Peter wrote:
The TKS won’t last long enough no matter which way you slice that one
You won’t “gamble” with there being little or no icing in the clouds? If it comes to the worst, you would have enough TKS fluid to divert.
That is all that airliners say
Yes but they will also tell you for how many miles. Transparency goes a long way.
When I returned from EDNY after the show it was clear that my filed flight level wouldn’t be high enough to get out of the clouds. I told ATC that I’d need to continue the climb ‘till I got clear. I also mentioned this was to make sure I wouldn’t ice up. German ATC was superb and cleared me for everything I asked. Sometimes they needed a moment to make a coordination but I anticipated this. They got some nice PIREPs back in return.
I would be very surprised any atco in Europe wouldn’t understand icing. It is very well and multiple times explained during training.
Peter wrote:
I think the key point is to always use ICAO phraseology, which means keeping it very simple: Nxxxx request 20 degrees left to avoid.
Avoid what? 99% of their „customers“ avoid CBs only. Include „due to icing conditions“ and every ATCO will help you out and understand. In their „mental model“ a plane cruising at FL200 isn’t a small SEP but a plane of similar capability to an airbus… just my 0.2 worth.
Peter wrote:
Yes you should, because you are entitled to carry out hazardous wx avoidance.
Hmm.
NCO.OP.170 Ice and other contaminants — flight procedures
(a) The pilot-in-command shall only commence a flight or intentionally fly into expected or actual icing conditions if the aircraft is certified and equipped to cope with such conditions as referred to in 2.a.5 of Annex IV to Regulation (EC) No 216/2008
While on the one hand, it’s appropriate to expect a certain amount of flexibility from ATC, as one gets with convective weather, I would suggest that you not expect ATC to rearrange the entire traffic flow of W Europe to give you the routing you require to avoid icing at your planned levels.
Peter wrote:
which looks like ~FL200 tops. The TKS won’t last long enough no matter which way you slice that one
Assuming that’s today weather, the DWD icing forecast shows only light icing at 140 and 180. I’d be disappointed if you can’t manage a couple of hours in that with TKS.
My feeling if you want something just say it in plan English with keyword “urgent”?
I once asked Bristol ATC if I can avoid flying through localized patches of rain while on direct IFR crossing clearance to Cardiff
First they were puzzled but I explained it is last minute urgent request due to a nervous passenger, they just suggested cancel IFR, 90degres left turn, urgent descent 2400ft, own navigation to exit CAS and remain VMC, turns out to be a long detour, so I think I can’t have it all while flying IFR even with tactical weather radar: flying that close to weather without getting in? or just have plan B?
I think it will probably help to tell them early even if that means a sub-optiomal clearance and have enough margins…
Peter wrote:
I think the key point is to always use ICAO phraseology, which means keeping it very simple: Nxxxx request 20 degrees left to avoid.
I am not sure 20 left to avoid actually is ICAO phraseology. It seems more a common shorthand to explain a diversion needed due to convective weather in front.
the DWD icing forecast shows only light icing at 140 and 180.
The above image was captured at the time I posted the IR image above.
Moderate ice will bring down a GA plane in minutes, to tens of minutes, if there is no ice protection. The red dots are “severe” icing.
Now, I don’t believe icing forecasts are worth a damn most of the time (beyond looking at the MSLP) but you mentioned DWD so I posted it 
I’d be disappointed if you can’t manage a couple of hours in that with TKS.
A couple of hours is all you do get
Not taking this too far off topic, that is why I would be really pro-active on IMC avoidance in icing conditions.
While on the one hand, it’s appropriate to expect a certain amount of flexibility from ATC, as one gets with convective weather, I would suggest that you not expect ATC to rearrange the entire traffic flow of W Europe to give you the routing you require to avoid icing at your planned levels.
I agree but that is hardly the proposition! Especially as – terminal areas excepted – GA flies in airspace almost totally devoid of traffic.
You won’t “gamble” with there being little or no icing in the clouds? If it comes to the worst, you would have enough TKS fluid to divert.
I plan flights to land at the destination with a high degree of probability The Adriatic aside, most diverts are to places which are total sh*tholes in which one really doesn’t want to end up in, especially with passengers.
Here are the forecasts for 1200. at the levels I indicated:
Icing layers are not usually very thick.
Your approach seems to be that you must maintain VMC at all times when above the freezing level. I don’t think you should be surprised when ATC has an issue with that.
Or (to come back to the OP) if you must maintain VMC at all times when embedded CBs are forecast.
Your approach seems to be that you must maintain VMC at all times when above the freezing level.
Enroute, generally, that is how I plan flights. Normally this is not an issue, in a plane which can do FL180-200. The despatch rate on a given day is probably 90% if you have full TKS.
In many situations a lot of ice is pretty well assured even if stuff like the DWD chart is clean. If e.g. you sit say 300ft below the top of a stratus layer at -5C, you will collect ice at quite a rate, prob90+.
I don’t think you should be surprised when ATC has an issue with that.
Why should they have an issue with it? The airspace below FL250 is mostly empty, away from terminal areas.
I normally climb up to be above the “organised” IMC and sit there. I’ve never had any problem doing that. Very rarely, as previously reported, an ATCO doesn’t like to approve a left/right to avoid. The really “aggressively defended” cases were French military airspace (“the military commander is very unhappy” when I was avoiding CBs while flying at FL190) but elsewhere it tends to be more “frivolous” stuff like that Austrian one I posted above where another pilot told her (in German so I could not hear it) that I was lying about the wx.
Or (to come back to the OP) if you must maintain VMC at all times when embedded CBs are forecast.
Definitely.
I am not sure 20 left to avoid actually is ICAO phraseology
I wonder what would be?
