Plain English Meaning

Rubber strips along the front edges of the wings and tail that puff up like a balloon to crack ice off, then flatten back down so the wing flies normally again.

Full Definition

Inflatable rubber sleeves bonded to the leading edges of wings and tail surfaces that expand and contract pneumatically to break off ice that has already formed. When activated, engine-driven pneumatic pressure inflates the boots, cracking the accumulated ice so that airflow carries it away; the boots then deflate and return flush with the airfoil shape.

Context Anchor

Seen in aircraft ice-protection discussions, especially for airplanes certified to fly in icing conditions.