IFR + Anti Ice

[boomerangben]

Just a dream, but is there light (4 seater?) aircraft that has anit/de ice facilities and therefore be an effective all weather (ish) go places machine? And how big would the lottery win have to be?!!

[S-Works]

there are a number of aircraft out there that have both anti and de-ice. 2/3 of the twins that I fly have anti ice in the form of a chemical release system and one them also has de-ice with inflatable boots.

The Cherokee 6 I fly has electric anti ice. The big problem is weight, all of these systems are heavy and subsequently need a lot of horse power.

The new Da42 twins that are being delivered to AFT at Coventry have chemical de-ice. Looking forward to flying them sat up in the airways on o2 at FL180!

[ThePirateKing]

Cirrus SR22 can be fitted with de-ice. Not sure about the SR20.

TPK:ok:

[Davidt]

Commander 115's have TKS deicing as an optional extra.

If the factory comes back into production yours for nearly$1/2 mil.

[bookworm]

Over the 10 years I spent flying a (non-deiced) Mooney IFR in the UK and W Europe, my scrubbed trips were caused by, in descending order of frequency:

1) Strong (often cross-) winds
2) Convective activity, thunderstorms
3) Risk of icing
4) Poor vis or low cloud

If you want all-weather, having something that handles 30-35 kt crosswinds and gets over all but the worst convection is, IMO, more important than the sort of de-/anti-icing capability fitted to light singles and twins.

[Fly Stimulator]

Cirrus present their system as a get-out-of-trouble one and not something intended to let you plan a flight through known icing conditions. One of the reasons that the fluid reservoir is relatively small is to discourage people from using it in that way.

[IO540]

Bookworm - doesn't that limit you to larger bizjets? Your order of importance is interesting - I know you can do airways whereas I can't (yet) but for me it's usually been the icing level being below the MSA that stops me going in the winter.

One can also get a TB20 or TB21 with full TKS - the extra cost is about £25k on top of the cost of the plane which is about £250k-£280k, plus VAT. TKS is reported to be very effective but duration at max flow rate is of the order of 1 hour, so one needs to be able to climb above the icing region (into an OAT colder than -15C to -20C) which implies a turbo or turbine.

To have more fluid so one could fly in icing for a number of hours, the W&B would be a huge problem because it is very heavy already.

[bookworm]

Bookworm - doesn't that limit you to larger bizjets? Your order of importance is interesting - I know you can do airways whereas I can't (yet) but for me it's usually been the icing level being below the MSA that stops me going in the winter.

OK. That and Bose-x's previous comment about IMC rating training in winter got me doing some homework.

I've looked at Dec 2003, Jan 2004, Feb 2004 -- the three months usually associated with the nastiest UK weather. I've taken the 00Z and 12Z Herstmonceaux soundings to find the freezing level and pulled out those days where it was at or below 2500 ft, which is a typical emergency safe altitude in the southern UK. I've then looked at the Gatwick TAF as being representative of the conditions in that area, and discarded the ones with no significant (SCT+) cloud below that level (the majority of them -- most low freezing levels are just cold clear nights/days). Of those approx 180 data points, I'm left with the following, for which I've examined the sounding in more detail to find the layer tops and lowest temp in the cloud:

00Z 01 Jan 2004
EGKK 010120Z 20014KT 150V230 9999 RA FEW012 SCT018 BKN024 05/02 Q1014 =
Freezing level 2200 ft Tops 3500 ft (-2 degC), though a possibility of freezing precip from higher layers.

12Z 27 Jan 2004
EGKK 271150Z 34009KT 310V010 9999 SCT016 BKN022 04/00 Q1008 =
Freezing level 1200 ft Tops at 3500 ft (-4 degC)

12Z 16 Feb 2004
EGKK 161150Z VRB03KT 9999 OVC016 05/02 Q1031 =
Freezing level 2300 ft Tops at 4500 ft (-5 degC, with above-zero inversion above)

12Z 20 Feb 2004
EGKK 201150Z 07012KT 9999 BKN020 02/M03 Q1020 =
Freezing level 800 ft Tops about 4000 ft (-8 degC)

00Z 22 Feb 2004
EGKK 220120Z 03013KT 9999 BKN018 04/M01 Q1012 =
Thin sub-zero layer, Freezing level 1600 ft warm air from 2500 ft up

00Z 25 Feb 2004
EGKK 250020Z 01008KT 9999 BKN010 02/00 Q1012 =
Freezing level 1400 ft, Tops 3500 ft (-5 degC), further layer at 8000 ft

12Z 27 Feb 2004
EGKK 271150Z 33011KT 290V360 9999 BKN024 03/M03 Q1000 =
Freezing level 800 ft, Tops 3500 ft (-6 degC)

Which of those would provoke you to scrub a trip in the TB20?

[IO540]

BW

The amount of work you must have done to dig up all that deserves a better response than you are going to get here :O

The answer depends on where one is going.

If going around the SE, mostly under the LTMA, then I would scrub all of them. The chance is that one would get away with it 90% of the time, because most of the time, in non-cumulus cloud, the ice buildup is between zero and thin. But I wouldn't take the chance without an escape route, and that would be diverting somewhere completely different.

If going to south of France where the OAT is say 10C higher, and the weather over France was either clear or I was sure of being able to stay VMC on top, then I would depart in all of them. With a de-iced prop, there is no problem in climbing 2000ft through cloud especially if scattered/broken.

If going from the SE to say the Isle of Man then again I would scrub all of them because the conditions will get only worse up north, and one can't go high enough until later in the flight. The exception would be excellent conditions (actual and forecast) soon into the flight in which case it would be worth going around the LTMA.

But you have an unfair advantage: you have cloud tops data. In most of the examples you have, the tops cannot be judged from the ground. This is the big missing item from presently available weather data: a picture of the tops en-route. Bottoms are easy, from TAFs/METARs. The other bit is the 0C level - Form 214/215 is too rough.

Do I need to attend a weather course? :O Come to think of it, I've been looking for one for ages and nobody does anything useful. Lots of basic PPL VFR stuff... What is needed is a specialised course which tells you how to get the data out of GFS and anywhere else and interpret it into an en-route cloud/temperature profile.

[S-Works]

bookworm, wow do you have a life? I am in awe of your ability to dig up facts like this at short notice!!!

IO540 do a JAR IR for the weather answers, 20 weeks of mind numbing details followed by 5 days ground school and whole load of flying!

[bookworm]

bookworm, wow do you have a life? I am in awe of your ability to dig up facts like this at short notice!!!

Just a fun little job for Perl . ;)

But you have an unfair advantage: you have cloud tops data.

Only as an aftercast from the Herstmonceux sounding -- so it's cheating a bit as the F215 may be more pessimistic.

Let me share my thoughts. I think the 00Z 01 Jan 2004 situation is potentially nasty. I don't have the synoptic charts available, but I suspect there was a nasty little warm front that hung around most of New Year's Day, drying up in the afternoon. Not a nice night to be airborne in anything without significant icing protection. However, by 12Z the freezing level was at least 3500 ft.

EGKK 010020Z 18009KT 150V210 CAVOK 06/02 Q1015 =
EGKK 010050Z 19010KT 9999 FEW020 SCT026 BKN050 06/02 Q1014 =
EGKK 010120Z 20014KT 150V230 9999 RA FEW012 SCT018 BKN024 05/02 Q1014 =
EGKK 010150Z 21012G23KT 170V230 6000 RA FEW007 BKN016 04/02 Q1014 =
EGKK 010220Z 20015G25KT 8000 RA SCT012 BKN018 04/02 Q1013 =
EGKK 010250Z 20012KT 9999 RA BKN010 03/02 Q1012 =
EGKK 010320Z 19012KT 9999 RA FEW007 SCT009 BKN012 03/02 Q1011 =
EGKK 010350Z 19011KT 150V230 8000 RA FEW008 BKN009 03/02 Q1011 =
EGKK 010420Z 18011KT 140V220 9999 -RA SCT009 BKN012 04/03 Q1009 =

I also think the 00Z 25 Feb 2004 situation was potentially nasty. However, with a bit more context, I don't think this layer is likely to be mistaken for a major icing hazard.

EGKK 242050Z VRB03KT 9999 SCT032 OVC065 04/03 Q1011 =
EGKK 242120Z 27003KT 9999 FEW018 SCT036 OVC070 03/02 Q1011 =
EGKK 242150Z 33005KT 280V360 9999 BKN010 04/02 Q1011 =
EGKK 242220Z 01007KT 9999 SCT009 BKN080 03/01 Q1011 =
EGKK 242250Z 01005KT 9999 FEW007 SCT009 03/02 Q1011 =
EGKK 242320Z 02006KT 9999 FEW007 BKN009 02/01 Q1011 =
EGKK 242350Z 36007KT 9999 BKN010 02/01 Q1011 =
EGKK 250020Z 01008KT 9999 BKN010 02/00 Q1012 =
EGKK 250050Z 04004KT 9999 FEW012 01/M01 Q1011 =
EGKK 250120Z 00000KT CAVOK M00/M01 Q1011 =
EGKK 250150Z VRB02KT CAVOK M01/M02 Q1011 =
EGKK 250220Z VRB02KT 9999 SCT032 M01/M01 Q1011 =
EGKK 250250Z 25002KT 9999 BKN030 M01/M01 Q1011 =

Finally, the 12Z 20 Feb 2004 one is one where you could envisage flying VFR below the cloud (which I'd do in a twin but not a single), but I wouldn't want to spend very long in it.

I'll reassert that I don't think that icing is likely to be an issue as often as other nasty weather. Certainly if you're stuck below the London TMA it makes a difference, with careful planning I don't think the lack of de-icing is as big a deal as is often made of it.

[Flyin'Dutch']

Icing is scary. Have had just about enough experience with it to realise I don't like it.

The situation is as bookworm describes it. There are many times that the weather is actually doable if you look beyond the first impressions you get.

De-icing is a bit like having an IR in two ways.

The first is that with the ability/equipment comes the realisation that quite often things were not as bad as you thought and you don't need it.

The second is that there will always be a next level of hindrances stopping you from being truly 'all weather' proof.

I realised that a little while ago and now just accept that there will always situations which mean you can't go. As I never 'have' to be somewhere at any cost I just live with that.

It is not just a matter of equipment level but more so the realisation that the weather one could potentially tackle with it would require more experience and currency than I will have by doing some 100-150 hours per year.

FD

[IO540]

I am sure BW does have a life but much more importantly he has the INFORMATION!!! :O

Re the JAA IR - can somebody tell me how I can work out the en route icing level and cloud tops from the officially available (or unofficially available, e.g. GFS) weather data? It is no good knowing the small details of weather physics if one cannot get the data to interpret.

Occassionally, like today, the clouds are obviously thin (1400/2200 on a flight I did today up to 7pm) but a lot of the time one cannot tell if the layer is 2000ft or 7000ft thick.

[S-Works]

The F215's on the met office site give the cloud tops.

[IO540]

Only very approximately, out by a few thousand feet a lot of the time.

[Charley]

If you don't already know about such things, and you want to make an edumicated assessment of where the cloud bases/tops may be, such a forecast can be made by reference to a Skew-T diagram, a variation on a tephigraph.

Basically the principal factors are the moisture content of the air, the environmental lapse rate (ELR) and the saturated adiabatic lapse rate (SALR).

If you would like to delve more, here are two links that you might like to look at. I will add, though, that these will still only be forecasts and guesstimates and therefore may or may not be more accurate that the stuff you see on F215s. In reality, I suspect that these techniques are largely what the met people will use to generate such forms anyway, only they have more money and sophisticated technology to help them.


Jack Harrison (http://www.itadvice.co.uk/weatherjack/tut-soundings/tut-snds-01.html) is a guy who does met forecasting for the UK's gliding fraternity. Among the many superb items on his website is a tutorial for obtaining atmospheric soundings (displayed on Skew-T's) and getting useful pieces of info from them. Page 8 of the tutorial on the link provided is where the cloud bases/tops are. A seperate tutorial explains how to get the soundings from the NOAA.
Here is an Aussie storm-chasing site (http://downunderchase.com/storminfo/stormguide/) which has more stuff on skew-T's and a bit more besides.


I was a power pilot before I was a glider pilot, but the latter has certainly taught me a lot more about met, and where to find answers to met questions. Much of which I think would be useful to certain sections of the power pilot community if they only knew about it....

Hope this helps, even if just to cure insomnia. Cheers.

* Jack's wider site can be reached through www.weatherjack.co.uk