Definition
Inflatable rubber strips bonded to the leading edges of an aircraft's wings, stabilizers, and sometimes other surfaces, used to remove ice that has formed during flight. Compressed air is cycled through tubes inside the boot, causing it to expand and contract. This flexing cracks the accumulated ice, which is then carried away by the airstream.
Plain English
Rubber covers on the front edges of the wings and tail that puff up with air to crack off ice that has built up in flight, so the wind can blow it away.
Context Anchor
Seen in aircraft systems, icing procedures, preflight inspections, and operations in visible moisture near or below freezing temperatures.
Derivation
Called 'boots' because they fit over the leading edge the way a boot fits over a foot — a snug protective covering. The term has been used in aviation since the 1930s when B.F. Goodrich first developed them.
Why Pilots Care
Ice on wings destroys lift and can cause loss of control; deicer boots restore clean airflow and maintain safe flight.
Analogy
Think of bending a thin sheet of ice on a rubber mat. When the rubber flexes, the ice cracks and breaks away.
Intuition Check
Deicer boots are not shoes, and they do not keep ice from forming forever. They are inflatable coverings that help break off ice that has already built up.
Example Sentence 1
After picking up a quarter-inch of rime ice in the climb, the pilot activated the deicer boots and watched the ice crack and shed from the wing.
Example Sentence 2
During the preflight walk-around the instructor pointed out a small tear in one of the deicer boots that needed repair before the next flight.