Plain English Meaning

The two small pads inside the brake unit that squeeze against the spinning brake disc to slow the wheel down.

Full Definition

The friction-material blocks held inside a brake caliper that press against the rotating brake disc to slow or stop a wheel. When the pilot applies the brakes, hydraulic pressure forces the caliper pads against the disc, and the resulting friction converts the wheel's motion into heat.

Context Anchor

Seen in landing gear and brake system descriptions, maintenance discussions, and inspections of aircraft wheel brakes.

Derivation

A caliper is a device with two arms or jaws that grip something from opposite sides. In a disc brake, the caliper straddles the disc and squeezes the pads against it from sides — hence 'caliper pads.'