Twin Performance Question

[Charles Schefer]

I am not intending to hijack this thread but I recall the original post did involve icing...

Thanks Kristin I've learned some things...

I just did some more research on this after reading Kristin's reply and it seems that while the 135 regs that I am used to are pretty clear on the issue it's a bit more murky under Part 91. We could have a separate discussion on what is "safe" or "smart" but here I am looking specifically at what is "legal".

In doing some quick research I came across the following interesting reads. I won't regurgitate all the articles say but they are worth a read. I'll give a few highlights below...

https://www.faasafety.gov/gslac/ALC/cou ... eview=true
http://www.aerolegalservices.com/Articl ... 2-25.shtml
http://www.aopa.org/News-and-Video/All- ... definition

As I surmised earlier the FIKI / non-FIKI classification of icing systems really comes down to the certification process (and standards/regs) the manufacturer when thru (or not) during certification of the aircraft with that system.

Part 91 it's murky. There is no specific icing reference in Part 91 other than 91.527 which does not apply to our smaller aircraft. AIM 7-1-22 does discuss "known icing".

91.9(a) states that a pilot must comply with the operating limitations of the aircraft per the manufacturer (Section 2 of the AFM/POH - Limitations).

- In the case of my Cirrus aircraft the limitations section does in fact state "Flight Into Known Icing Prohibited". Newer Cirrus with the FIKI certified system do not have this limitation.

- The original AFM (circa 1968) for my PA-30 has no such limitation I can find in the Limitations Section.

- The ICS (Killough) AFM for the PA-30 states on Page 2-5 "Flight into known icing conditions is prohibited unless the following equipment is installed and working in accordance with applicable Piper drawings and FAA regulations..." It then goes on to list the STC equipment for what I assume is the Wiggins system.

More on the Limitations Section the above at the end of this post...

91.13(a) prohibits careless or reckless operation. Whether intentionally launching into FIKI conditions in a non-FIKI aircraft is considered "careless or reckless" is subject to interpretation.

FAR 91.103 specifies that "each pilot in command shall, before beginning a night become familiar with all available information concerning that flight: including weather reports and forecasts for flights under IFR or not in the vicinity of the airport."

It seems there is legal case history to show that the FAA and NTSB have used the regs above in certification action against pilots (Part 91) when icing was a causal factor in an incident or accident. That said it's clearly open for debate and interpretation. One of the legal references above concludes:

"At the end of the day, this Legal Interpretation does not give pilots a "bright-line" test to use in answering the "known icing conditions" question. However, it makes clear that pilots will still need to evaluate all available information both before and during a flight in order to make a reasonable determination as to whether "known icing conditions" are present along the proposed route of flight. Pilots will also need to be able to prove that they performed this evaluation if they find themselves defending against an alleged violation arising from an icing situation."

Going back to 91.9(a) and the AFM Limitations section. From a purely legal standpoint (irrespective of what is smart) I suppose if you want to launch a Wiggins equipped PA-30 into known icing it is not illegal based on the statement in the ICS AFM/POH on page 2-5. However if you have a non-Wiggins equipped PA-30/39 (or PA-24) as most of us do, AND you are using the ICS AFM - then yes it is illegal to launch based on the limitation on Page 2-5 and FAR 91.9(a). I suppose you could get around the limitation by reverting back to the original Piper AFM/POH from the 1950s-1960s which appears to remain silent on the issue.

This is my read....

- Charles

[Kristin Winter]

Charles,

That is basically my understanding as well. There is a lot of confusion about this in the general population of GA pilots. There is no prohibition about launching your non-deiced Comanche, or any other CAR 3 certified aircraft into icing conditions, known or otherwise. "Known Icing" is purely a certification. You are correct that if you load up with ice and crash, you are likely to run into an enforcement action based on 91.13, but in absence of crashing, the FAA would have a very hard case to make.

It is helpful to consider that there are two bases for the certification of deicing/anti-icing equipment on aircraft. Prior to a revision to Part 23 in the 70's, or there abouts, all the manufacturer had to do to put icing equipment on the plane was to show that it wouldn't harm the flight characteristics. This can be thought of as "no harm" systems. They did not have to show that they worked to actually protect against icing. At a certain point, the manufacturers had to show that the systems would actually allow the airplane to fly safely in certain icing conditions. This new section was titled "Flight into Known Icing Conditions" i.e. FIKI. With aircraft certified after FIKI came into effect, either had the equipment which had been proved, or they got the limitation in the AFM. It is indeed illegal to fly most Part 23 certified aircraft into known icing conditions when the prohibition is in the AFM.

One of the things that confuse folks, and confused me until the FAA forced me to do the research when an ASI went off the deep end and tried to ground our fleet Aztec, is the aircraft that have the deicing equipment but are CAR 3 aircraft. Our 1974 Aztec's AFM did not state a limitation, rather it said that the aircraft could handle light to moderate icing conditions if the following equipment was installed, and then it listed the entire deice package. The ASI said I couldn't operate that aircraft 135 unless it was FIKI approved. He was wrong as AC 135-9 pointed out and I even confirmed it with top FAA folks in Washington. The 135 regs at that time, which may have changed, only state that you have to have deicing equipment covering each wing, tail, etc, but said nothing about FIKI certification. Our 1976 Navajos were also not FIKI, but the ASI didn't seem to know that as he didn't raise that issue. However, both carry ice better than some FIKI certified aircraft, so it would be hard to argue careless or reckless with these aircraft.

So yes, you can fly your 180 Comanche into known ice. I have put ice on most all light aircraft I have flown, as that is sort of what happens when you fly up north. Mostly it has never been more than a trace on the leading edge, but I knew that I was going to get the ice when descending through that 1000 foot layer while being vectored for the approach. It is a fact of life half of the year up north. I think that is one reason that the FAA has not promulgated a Part 91 ban on flight into known icing conditions until so certified as it could shut down most GA in the U.S. for half the year.

[Charles Schefer]

Thanks Kristin, I learned something looking into this. My frame of reference was a newer certified aircraft (Cirrus) with a non-FIKI TKS system and the prohibition in the Limitations section so it seemed pretty clear to me in that regard. I think that with newer aircraft it is more clear as you highlight. Until this thread it never dawned on me that due to the absence of the limitation in older AFMs for older aircraft it is therefore legal (or not "illegal").

For the reasons stated in my earlier post I'd still say there is room to argue either way in the gray areas and you can be the FAA would leverage that gray area to support their argument in an enforcement action.

I think it's also clearly true that any PA-30 / 39 / 24 using the newer ICS AFM does have the limitation in the AFM unless the aircraft has the Wiggins system (I am assuming the PA-24 AFM is similar to the PA-30 AFM I have). Therefore due to FAR 91.9(a) and the limitation on page 2-5 of the ICS AFM - that does make it illegal. If you want to launch into known ice in your Comanche you have ditch the ICS AFM and claim the original AFM as your aircraft's "current" flight manual.

- Charles

[Charles Schefer]

[GMTW]

Wiggins had more than one boot system, one is activated by a nitrogen bootle in the luggage compartment and one that came out in the late 60's that is pump activated. The POH says that "flight into known icing not approved unless equipped with two wiggins stc's which are the pump boots and the alcohol props and the hot plate installed iaw the piper drawing."
I have a pa39 that is equipped this way so if I'm challenged I'll argue. That being said I continue to avoid ice like the plague but have been thankful to have the equipment. The system seems to boot ice well.

I also have turbo's on the aircraft and like them. I fly where mea's are as high as 16000 ft and the turbos make the aircraft. It's true the aircraft is a little slower below 8000 ft but above that it comes alive.

John

[Kristin Winter]

Charles,

I agree that most folks that are using the Killough manual as the AFM have a limitation. However, I bet that 99%+ of those using the manual, have never made it official with a 337 or even a logbook entry. Since the Killough manual is approved, it would seem that it need be officially adopted through some paperwork. My gut feeling is that it is a major alteration so needs a 337. Of course, most who are using the Killough manual probably don't have the original Piper mimeographed sheets which constitute the AFM, so defending a 91.9 bust by saying that the Killough manual is not the AFM would leave most open to an enforcement action for not having an AFM with the limitations. I keep the Killough manual in my plane, but it has market as for information only and not the AFM.

Interestingly, Supplement #1 to Piper report 1515 which is what applies to my C model Twinkie addresses the issue by stating: "The following items of equipment must be installed and operable to effectively cope with normally encountered icing conditions:" It then goes on to list the Wiggins equipment. Needless to say, this is informational and not regulatory.

I believe that starting around 1976, the FAA has been coercing the manufacturers to add a limitation to the AFM, even ones that were certified under CAR 3. The Aztec AFM was changed to require its deicing package -- non-FIKI though it is -- to fly into icing conditions. Though it is in the limitations section, the wording is rather ambiguous so I could likely mount a decent defense to an enforcement action based on 91.9. Killough came right out and said it was prohibited and the FAA bought off on it as an STC, so I do think that if you are using that for an AFM you are stuck. I would recommend that everyone with a Comanche make sure that they have the original as they official AFM and just use Killough for planning purposes.

A Cirrus without TKS is very scary in the ice. I would even take an equipped, non-FIKI Aztec over a FIKI Cirrus. Without the TKS, the Cirrus apparently has little intrinsic ability to handle ice. Even without deicing equipment, I think it would take a lot of ice to bring down an Aztec.

[Kristin Winter]

[GMTW]

Kristin;

I'm quoting kellog but i think the piper is similar; I'll go back to the airport tomorrow and check. I had piper send me a copy of the original so I had a starting point.

[Kristin Winter]

Did you get the original for your airplane or a generic copy? What did they charge you for that?

[Charles Schefer]

Kristin, you are right about the Cirrus wing. Fantastic wing but very high loading of 25lbs / sq-ft. I imagine the Hershey-bar Az-truck wing would be more forgiving of ice. However the FIKI cert SR-22 model is very capable in ice and it has an advantage in run back icing. I've flown one thru moderate-heavy icing conditions and the TKS kept the whole airframe clean. That said it wasn't a by choice encounter. I believe ALL aircraft especially light aircraft should aggressively avoid icing. The thing I don't like about TKS (other than the mess it leaves dripping on the hangar floor for days) is that you can run out!

- Charles

[Kristin Winter]

I always considered the deicing equipment as just incrementally better than none at all. My strategy for a flight was the crucial element, deiced or non-deiced. Deiced just gives me a little bit longer to be in it so I can climb or descend through a bit thicker, nastier layer than I might otherwise. I have put ice on an airplane hundreds of times, but never gotten to where the aircraft was thinking about not flying any more or requiring me to sacrifice altitude to maintain speed.

I have always thought the FAA went about icing all back asswards. Since there is no such thing as a light airplane, or maybe any airplane, that is impervious to ice, regardless of how it is equipped, it seems to me that we need "known icing" pilots. Training would save more lives. Instead, all you get from the FAA is "don't fly in it". They don't tell you what kind of ice to worry most about. How to have a strategy or how to figure your escape routes.

I will give you the point about run back ice, but all it will likely take is an altitude change to get the ice to do something other than start to build a ridge behind the boots. Again, this is something that ought to be taught. There is a world of difference between half an inch of rime on the leading edge and ice building a spoiler on top of the wing.

Running out of fluid would be ugly in a Cirrus. I wonder if the parachute is FIKI certified.

[N8632Y]

Training for "Ice" a great idea, and maybe an endorsement like high altitude, just another atmospheric phenom....
My old buddy fly in Alaska for 25 yrs, never with de ice equip, mostly Aztecs.
He said they were great, he would talk of cycling the prop, or quick pitch changes to bust off ice. He once had his gear iced and stuck up. Told the tower he was gone out over bay for awhile till the warmer air melted the iced up gear. Yes, it's the pilot that makes or breaks the plane, not vice versa.

steve

[Charles Schefer]

100% agree on the training point.

[Charles Schefer]

One other comment for discussion that just occurred to me regarding which AFM is used as the official AFM (and I realize this is starting to stray from the original purpose of the thread)... I have been told that if you have a newer airspeed indicator in knots instead of mph that you must also have an AFM in knots. Assuming that is correct (I have not throughly researched it) then if you have... say an Aspen PFD displaying knots then you need the newer ICS AFM as your official AFM with knots for various reference speeds in the book.

Thoughts?

[Kristin Winter]