Definition
A mechanical device that holds the airplane's wheel brakes in the applied position without the pilot having to keep pressure on the rudder pedal toe brakes. It is set by pressing the brakes and then engaging a lever, knob, or handle that locks hydraulic pressure (or mechanical linkage) on the brake system until released.
Plain English
A control that keeps the brakes pressed for you so the airplane stays put while you take your feet off the pedals.
Context Anchor
Seen during preflight, engine start, before-takeoff checks, and any time the airplane must stay still on the ground.
Why Pilots Care
It prevents the airplane from rolling unexpectedly during ground operations or when left unattended.
Intuition Check
Do not assume the parking brake makes the airplane completely secure in all conditions. It only holds the wheel brakes, and the pilot must still confirm it is set or released at the correct time.
Example Sentence 1
Before the run-up, the pilot pressed firmly on the toe brakes and set the parking brake.
Example Sentence 2
During the before-takeoff check the pilot confirmed the parking brake was holding the airplane firmly in place.