Definition
An aircraft wheel brake in which braking force is produced by pressing curved friction shoes outward against the inside surface of a rotating cylindrical drum that is attached to the wheel. Friction between the shoes and the drum slows the wheel's rotation. Drum brakes were common on older and lighter aircraft but have largely been replaced by disc brakes, which dissipate heat more effectively.
Plain English
A type of brake where shoes push outward against the inside of a spinning drum on the wheel to slow it down. Older design, mostly replaced by disc brakes on modern aircraft.
Context Anchor
Seen in aircraft brake system descriptions, maintenance manuals, and inspections of older or smaller aircraft wheel brakes.
Derivation
Named for the drum-shaped rotating component. The word 'drum' here describes the shape -- a hollow cylinder, like a musical drum -- that the brake shoes press against from the inside.
Why Pilots Care
Provides reliable stopping power after landing, directly affecting runway performance and safety margins.
Analogy
Think of holding your hands inside a spinning metal bowl and pressing outward to slow it down. In a drum brake, the brake shoes press outward against the inside of the drum in a similar way.
Intuition Check
A drum brake is not just any round-looking brake. The key point is that the friction pieces press against the inside of a rotating drum.
Example Sentence 1
The older trainer was fitted with drum brakes, so the instructor cautioned against repeated hard braking on the long taxi back.
Example Sentence 2
Smooth application of the drum brakes prevented skidding on the short, wet runway.