditions,..."

I do not believe that this is the case. FIKI just buys time to escape the icing conditions. Read up on icing in FAR 23 and FAR 25 (incorporated in Part 23 by reference) to see what "known icing" means in the certification process. These references specify the maximum time an airplane being considered for known icing certification can spend in stratus clouds or in cumulus clouds.

Bob Gardner

My Mooney can continue in known ice as long as you have fluid to do it... it does just fine. Ditto the Cessna 402 I flew, as long as the boots keep working etc. Fiki doesn’t mean you have to exit.


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You're both right. If you encounter ice, you should try and find a way out. If you have a FIKI deice system, you can fly in the ice for a while till you find that out.

That may be true of Cirrus's, but not true for all other aircraft. I have flown FIKI and pre-FIKI Navajos. FIKI certification did little to improve safety. The plane got inboard boots between the nacelle and fuselage, which was a plane that ice didn't really build up anyway. It get a heated stall warning sensor. A stall warning vane is of little help in the ice at any rate. Then with the extra boots, they split the system so that the wing boots and the tail boots were blown at different times instead of blowing wings and tail together. Big deal! None of what makes a FIKI Navajo FIKI, actually improves the aircraft's ability to fly in the ice, IMX.

Navajos are completely different airplanes. Piper twins have always been built to carry ice, even when not FIKI. There is not a single FIKI Aztec out there, but they are legendary for carrying ice. As you said, there isn't a big difference in de ice and FIKI Navajos. That isn't the case of many other airplanes.

I've read some sobering things with the older FIKI systems.. seems they were really just there for HOLY CRAP situations, with the FIKI paperwork done to help operators not be illegal

I am not aware of any single FIKI Cirrus crashing due to ice.. there are however one or two that went down, that were TKS equipped (but not FIKI).. however I'm not sure how those systems were used

The other thing with these systems is improper use. Boots typically need some accumulation, and the TKS really needs to run for a good 3-5 minutes prior to entering ice, the POH state to run it prior to entering expected ice. Or, if you turn it on already in ice (inadvertent), throw that crap on max.. and, this is assuming it gets wetted out from time to time. There are posts on COPA of people wondering if their system is broke because the minute the switch is on the wing isn't weeping. Takes that goo some time to work its way through the channels and the membranes

Boots DO NOT need accumulation. Ice bridging is largely a myth, and the wive's tale about accumulation brought down a Brasilia and killed everyone on it. Plus, what worked on fat winged DC-3s is not what works on a modern plane with a wing optimized for efficiency. Just like "over square" is a left over from the days of radial engines.

Good point. I know in the case of Cirrus outside of both using TKS the systems are loads different when comparing FIKI to non

Was there no real icing certification standard in the 1960s then? What guidance did Boeing and commercial just makers have around ice protection if there was no legal benchmark?

They built planes with fat wings that could carry ice, in addition to putting boots or TKS on them.

Many, if not most, FIKI pilots I’ve worked with over the years are grossly under-informed with regard to where FIKI protection ends, and what the consequences of going past that point are...things like minimum speed for flight in icing, and how does that tie in with other procedures, like engine-out operations in multi engine aircraft.

This is very true.

 

[Tantalum]

Boots DO NOT need accumulation. Ice bridging is largely a myth, and the wive's tale about accumulation brought down a Brasilia and killed everyone on it. Plus, what worked on fat winged DC-3s is not what works on a modern plane with a wing optimized for efficiency. Just like "over square" is a left over from the days of radial engines.

...up there with shock cooling? lol =P

I can't find it now but there was a video on either LiveLeak or YouTube once showing a plane with the boots inflating and deflating and a small layer of ice just inflating along with it but not breaking off..

 

[Rockymountain]

Ice left over between boot cycles is called intercyle ice and is usually of little consequence as long as you obey the POH. Taking airframe ice to landing will usually require modified approach and over the number speeds and may also limit flap deployment.

 

[iamtheari]

Navajos are completely different airplanes. Piper twins have always been built to carry ice, even when not FIKI. There is not a single FIKI Aztec out there, but they are legendary for carrying ice. As you said, there isn't a big difference in de ice and FIKI Navajos. That isn't the case of many other airplanes.

FWIW, I have seen Aztecs for sale claiming FIKI certification. I think it was an option on the F models, but probably not any of the earlier models. And it is definitely not common in planes that are for sale, which either means it was a rare option or nobody will part with them.

 

[Kristin]

Navajos are completely different airplanes. Piper twins have always been built to carry ice, even when not FIKI. There is not a single FIKI Aztec out there, but they are legendary for carrying ice. As you said, there isn't a big difference in de ice and FIKI Navajos. That isn't the case of many other airplanes.

Of course they are. I never suggested otherwise. I merely gave an example in opposition to broad statements that were being made to the effect that only FIKI aircraft can safely or legally fly in the ice.

Boots DO NOT need accumulation. Ice bridging is largely a myth, and the wive's tale about accumulation brought down a Brasilia and killed everyone on it. Plus, what worked on fat winged DC-3s is not what works on a modern plane with a wing optimized for efficiency. Just like "over square" is a left over from the days of radial engines.

Ice bridging my be a myth, but I have yet to find anyone with significant ice flying experience who doesn't know that the ice generally sheds better if allowed to built up a bit before popping the boots.

 

[Kristin]

FWIW, I have seen Aztecs for sale claiming FIKI certification. I think it was an option on the F models, but probably not any of the earlier models. And it is definitely not common in planes that are for sale, which either means it was a rare option or nobody will part with them.

Lots of people think that anything with boots is FIKI. Most pilots don't understand the distinctions or legalities, let alone how to actually fly in the ice. Aztecs were "approved" to fly in the ice with the equipment, but never prohibited from flying in the ice without such. They were never certified for Flight into Known Icing.

 

[MauleSkinner]

Ice bridging my be a myth, but I have yet to find anyone with significant ice flying experience who doesn't know that the ice generally sheds better if allowed to built up a bit before popping the boots.

Ice bridging is only a myth to those who haven’t seen it.

 

[Kristin]

Ice bridging is only a myth to those who haven’t seen it.

Depends on what is meant by "ice bridging". The way NASA used it was has essentially as a leading edge cuff where the boot was inflating uselessly inside the ice cuff. That may or may not be a myth but I don't know anyone who has seen it like that. I have had ice that has adhered to the boots, in between the channels, which the boots were not removing.