Definition
Solid carbon dioxide (CO2) at approximately -109.3°F (-78.5°C) that sublimates directly from solid to gas at atmospheric pressure without passing through a liquid phase. In aviation maintenance, it is used as an extreme cold source for shrink-fitting metal parts and for chilling components during certain repair and assembly procedures.
Plain English
Frozen carbon dioxide. It is much colder than regular ice and turns straight into gas instead of melting into water. Mechanics sometimes use it to shrink a metal part so it slips into place, then warms up and locks in tight.
Context Anchor
Seen in aircraft maintenance shops, shipping, and storage when parts or materials need to be kept very cold.
Derivation
Called 'dry' because it leaves no liquid behind when it changes state — unlike water ice, which melts into a puddle. The 'ice' part simply refers to its solid, frozen form.
Why Pilots Care
As it warms it releases large amounts of carbon dioxide gas that can displace oxygen inside aircraft compartments.
Grounding Statement
If dry ice is left out in the open, it slowly disappears because it is turning into gas.
Intuition Check
Dry ice is not frozen water. It is frozen carbon dioxide, and it does not melt into liquid water.
Example Sentence 1
The technician packed dry ice around the bushing to shrink it before pressing it into the wheel hub.
Example Sentence 2
After unloading dry ice from the cargo hold, the crew opened all vents to clear any remaining gas.