SESKStuff Everyone Should Know
SESK: Stuff Everyone Should Know · sesk.info/ifr-rime-ice

Which description matches rime ice?

Rime ice is rough, milky and opaque.

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  1. Rough, milky, opaque ice from tiny supercooled droplets ✔
  2. Clear, smooth ice from large, slow-freezing droplets
  3. Frost that forms on an airplane parked overnight

Why: Small supercooled droplets freeze almost instantly when they strike the airplane. The rapid freezing traps air, so the ice is porous, brittle and milky. Clear ice is smoother and favors warmer temperatures.

Huh, didn't know that: Rime is the most frequently reported type of icing.

The dad joke
Why didn't the icicle go to school? Because he's too cool for school.
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References

Answer: Rough, milky, opaque ice from tiny supercooled droplets. Small supercooled droplets freeze almost instantly when they strike the airplane. The rapid freezing traps air, so the ice is porous, brittle and milky. Clear ice is smoother and favors warmer temperatures.

  1. FAA Aviation Weather Handbook (FAA-H-8083-28B) www.faa.gov/sites/faa.gov/files/FAA-H-8083-28B.pdf
    Rime ice is rough, milky, and opaque ice formed by the instantaneous freezing of small, supercooled water droplets
    Checked 2026-10-11.
  2. FAA Aviation Weather Handbook (FAA-H-8083-28B) www.faa.gov/sites/faa.gov/files/FAA-H-8083-28B.pdf
    It is the most frequently reported icing type.
    Checked 2026-10-11.
  3. FAA Aviation Weather Handbook (FAA-H-8083-28B) www.faa.gov/sites/faa.gov/files/FAA-H-8083-28B.pdf
    clear ice when the temperature is warmer than -10°C
    Checked 2026-10-11.

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FlyingIce blocks a pitot tube's ram opening and its drain hole. What does the airspeed indicator do in a climb?FlyingStatic ports ice over at 5,000 feet and you climb to 7,000. What does the altimeter show?FlyingYou see ice pellets at the surface. What do they tell you about conditions aloft?

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