Definition
A type of aircraft wheel brake in which braking action is produced by clamping stationary friction pads against one or more rotating discs attached to the wheel. When hydraulic pressure is applied, the pads squeeze the disc, and the friction slows the wheel.
Plain English
A brake that slows the wheel by squeezing flat pads against a spinning metal disc that turns with the wheel.
Context Anchor
Seen in landing gear and brake system discussions, especially during taxi, landing rollout, preflight checks, and maintenance.
Derivation
From Latin discus, meaning a flat round plate. The name describes the shape of the rotating component the pads grip.
Why Pilots Care
Provides reliable, fade-resistant stopping power after landing and helps prevent runway overruns.
Analogy
It works much like many bicycle or car disc brakes: a spinning disc turns with the wheel, and pads squeeze the disc to slow it down.
Intuition Check
Do not confuse a disc brake with a brake pedal or parking brake control. The disc brake is the brake assembly at the wheel that actually creates the slowing force.
Example Sentence 1
During preflight, the pilot checked the disc brakes for adequate pad thickness and looked for any hydraulic fluid leaks around the calipers.
Example Sentence 2
During the walk-around the student pilot checked the thickness of the pads on each disc brake.