Definition
A small, hard friction block made of a special composite material, fitted into the brake assembly of an aircraft wheel. When the brakes are applied, hydraulic pressure forces the pucks against a rotating disc attached to the wheel, and the friction slows the aircraft.
Plain English
A small puck-shaped friction pad inside the wheel brake. It gets squeezed against a spinning disc to slow the wheel down.
Context Anchor
Encountered during aircraft maintenance, brake inspections, and preflight discussions about wheel and brake condition.
Derivation
Called a 'puck' because of its shape -- a small, round, flat disc, much like a hockey puck. The word 'puck' came into English in the 1800s for a small disc used in games.
Why Pilots Care
Worn or glazed brake pucks reduce stopping power and can cause longer landing rolls or brake fade, directly affecting safety margins on every landing.
Analogy
A brake puck works much like the rubbing part of a bicycle brake pad: it is meant to wear slowly as it presses against a moving wheel part to slow it down.
Intuition Check
A brake puck is not a separate brake control or a fluid part. It is the physical friction piece that gets squeezed against the brake disc.
Example Sentence 1
During the wheel inspection the mechanic found that the brake pucks were worn down to the minimum allowable thickness and replaced them.
Example Sentence 2
After a hard landing the pilot noticed reduced brake effectiveness caused by overheated and glazed brake pucks.