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Star Alliance created the topic: Icing in thick altostratus at -2°C
Hi all, a quick question regarding icing:
You are cruising in thick altostratus cloud where the outside air temperature is -2°C. What type of icing is most likely to occur?
C.both rime and clear
I saw this question from previous post. I would go for C, because the word ”thick ” means strong vertical development which can form large droplet. But someone says the answer A）rime ice only is correct.
Can’t find a solid answer. Can anyone help?
S70BlackHawk replied the topic: Icing in thick altostratus at -2°C
It’s B clear ice for two reasons. 1st is the cloud type. As you mention the “thick” vertical development and thus larger water droplets. 2nd is the temp is only -2deg. So not as cold for when the large droplets impact the aircraft.
Combination of these two factors lead to a large, not so cold 0 to -10deg, droplet hitting the leading edge and then sliding back and freezing. Thus causing clear ice. Rime is formed at much colder temps -10-20deg and smaller droplets in stratiform clouds because they freeze on impact. Causing clumps of ice with air trapped inside as well. Hope this helps.