Definition
A wheel brake design in which the rotation of the wheel itself is used to assist in applying braking force, multiplying the pilot's pedal input through the friction between the brake shoe or lining and the rotating drum or disc.
Plain English
A brake that uses the spinning of the wheel to help squeeze itself tighter, so a small push on the pedal produces a much larger braking force.
Context Anchor
Seen in aircraft maintenance discussions of older drum-type wheel brake systems.
Derivation
The word 'servo' comes from the Latin servus, meaning 'servant' or 'helper.' A servo brake is one where the wheel's own motion 'serves' the pilot by amplifying the force applied at the pedal.
Why Pilots Care
Delivers strong deceleration with lighter pedal pressure, shortening landing rolls and reducing pilot workload.
Intuition Check
Do not read “servo” here as an electric motor or autopilot part. In “servo brake,” it means the brake action is assisted by the wheel’s own motion.
Example Sentence 1
The technician inspected the servo brake assembly to verify the shoes were seating correctly against the drum.
Example Sentence 2
During the annual inspection the mechanic verified that the servo brake linkage still allowed the self-energizing action to function.