Definition
Rubber-like protective coverings bonded to the leading edges of wings and stabilizers that, when inflated by engine bleed air or a dedicated pump, expand and contract to crack and shed accumulated ice. Once the ice breaks, the airstream carries it away, and the boots deflate flush against the surface for normal flight.
Plain English
Rubber strips along the front of the wings and tail that puff up like balloons to break ice off the airplane, then flatten back down again.
Context Anchor
Seen in aircraft ice-protection system descriptions, cockpit checklists, and winter flying procedures for aircraft approved for flight in icing conditions.
Derivation
The word 'boot' is used here in the older sense of a protective covering (like a rubber boot over a shoe). The boot 'inflates' because it's a hollow rubber sleeve filled with pressurized air to change its shape.
Why Pilots Care
Ice accumulation destroys lift and increases drag; these boots restore clean airflow so the airplane can continue to fly safely.
Analogy
Think of a thin rubber cover under a brittle layer of ice. When the cover puffs outward, the ice cracks and can be swept away by the moving air.
Intuition Check
Do not read “boots” as footwear, and do not read “deicing” as preventing ice. Inflatable deicing boots are aircraft surface covers that remove ice after it has formed.
Example Sentence 1
After picking up about a quarter inch of ice on the leading edges, the captain activated the deicing boots and watched the ice crack and peel away.
Example Sentence 2
During the preflight inspection the pilot verified that the inflatable deicing boots were free of cracks and ready to operate.