Definition
A hydraulic component installed in a brake system that reduces the pressure delivered to the brake while increasing the volume of fluid sent to it. It allows a high-pressure, low-volume hydraulic system to operate brakes that need lower pressure but a larger amount of fluid for proper actuation.
Plain English
A device in the brake line that takes high-pressure hydraulic fluid from the airplane's main system, lowers the pressure, and sends a larger amount of fluid to the brake so it works correctly.
Context Anchor
Seen in aircraft brake system descriptions, especially in maintenance or systems training for airplanes with hydraulic brakes.
Derivation
Formed from 'de-' (meaning 'reverse' or 'reduce') and 'booster' (a device that increases something). A booster raises pressure; a debooster does the opposite -- it lowers pressure while increasing fluid volume.
Why Pilots Care
Brakes designed for lower pressures would be damaged or grab too aggressively if connected directly to a high-pressure hydraulic system. The debooster makes the two compatible and gives smoother, more controllable braking.
Intuition Check
Do not read “debooster” as meaning the brakes are being made weak. It means the system is changing high hydraulic pressure into a pressure and fluid amount the wheel brakes can use properly.
Example Sentence 1
When the brake pedal is pressed, hydraulic fluid passes through the debooster before reaching the brake assembly.
Example Sentence 2
During landing the debooster supplied steady pressure to the brakes without causing the wheels to lock.