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European / EASA definition of "known icing"

From here

To add to that, in Europe the legal stuff is the following:

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.
(b) If icing exceeds the intensity of icing for which the aircraft is certified or if an aircraft not certified for flight in known icing conditions encounters icing, the pilot-in-command shall exit the icing conditions without delay, by a change of level and/or route, and if necessary by declaring an emergency to ATC.

GM1 NCO.OP.170(b) Ice and other contaminants — flight procedures
KNOWN ICING CONDITIONS
Known icing conditions are conditions where actual ice is observed visually to be on the aircraft by the pilot or identified by on-board sensors.

Personally I consider any visible moisture at around 0° as expected icing conditions that I avoid. Of course that’s my personal minimum, experienced IFR pilots are able to make more accurate judgements. Unfortunately I have more knowledge of air law than real world experience. :)

Thanks for your thread! I think I can learn a lot about decision making skills from it.

Last Edited by ArcticChiller at 30 Jan 07:23

I extracted the above post from that linked thread because it is highly valuable.

I find an inconsistency here:

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.

Known icing conditions are conditions where actual ice is observed visually to be on the aircraft by the pilot or identified by on-board sensors.

Condition (2) is not likely to be observed prior to the start of a flight

I googled for that reg, and " 2.a.5 of Annex IV to Regulation (EC) No 216/2008. " says

What does this actually mean in practice?

No flight into IMC below 0C? The FAA experimented with such a definition many years ago and abandoned it. @bookworm might know the background to this, although he may not be around anymore?

Administrator
Shoreham EGKA, United Kingdom

Peter wrote:

No flight into IMC below 0C? The FAA experimented with such a definition many years ago and abandoned it

Something like FIKI = flight cannot be done without cloths & heater & artificial horizon in open cockpits may work?

ESSEX, United Kingdom

@bookworm might know the background to this, although he may not be around anymore?

The reports of my death have been greatly exaggerated

I don’t see the inconsistency you do. Condition 1 does not mention “ known icing conditions”. It’s only mentioned in para (b).

2.a.5 is no more. The equivalent in the new BR now says

(e) appropriate mitigation measures or contingency plans must be in place to deal with potentially hazardous atmospheric conditions expected to be encountered in flight;

How do you think NOO.OP.170(a) should be revised?

So even if icing is forecast on a sig chart you could depart in a non fiki plane and if you do not encounter icing it was all legal…?

The airlines that I know of use 10° C and visible moisture (mist, rain, snow, deposits on taxiway etc..) as “icing conditions”. Is that definition found in any legal text (apart from the airlines’ operations manuals).

has a Beagle...
LOWG Graz Austria

No, according to AMC1 CAT.OP.MPA.255 procedures for flight into known icing in commercial transport are established in the Operations Manual and based on the specific aircraft’s manual. I would suppose that the 10°C might be defined by an airline due to the high climb rates their planes achieve. A jet requires other procedures than Part-NCO aircraft
Here’s a link to the Air Ops Regulation: https://www.easa.europa.eu/document-library/general-publications/easy-access-rules-air-operations

I think the rule in Part-NCO is clear enough. If you expect icing, don’t fly into these conditions. This expectation of icing is very much dependent on the pilot’s assessment. As I said in the previous post: Due to my low experience, I would expect icing in any visible moisture at around 0°C (actually even up to 3 or 4°) and colder. Meanwhile, a highly experienced IFR pilot might not expect icing in the same weather, say because it is highly unlikely in the given conditions (e.g. way too cold temperatures or other factors).

I figured it out…

Edit: lol …if I translate back to German it reads: “Fliegen Sie nicht, wenn Sie auf diesem Flug nach Ihrem Urteil Sahnehäubchen erwarten.” (no kidding this time)

Last Edited by ArcticChiller at 30 Jan 22:30

This is pure gold. Saved and put in to circulation! ;)

has a Beagle...
LOWG Graz Austria

Snoopy wrote:

The airlines that I know of use 10° C and visible moisture (mist, rain, snow, deposits on taxiway etc..) as “icing conditions”. Is that definition found in any legal text (apart from the airlines’ operations manuals).

That is typically the aircraft manufacturers. The CJ is the same. Engine antiice comes on in visible moisture at +10C and below.

EGTK Oxford

JasonC wrote:

the aircraft manufacturers

Ahhh yes of course, hadn’t thought of that.

has a Beagle...
LOWG Graz Austria

bookworm wrote:

2.a.5 is no more. The equivalent in the new BR now says

(e) appropriate mitigation measures or contingency plans must be in place to deal with potentially hazardous atmospheric conditions expected to be encountered in flight;

How do you think NOO.OP.170(a) should be revised?

One solution is to delete it completely, since BR Annex V section 2.(e) already says it all. If we really must have more precise rules, I’d like to remove the reference to certification for icing, and focusing on the aircraft’s actual capabilities, not its certification. Something like:

(a) The pilot-in-command shall only commence a flight or intentionally fly into expected or actual icing conditions having considered the aircraft’s equipment and ability to cope with these conditions, and having taken appropriate mitigation measures or made contingency plans in line with the aircraft’s ability;

(b) If icing exceeds the intensity of icing which the aircraft is able to cope with, the pilot-in-command shall exit the icing conditions without delay, by a change of level and/or route, and if necessary by declaring an emergency to ATC.

ELLX
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