Just prop deice... why?

[CruisingSpeed]

Anyone know the advantage of JUST having prop de-ice, say on a TB20...
I know it is better than nothing when you enter icing conditions inadvertently... but you are not certified for flight in icing conditions which you would be with a full TKS system and certification.

So with a prop deice you would have to stay well clear of icing conditions anyway, and if you enter icing then yes, your propulsion system might stay alive, but what use would that be when your airframe ices up...

Who decided on fitment of a prop de-ice only, and for what reasons?
I guess this gives you no benefit in dispatch capability, but eases the mind when operating in marginal conditions... any thoughts?

[IO540]

I have this and it is excellent.

The idea is that no matter what else collects ice, you will have power. This is obviously important. Depending on the aircraft, it can take a LOT of ice before you lose significant lift but it will take very little ice on the prop to seriously clobber the ability to climb, especially if you are already at say FL100+.

You need power to climb, and climbing is one of the escape routes (depending on what the TAT happens to be; if it was say -2C and there is 5000ft of safe air below then I obviously wouldn't climb). If you get serious prop imbalance (due to ice) then you may have to reduce power and you are stuffed; the only way is down.

As for despatch capability, and known ice certification, the whole subject of what constitutes "known ice" (particularly in the UK where "icing in cloud" appears on every F215) has the potential for a very long thread indeed....

The general idea with flight into potential icing is that you must always have an escape route. A deiced prop gives you more options in that department.

[CruisingSpeed]

Wow, great post, just what I was looking for!

What is "a LOT of ice" before you lose significant lift, if I may ask?
Most I had was half a centimeter on the leading edge, with no noticeable performance degradation. That was incidentally the point when I was very happy to switch on the de-ice function of the TKS... :O

[IO540]

The answer must depend on the aerofoil.

On a TB20 I've had up to about 8mm of mixed clear+rime and there was no noticeable IAS drop.

You need to switch on TKS before entering IMC when the temp is below zero, otherwise the orifices can clog up with ice. I would guess this could play havoc with a prop if some blades got it and not others. This is less of a problem with the prop TKS (the full TKS system has tiny holes on the leading aerofoil edges). I always switch the prop TKS to max (never use the low flow option) when in IMC below zero.

Prop TKS also keeps the front window ice free; works brilliantly and is operational in about 1 minute from switching it on.

Of all the "uncertified" (and therefore supposedly useless) gadgets one can get for a plane, prop TKS is one of the best. It's also relatively cheap, 1/10 of the cost of full TKS. Others are perhaps a Shadin flowmeter (linked to the GPS) and an EDM700.

[bpilatus]

IO,

8mm and no difference! Are you sure it was ice. A dose of rime on the leading edge will cause most machines to suffer and I speak from experience. A cavalier attitude tempts others to ignore most sensible advice which must be stay well clear of icing conditions. Might I suggest that pilots consider the possibility of icing conditions before they depart. A matter I touched on in the recent debate about the JAA/IR. I presume you are not such a qualified pilot.

[IO540]

I was trying to provide a useful answer to a question, BP, and I did say any "data" like this is aerofoil specific.

On the legal issues, and personal attitude to risk, one can pontificate for ever, without increasing anybody's knowledge. Something online forums (fora?) are excellent at.

It was white with clear bits, rough looking, came from apparently nowhere and was getting thicker. It might have been frozen Dulux emulsion, I suppose, but I've seen it quite often. Also, it always seems to melt when the TAT passes through 0C into positive. And yes I have an IR, though it is only the sort which comes free if you collect 25 vouchers from fag packets (the same one which perhaps 95% of the world's entire population of private IR pilots fly with).

:O

[bpilatus]

You might consider the JAA/IR. It will improve your understanding of IFR flying. If the full course is too onerous and I appreciate this may be the case for most private pilots then why not consider the Met theory material.

[IO540]

I was pulling your leg, BP, about the Dulux emulsion.

With your JAA IR, you should know it all, while regrettably refraining from posting something that is useful to read.

Anyway, there are two ways to approach flight into potential icing

(1) Never fly into potential IMC (i.e. IFR) at a level where the OAT is forecast below zero, unless the plane is certified for known ice (and what exactly does that mean - think about that one, not just legally but more to the point practically)

(2) Understand a bit about one's aircraft's capability, understand where 3D weather data can be obtained from, examine the data carefully, and plan the flight with appropriate escape routes (usually a descent into warmer air, while remaining above the MSA).

Option (1) grounds all non-KI planes for some 6 months of each year in N Europe, for IFR (airways) flight.

It's amazing how many JAA IR holders sit around internet forums, having absorbed all that knowledge and having sat all those exams, yet seem so economical with their time when it comes to passing on that fountain of knowledge onto others.

If you had written some technical stuff on how different aerofoils are affected by ice (for example) that would be something else.

Anyway, any more than 5mm of ice (or whatever the white stuff was?) I would be executing my Plan B.

[nipper1]

Buy and read John C. Eckalbar's 'Flying High Performance Singles and Twins'. The final chapter is devoted to icing and there is much else besides that will be of interest.

You can get it from Sporties or one of the other US Pilot Shops if it is not readily available in the UK.

[CruisingSpeed]

Good to have someone spit out some useful info IO, appreciate it.

How stupid do I look now with my JAA/IR asking silly questions about TKS systems, but when blasting along on a 744 with all that hot air available you just don’t think about prop de-icing. I have also never experienced prop vibration due to ice, and nooo, I am afraid it probably won’t help much when it might happen to have read in some JAA theory course that you should never be there in the first place. :ooh:

When faced with a variety of equipment on a small aircraft and a trip to fly in cold weather you become very mindful about what is useful and for what reasons, in fact I have just been offered a prop de-iced aircraft to replace my usual aircraft furnished with full TKS, which has just gone tech. :uhoh:

By the way, I would confirm from personal experience that the de-ice function is not really there to get off any accretions that have already formed. Since there is also an anti-ice switch position one would think that one prevents and the other actively REMOVES ice… however I too had the impression that the orifices clogged up and that not much happened until I peeled off the ice by hand after landing. := I would like to think though that the orifices SLOWLY melt free when the de-icing agent is constantly pressed out by the pump.

The full TKS also offers a windscreen sprayer… suppose that one may be left in idle if you say that the prop de-ice does the same job effectively.

Might be what some call a non JAA compliant cavalier attitude, but holding the qualifications, operating suitable equipment and (like IO says) having plan B, tentative exposure to icing might make you a more experienced and therefore safer aviator. :ok:

[IO540]

I have zero personal experience of the full TKS system but I understand from those that have it that the anti-ice position does have a use, in that it prevents the little holes getting clogged up.

I would question the value of the anti-ice position on the prop-only TKS system. There are no "little holes" to clog up; the smallest orifice is about 2mm diameter.

The thing is that none of these systems, known ice certified or not, are 100%. The full TKS is reported as really really excellent under serious icing conditions and much better than rubber boots. I've met pilots who fly in the most northern bits of Europe with it, all year round. But the fluid won't last for ever, so the name of the game remains the same as always: get into VMC, above or below (above is nicer, you get sunshine and a TB has a cr*p heater :O )

The fluid in the prop-only version doesn't last long; only about an hour I think, but no plane wants to hang in there collecting ice for that long. A TB20 gives you the option (with an IR) of flight planning a flight at say FL160/170 and that should take you above en-route clouds most of the time. Nevertheless, icing remains a real flight planning issue, all around the year, if one has to go up/down through it. You could get a TB21 (cert ceiling 25k) but then you end up with a W&B issue due to the size of the oxygen bottle :O (work it out; 4 pax, masks not cannulas). If I was doing this properly while working down to a sub-turboprop budget, I would get a TB21 with full TKS.

Funnily enough, a TB20 with full TKS, G-reg is KI cert while an N-reg one isn't (last time I checked). Clearly, they have different ice in the USA :O

NASA have a good icing course on their site http://aircrafticing.grc.nasa.gov/courses.html but you've probably seen that one.

This site http://ows.public.sembach.af.mil/ has nice icing region diagrams under Flight Hazards.

This site http://pages.unibas.ch/geo/mcr/3d/meteo/ under Animated Soundings gives some forecasts of cloud tops and temps (skew-t).

This site http://weather.uwyo.edu/upperair/sounding.html under Europe, Skew-T GIF has the actuals but they are usually a bit late to be useful for planning.

This is the standard GFS site http://www.arl.noaa.gov/ready/cmet.html where you can get, among a pile of other stuff, variation of temp (at a given millibar level) with time.

Of course none of this data is CAA compliant; they like you to use the Met Office faxback facility...........

[bpilatus]

Anyway, there are two ways to approach flight into potential icing
(1) Never fly into potential IMC (i.e. IFR) at a level where the OAT is forecast below zero, unless the plane is certified for known ice (and what exactly does that mean - think about that one, not just legally but more to the point practically)

I only read the first paragraph, you confuse IMC with IFR. The two are entirely different and often confused, the former is weather related and the latter is flight rules. It is often possible to fly in cloud (I did it just a few days ago) in temperatures below 0 without picking up ice.

[IO540]

I was referring to the fact that if you file an IFR flight plan you may have little option but to enter IMC. This is getting silly....

[bpilatus]

I agree it is getting rather tedious. It wouldn't be quite so bad if you refrained from talking about matters on which you appear to have little knowledge.

Even your last post is not clear. Any pilot (with or without an IR) can file IFR. IFR does not mean entering IMConditions, indeed IFR is possible by the quad rule. Sit back take a deep beath and consider the content of your posts. I have also noted your tendency to get aggresive with those that endeavour to correct your mistakes. It takes me back to my school days.

[2Donkeys]

I would generally endorse IO540s views on the usefulness of TKS prop-deice. The value is entirely associated with keeping your powerplant useful at a time when other parts of the aircraft may (however inadvertantly) be picking up lots of ice. It amounts to an imperfect get-out-of-jail card, rather than a mechanism for flying into icing conditions deliberately.

It does also have the additional benefit (on a TB20) of keeping much of the windshield ice free, as well as a few feet of the leading edge on both sides.

Where my experience departs from that of IO540 is when he talks about the ability of the TB20 to carry ice. My experience has been that the TB's performance tails of quite quickly with ice, with a measurable drop in IAS. The quid-pro-quo is that being relatively thin-winged, the rate at which ice acretes is somewhat slower than in types with a thicker wing section. Swings and roundabouts.

bpilatus - your language skills continue to improve, I see ;)

[bpilatus]

And as any IR pilot worth his salt will know rime gathers quickest on the smaller diameters, OAT probe, tail/ fin leading edges and main wing leading edges, particularly thin winged types.

[nipper1]

I often fly IFR in IMC at levels below the airways with a UK IMC rating without the benefit of any de-ice equipment. Freezing level at the flight planning stage and the OAT guage in flight are both considered rather important.

Returning to my home field for an IFR rejoin at (typically) 3000 feet I am often requested to 'climb 4000'. If the OAT is ner to freezing at 3000 feet I politely request 'wish to remain below 3000 due icing' and have never had a problem.

Without getting into another debate about the wisdom of flying in IMC without a radar service (I have long ago decided that I subscribe to the big clouds theory) do any more exzperienced forumites have any opinions on this? I would be especially interested to hear an ATC view.

[slim_slag]

As for despatch capability, and known ice certification, the whole subject of what constitutes "known ice" (particularly in the UK where "icing in cloud" appears on every F215) has the potential for a very long thread indeed....

A very short thread actually. If you are exercising the privileges of your FAA IR, and this is especially relevant for those people where the ink is not yet dry on the temporary certificate ;) , "forecast ice" means "known ice". If the forecastsays "icing in cloud", then using an FAA IR you may not enter any cloud in the plane you are describing.


The general idea with flight into potential icing is that you must always have an escape route. A deiced prop gives you more options in that department.

No, that brand new IR you are using is issued by the FAA, you have to do what they say, and they will take it off you if you fly into potential icing areas in a non known ice plane. They do this because they think what you are doing is 'careless and reckless', and so do I.

You can attempt to reinterpret this how you like, and I am sure you will as you are going to do what you want to do anyway, but Federal case law is very clear. Forecast icing or potential icing = known icing. You may be in the UK but the Feds can still pull your certificate. They did in the following cases.

Administrator vs Bowen
Administrator vs Irmisch
Administrator vs Groszer

[2Donkeys]

bpilatus - True for rime ice, but although generalising is dangerous, rime is not the sort of ice to strike terror into the heart of a pilot at first sight. Rime normally provides escape time...

[bpilatus]

Where my experience departs from that of IO540 is when he talks about the ability of the TB20 to carry ice. My experience has been that the TB's performance tails of quite quickly with ice, with a measurable drop in IAS. The quid-pro-quo is that being relatively thin-winged, the rate at which ice acretes is somewhat slower than in types with a thicker wing section. Swings and roundabouts.
bpilatus - your language skills continue to improve, I see ;)

I don't know much about the TB20 but, as stated above in my earlier text, am surprised that someone elses experience could be so different.

2D, you sound like an experienced pilot, I presume you have some knowledge of the TB20.

[2Donkeys]

I presume you have some knowledge of the TB20

I think I can probably hold my own.

[bpilatus]

I quite agree about rime although in time it can accumulate and become an issue. Even a light spread of rime (I appreciate this may be contrary to that posted above) will have an adverse effect on performance. A decent dose of clear ice will have dramatic effects on performance. Ice can restrict the movement of control surfaces with obvious consequences, to continue flight into clear icing conditions is suicidal.

[2Donkeys]

We are in complete agreement.

Clear ice can be a serious problem even on de-iced aircraft because of its habit of running back and forming out of reach of de-icing equipment.

[S-Works]

so in the same vain that means nothing but a de-iced aircraft can enter cloud in the UK as EVERY 215 carries an ice warning..........

I think the barrack room lawyers might be getting a bit silly now.

[2Donkeys]

From an FAA standpoint, it is true that where ice is forecast, known icing is deemed to exist. As a result, to fly a route involving such forecast conditions in an aircract without known-icing certification places you in violation.

If you fly an N-reg in the UK on the strength of an FAA pilot certificate, then you face the largely theoretical risk of having your certificate suspended (not "pulled") for flight into such forecast conditions. This does make the wording on our 215s problematic.

Fortunately, few people voluntarily fly into icing conditions that are likely to raise their profile sufficiently to merit any regulatory action. Of those that do, few live to endure the wrath of the regulator.

2D

[IO540]

Sticking to barrack room law chat for the moment

"If you fly an N-reg in the UK on the strength of an FAA pilot certificate"

a) quite a lot of FAA IR holders also have a valid UK IMCR, so provided they are below Class A they can fly IFR (in IMC as applicable) in UK airspace on their UK license, and

b) on a typical IFR flight to another country, it is not unusual to remain below Class A, or even OCAS entirely, when within UK airspace (for simplicity of routing), and once outside the UK (when any IFR flight will be on the FAA IR privileges) the "known ice" argument comes down to whatever weather forecasting service(s) are applicable to the airspace one happens to be passing through, and what they say about icing...

Weather forecasting services are like the old joke about British Standards - there are so many to choose from :O

[slim_slag]

2D,

I see this forum as a virtual hangar where 99% of the stuff is just hangar talk, and in all the hangars I've spouted b-sh1t in, 'pulled' means the big bad nasty regulator gets to take your privileges away. So yep, it can be called suspended too :)

Aren't most regulations theoretical until the time you get caught? If you look at the judgements in the cases I cited, it's very clear that 'those who enforce these regulations' consider flight into possible icing as a very serious safety risk. There isn't a FAR which specifically covers this, and these people got busted under 'careless and reckless'. I think it's sensible to take this as more that theoretical. First because the NTSB undoubtedly know more than me about safety and they say it's unsafe, and less importantly they can suspend my certificate, and then it's going to be a pain telling that to my insurance company.

Cheers

IO540,

You are still in an N-reg. I know you really don't like it, but the rules apply to you.

[2Donkeys]

Slim_slag, I hate to give the impression of beating you up on these threads, but when you say

There isn't a FAR which specifically covers this

would I be right in assuming that you have overlooked 91.527?

On the "pulled" point, I was attempting to make a subtle distinction between revoked and suspended. There are relatively few things you can do which give the FAA the right to revoke your licence, and many which may lead to a suspension. "Pulled" didn't quite cover that subtlety for me. :)

2D

[IO540]

"You are still in an N-reg"

Yes, quite true. However, I will probably be below the 0C level while in UK airspace.

Just illustrating that this isn't cut and dried, SS. How much do you know about which weather forecasting services apply to different countries around Europe?

I happen to read a lot of debates in U.S. pilot newsgroups (where there are a lot more active IFR pilots than here) and they too are concerned about "icing" AIRMETs that cover large sections of the USA - a situation as patently divorced from reality as the UK F215 one.

[slim_slag]

2D,

I don't think you are beating me up, we may be having a debate but I don't think either are beating the other one up. That is definitely not my intent.

That FAR you quote, 91.527, (Subpart F) only relates to Large and Turbine-Powered Multiengine Airplanes and Fractional Ownership Program Aircraft. Although there may be pretend airline pilots around these parts, we are talking about little planes here which are not certfied for flight into known ice :)

They will bust you on 91.13 (careless and reckless), and in my opinion for very good reason. Is the plane placarded against this, there is another reg.

[2Donkeys]

Slimslag

I just wanted to test your assertion that no FARs cover operation in icing conditions.

So far as taking action against light aircraft is concerned, the FAR normally invoked is 91.9(a).

2D

[High Wing Drifter]

On the subject of TBs and Icing:

http://forums.flyer.co.uk/viewtopic.php?t=19997&highlight=tb20

[slim_slag]

2D,
I never asserted that 'there are no FARs that cover icing operations'. To use your word, I asserted that 'There isn't a FAR which specifically covers this' and as we are discussing a TB20, I humbly submit that I am correct. But enough bickering, lets get back to beating each other up :)

You can only use 91.9(a) if the placard exists, which is why I asked the quesion. I'd have to look it up but that regulation only came in during the 1960s? I guess it was a stupid question as your plane will have been built since then.

As for which FAR they will use, I think they will use 91.13, I say that because they have (PDF) Administor vs Boger (http://www.ntsb.gov/alj/O_n_O/docs/aviation/4525.PDF)

Also Administrator vs Grozer (http://www.ntsb.gov/alj/O_n_O/docs/aviation/3770.PDF) where they used 91.13 as well as 91.9 (or the equivalents at the time)

Cheers

[DFC]

IO540's argument about the UK forecast charts has some merit and I agee with him that the checking of the weather pre-flight should not be simply confined to asingle source.

The UK charts issued by the met office have a big "disclaimer" for want of a better description that causes most of these problems. These "disclaimers" are more about covering the met office by stating the rather obvious than providing usefull services.

"Cloud on hills. Moderate ice and moderate turbulence in cloud" Is far too general to be usefull.

To say that IO540 would have his nice new IR suspended/revoked for executing an IFR flight in cloud with such an "icing forecast" would be like saying that IO540 should have the IR revoked/suspended for flying in cloud that contains large amounts of mountain. The authorities would have to take a closer look at all the available information (just like IO540 does pre-flight).

However, to pick up on 1 item - using an IMC rating on an N reg aircraft - not possible to fly IFR on an N reg with an IMC rating because the regulations require the pilot to comply with the FARs or local regulations whichever are the more restrictive and the FARs require an IR for IFR flight. Not to mention that the FAA would take a very dim view of a pilot using foreign national non-icao paperwork to circumvent requiremrents put in place for safety.

What single engine aircraft are certified for flight in icing conditions? (That means a flight manual allowing flight in light ising conditions or worse - not simply manufacturer promotional info / optional equipment)?

Finally, it is very reasonable to be in a situation where one plans and flys an IFR flight but plans to and does remain clear of cloud (icing being one very good reason) for that another being CB activity but no weather radar. Example - climb clear of cloud, cruise at FL65 with could tops at FL60 - most definitely not VMC and not VFR and then visual descent to destination.

However, regardless of what has been said, icing of any sort is a killer and no one in their right mind would intentionally fly in icing conditions regardless of equipment if there was an alternative (which may be stay on the ground).

Regards,

DFC

[2Donkeys]

DFC

I agree with the principle that the 215 alone is problematic (I have put it no more strongly than that). To the extent that the 215 forecasts icing in any and all cloud, if your cruising level involves flight in cloud you have a potential problem.

The FAA enforcement system, like our own works on the basis of challenge (often, but not exclusively after an event). If you are challenged, the onus will be on you as the Commander to demonstrate which sources of weather you placed reliance on, and why they were sufficiently persuasive to allow you to disregard the blanket nature of (in this instance) the 215.

Certain forms of report (such as PIREP) have been tested in court many times and found not to be of sufficient value to overturn a forecast. Other, better forecasts from different sources (Frankfurt is good), seem to me to offer a much better defense.

The statement on the 215 is a thorn in the side of the FAA IFR Flyer, but to put it any stronger than that would be a mistake in my view.

2D

[slim_slag]

The piper mirage is single engine piston with known ice certification.

Found this Avweb Article (http://www.avweb.com/news/airman/184265-1.html) Read it and make your own minds up what is and isn't 'problematic' :) Cheers

[IO540]

"using an IMC rating on an N reg aircraft - not possible to fly IFR on an N reg with an IMC rating because the regulations require the pilot to comply with the FARs or local regulations whichever are the more restrictive and the FARs require an IR for IFR flight"

DFC, this one has been thoroughly checked out (done to death, in fact) and fortunately you are incorrect. The IMCR privileges are valid in an N-reg.

Getting back to icing, the UK Form 215 "forecasts" icing in all cloud (i.e. regardless of temperature) which is patently daft as it prohibits all flight in IMC unless the aircraft is K-I certified ... think about that one :O

Just how anally retentive can one get? I know this is aviation, where there are more anally retentive people than in any other human endeavour (endeavor if in the USA) but this really is going a bit far.

[Send Clowns]

Having recently flown a lot in cloud, much of it below zero, over the last couple of months I can categorically state that icing is unpredictable, at least with the info available to us, so until you are there, or someone else has reported icing, then known icing (using the words as common language, rather than a legal definition) cannot exist.

I have encountered icing, not a problem since the aircraft is cleared for flight in known icing and the deicing systems functioned to keep the aircraft flying efficiently, but only on about half of the occasions I have been in cloud at below zero. In most of those cases the airframe icing did no more than slow me down by about 5 or 10 kts (I never allow prop icing to occur, but with boots I have to let the surface ice accrete). I have used the boots to recover performance, not because it was vital to flight safety. There has been one occasion when the icing would have been a hazard had I not used the deicing kit, and then if I'd have called an emergency London would have let me climb the 500 feet I needed to clear the cloud.

One thing I would say is if you are picking up icing don't use the autopilot! You need to know how the aircraft feels.

I would say then that anti-iced props are useful on their own. I would not like to fly with an assymetric prop, let alone two!

[High Wing Drifter]

Does anybody know why the (or is it a particular model) Beech Baron is not certified for icing, even though it has wing and prop de-ice?

[bpilatus]

Because like virtually all other light machines the equipment is (very) limited in its usefulness.

[2Donkeys]

Some Barons are not Known Icing approved because of their age; there having been no concept of known icing approval at the time of their manufacture.

Some Baron owners lived in sunny States and didn't select the Known Icing Option, even when it was available.

Many Barons are known icing approved.

[bookworm]

A very short thread actually. If you are exercising the privileges of your FAA IR, and this is especially relevant for those people where the ink is not yet dry on the temporary certificate ;) , "forecast ice" means "known ice".
This doesn't tally with the AIM, slim_slag. (Table 7-1-8)
Known Icing Conditions
Atmospheric conditions in which the formation of ice is observed or detected in flight.
Potential Icing Conditions
Atmospheric icing conditions that are typically defined by airframe manufacturers relative to temperature and visible moisture that may result in aircraft ice accretion on the ground or in flight. The potential icing conditions are typically defined in the Airplane Flight Manual or in the Airplane Operation Manual.
I believe the definition postdates all the cases you cite, and one motivation may have been to clarify the rather screwy interpretation of "known" that the ALJs had adopted. That interpretation came from a need to demonstrate that some aspect of the law was enforceable against pilots who had done some very stupid things.

[slim_slag]

HI bookworm,

What the AIM actually says is.

Known Icing Conditions
Atmospheric conditions in which the formation of ice is observed or detected in flight.
Note-
Because of the variability in space and time of atmospheric conditions, the existence of a report of observed icing does not assure the presence or intensity of icing conditions at a later time, nor can a report of no icing assure the absence of icing conditions at a later time.

The AIM is advisory. Do you have any case law which is more recent than the case law already established? I think it was established that a PIREP is anecdotal. Besides, I mentioned forecast icing, not potential icing.

[bookworm]

I think it is abundantly clear from the AIM that the FAA does not equate "known icing" with "forecast icing". If I'm not to look to the FAA for an interpretation of the terms in the FAA-approved and -originated AFM, what use is the AIM?

"Forecast icing" does play a part in for Part 135 operators in 135.227.

I'm not aware of a case of a Part 91 pilot having their certificate suspended in circumstances that were other than very poor airmanship and a lamentable lack of appreciation for the risk management of icing. If I were a UK-based pilot operating an N-reg in the UK on an FAA certificate, I'm not sure that the rather weird interaction between NTSB case law and Met Office icing warnings would be at the top of my priority list.

[slim_slag]

I think it is abundantly clear from the AIM that the FAA does not equate "known icing" with "forecast icing". If I'm not to look to the FAA for an interpretation of the terms in the FAA-approved and -originated AFM, what use is the AIM?

To answer your first question, what use is the AIM

d. This publication, while not regulatory, provides information which reflects examples of operating techniques and procedures which may be requirements in other federal publications or regulations. It is made available solely to assist pilots in executing their responsibilities required by other publications.

AIM Preface (http://www.faa.gov/ATpubs/AIM/Preface/aim-pol.html) Does that make sense? It's advisory, one should follow its advice if you know what's good for you, but it is not binding.

Who has ever said the FAA equates known icing = forecast icing? I haven't, I have said the NTSB have, and they are the ones with the judges who will suspend your ticket.

I'm not aware of a case of a Part 91 pilot having their certificate suspended in circumstances that were other than very poor airmanship and a lamentable lack of appreciation for the risk management of icing.

The following comes from an NTSB order denying an appeal against suspension for careless and reckless behaviour during a part 91 operation.

We stated that "known" does not mean a near certainty of icing conditions, only that icing conditions are being reported or forecast

Administrator vs Groszer (http://www.ntsb.gov/alj/O_n_O/docs/aviation/3770.PDF)

Is that clear enough for you? Known = Forecast

If I were a UK-based pilot operating an N-reg in the UK on an FAA certificate, I'm not sure that the rather weird interaction between NTSB case law and Met Office icing warnings would be at the top of my priority list.

That is an opinion which you are entitled to. I have cited five NTSB cases to back up my argument. The arguments against me have been backed up with opinion, a misquoted table from the AIM which if anything strengthens the case that known icing is impossible to quantify, and a FAR that doesn't apply. Do you have anything concrete which you can add to back up your argument which is clearly based upon your own opinion and nothing stronger.

Cheers

[bookworm]

Who has ever said the FAA equates known icing = forecast icing? I haven't, I have said the NTSB have, and they are the ones with the judges who will suspend your ticket.

You may want to read the front page of the appeal cases that you cite more carefully.

[bookworm]

That is an opinion which you are entitled to. I have cited five NTSB cases to back up my argument.
You've cited 5 cases that predate the FAA defining the term "known icing conditions", which had not previously been defined and was open to interpretation by the ALJs. If you could find a case after 2001 in which the FAA took action for violation of the AFM limitation against a pilot who flew in forecast icing condition that were not known icing conditions according to the AIM, that would be much more compelling.

[boomerangben]

I cannot believe what I am reading here. Are pilots really flying in known icing (ie IMC/visible moisture above the 0 deg C thermocline) in light singles with no icing clearance?

Do they have pitot heat?
Are the Static ports heated?
Are they aware of the weight of ice that might accumulate?
Are they aware of how suddenly and how quickly ice can accumulate?
Have they seen the damage chunks of ice do when they disembark?
Are they sure that control surfaces won't freeze up?
Can you accurately measure how much ice you have accumulated?
Are you sure the carb heat is still doing its job?

Maybe you can get away with playing in light icing, but you can't be sure that the next bit of cloud isn't an iceberg waiting to happen. Quite frankly IMHO icing is one of the most dangerous aspects to IF.

[n5296s]

What single engine aircraft are certified for flight in icing conditions? (That means a flight manual allowing flight in light ising conditions or worse - not simply manufacturer promotional info / optional equipment)?

There are quite a few. The Mooney Bravo is available KI, so is the Cessna 210 (well, was... there are still plenty about). The TKS people do KI
conversions for several models too. There are others, just leaf through
Trade-A-Plane. I believe that when the Columbia 400 deice becomes available it will be KI, though I'm not certain.

The difference between KI and non-KI is pretty small. For example TKS will sell you either on a 210, with about a factor of two in the price. Primarily KI requires:

-- duplicate pump (for TKS) and electric backup (i.e. second alternator)
-- must have been testing in icing conditions, i.e. flying behind a tanker. Now THAT must be an interesting job...

Ice is the main reason I've pretty much given up trying to use the plane to get anywhere serious in winter, after having to leave it in Las Vegas for a week and fly home (and back there) commercial due to the risk of ice.

n5296s

[IO540]

Do they have pitot heat?

What do you think?

Are the Static ports heated?

Not normally a problem where they are.

Are they aware of the weight of ice that might accumulate?

If you load your plane like the average Warrior with 4 people crossing the Channel on a sunny Sunday on the way to LeTouquet, that might well be a problem :O

Are they aware of how suddenly and how quickly ice can accumulate?

In stratus cloud, not all that "suddenly"

Have they seen the damage chunks of ice do when they disembark?

Disembark from where?

Are they sure that control surfaces won't freeze up?

They would if you do nothing about it

Can you accurately measure how much ice you have accumulated?

You could climb out with a tape measure, I suppose.

Are you sure the carb heat is still doing its job?

Now, that one gives the game away. I hate to be impolite but you should get back to FS2004 ;)

Carb icing is not the same thing as structural icing. Carb icing is caused by the temperature drop in the carb venturi. Structural icing is caused by flying through air containing supercooled water droplets.

[boomerangben]

Do they have pitot heat?
What do you think?
I have no idea, I don't fly small fixed wing.
Are the Static ports heated?
Not normally a problem where they are.
But it could be a problem?
Are they aware of the weight of ice that might accumulate?
If you load your plane like the average Warrior with 4 people crossing the Channel on a sunny Sunday on the way to LeTouquet, that might well be a problem :O
Agreed the weight of ice is relatively light, but it accumulates where loads are not designed for and would change moments of inertia and hence handling
Are they aware of how suddenly and how quickly ice can accumulate?
In stratus cloud, not all that "suddenly"
So you only fly in stratus cloud?, Never in cumulostratus? Do you have radar to check for unforecast large CUs, TCUs, CBs?
Have they seen the damage chunks of ice do when they disembark?
Disembark from where?
I am not familiar with your a/c type so I couldn't say for your case. But I have seen what damage chunks of ice have done to engines and airframes.
Are they sure that control surfaces won't freeze up?
They would if you do nothing about it
So there is a risk of frozen control surfaces?
Can you accurately measure how much ice you have accumulated?
You could climb out with a tape measure, I suppose.
You are not taking this seriously are you? All the aircraft I have seen with an icing clearance have a means of measuring ice accumulation.
Are you sure the carb heat is still doing its job?
Now, that one gives the game away. I hate to be impolite but you should get back to FS2004 ;)
Carb icing is not the same thing as structural icing. Carb icing is caused by the temperature drop in the carb venturi. Structural icing is caused by flying through air containing supercooled water droplets.
First of all I use a proper computer that won't run FS2004;). Besides real flying is far more fun. Having had the pleasure of flying an aircraft with a carb heat gauge, I have noticed times when the carb heat needle doesn't get out of the yellow, even with full carb heat. OK so it is rare, but might well be an issue, depending on the sort of a/c you are flying.
I don't particularly care whether or not you fly in icing and whether you licence and/or aircraft allow it. I am merely pointing out various points that are brought up when icing is discussed. If you are confident that you have the experience, qualifications and equipment to answer all these points (and others I might have missed) then good luck to you.

[IO540]

Ah, a Mac or Linux user, I presume? :O

The general idea with icing, as I have written before a number of times, is to always have an escape route (generally a descent into warmer air) and a plan for the flight which avoids IMC altogether if the temperature at the relevant level is in the 0C to -15C band.

Nobody wants to sit in IMC for hours, whether you have a KI aircraft or not. It's boring at best, unpleasant for passengers, freezing cold because most unpressurised planes don't have a heater that can give you +20C inside with -15C outside and no solar gain, and eventually you may collect too much ice no matter what and then have to do something about it.

But with a decent plane (say TB20 and similar) you can flight plan a flight at say FL160 (obviously you need an IR for that, in most places, due to Class A) and this would usually take you into VMC. Any freezing IMC encountered en route is dealt with by asking for a climb or a descent "due to icing", etc before you enter it. Then, you have to make sure that the climb and descent at the ends is OK and often this is what drops the spanner into the works and prevents you going - not the en route section which is relatively easier to deal with.

Obviously you need oxygen.

If you are flying a C150 or even a PA28, you can't do any of this, because the thing won't be able to climb high enough to be VMC on top with reasonable probability. It also doesn't have the range to make it worth doing. A plane with 1000nm range (with IFR reserves) can take you from a CAVOK area, over 2 or 3 completely different weather systems, into another CAVOK area. One problem here is that perhaps most people reading this are indeed flying spamcans which are unsuitable for this kind of flying in the first place, but that should not prevent a reasonable debate, absent of "ice will kill you, must avoid it totally" hysterics.

As to the details: every half decent plane has a heated pitot tube, never heard of static ports icing up (and there is alternate static from the cockpit), W&B is not a problem with ice until you have so much of it you are going to plummet anyway due to having no lift, decent IFR tourers, especially ones that come in KI versions, have big enough gaps around the control surfaces, carb icing is nothing to do with any of this (also any half decent plane is fuel injected and doesn't have a carb, but could get intake icing for which there is an alternate inlet), and one would avoid flight if CBs are forecast (you wouldn't fly through a front, for example, in potential IMC) unless VMC can be reasonably assured in the relevant section. Various other things like that.

I don't mean to minimise this subject; just trying to make the point that with decent planning it isn't something that is going to kill you, because you had your escape route planned before you set off.