icing/freezing
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Sorry I don't have any specific references yet (I'm sure others will follow) but here I go:
Freezing conditions are when the air temperature is approaching, at or below 0 degrees Celsius, that is, the ambient temperature is approaching, at or below the freezing point of water.
Icing conditions are when the atmospheric conditions support icing. A common GA way of putting this for airframe icing is when operating in freezing conditions with visible moisture present (cloud or precipitation).
Again, these are not bulletproof definitions, but my interpretation. I hope this gives you a good start.
Freezing conditions are when the air temperature is approaching, at or below 0 degrees Celsius, that is, the ambient temperature is approaching, at or below the freezing point of water.
Icing conditions are when the atmospheric conditions support icing. A common GA way of putting this for airframe icing is when operating in freezing conditions with visible moisture present (cloud or precipitation).
Again, these are not bulletproof definitions, but my interpretation. I hope this gives you a good start.
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I'd agree with the above - "icing conditions" are when ice can form, freezing conditions are when water (typically) can freeze. I doubt there will be any single definitive definition, since things like the indicated temperature will differ from aircraft to aircraft (depending if the system indicates TAT or SAT, for one example) I know of aircraft where there are different definitions for icing conditions in flight and on the ground, and where the icing conditions for the engine are different again.
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icing/freezing
If the temperature is below freezing and you are in clear air, there is no icing threat. For icing to be a threat, there has to be visible moisture in the atmosphere in the form of cloud, mist, FZFG FZRA FZDZ etc or SLD. If these conditions exist, then there is an icing threat and the severity of that threat is based on a number of different factors. Also saturated air temperature will determine what sort of ice will be encountered. In aviation terms, there are really two types that you will hear mentioned. These being Rime ice which will occur at colder temperatures and Clear ice which will occur closer to the freezing level. Mixed ice is a combination of the two and you will also see this in icing forecasts or pilot reports. Ice will not normally build or accrete on an aircraft outside the SAT range of +2 through -20c but the only physically limiting factor is -40c.
Hope this helps,
Hope this helps,
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Hassan,
I concur with the others. In colloquial terms "freezing conditions" means temperatures are at or below the freezing point, and "icing conditions" means water will actually turn into ice. However, like Mad (Flt) Scientist has already pointed out, there is probably no legal definition. But maybe the two following references might help you.
For the MATER code WMO Manual on Codes, Volume I.1, Part A, Section A, Subsection a, Regulation 15.8.9 says
For SIGMET and AIRMET ICAO Annex 3, Appendix 6, 4.2.7 applies:
I concur with the others. In colloquial terms "freezing conditions" means temperatures are at or below the freezing point, and "icing conditions" means water will actually turn into ice. However, like Mad (Flt) Scientist has already pointed out, there is probably no legal definition. But maybe the two following references might help you.
For the MATER code WMO Manual on Codes, Volume I.1, Part A, Section A, Subsection a, Regulation 15.8.9 says
the qualifier FZ shall be used only to indicate supercooled water droplets or supercooled precipitation.
For SIGMET and AIRMET ICAO Annex 3, Appendix 6, 4.2.7 applies:
Recommendation.- Severe and moderate icing (ICE) sholud refer to icing in other than convective clouds. Freezing rain (FZRA) should refer to severe icing conditions caused by freezing rain.
