Abstract: The brake valve control system for an aircraft wheel bracking system includes primary and backup brake valve control subsystems and isolates and switches between subsystems. Certain portions of the entire braking system are shared, and those portions which are not shared are isolated but interconnected for switching from a primary brake control mode to a backup subsystem upon failure of the primary subsystem. A unique metering spool valve, and the linking of metering spool valves and servocontrol valves with either a tandem selector valve or interlinked primary and secondary selector valves allows for significant reduction in weight and complexity for the backup or override system.

Abstract: A hydraulic braking system including hydraulically operated brakes and a hydraulic master cylinder for controlling the operation of the brakes. A conversion assembly is used for providing power-assisted braking in the system. The conversion assembly is capable of operating in a manual mode to couple master cylinder pressure to the hydraulic brakes or in a power-assisted mode to supply an amplified hydraulic braking pressure to the hydraulic brakes in response to the master cylinder pressure. The conversion assembly is also operable to provide deceleration control during braking to prevent skidding of the wheels being braked.

Abstract: A hydraulic braking system including hydraulically operated brakes and a hydraulic relay valve for controlling the operation of the brakes in response to a mechanical input. The relay valve includes a metering valve having a medial and distal pair of axially-aligned lands with different diameters, defining an annular chamber between each medial and distal land. A modulator is included to provide a skid control capability. The modulator is hydraulically connected to one of the annular chambers, with system hydraulic pressure being provided to the other. This enables the modulator to vary the position of the metering valve as needed to prevent skidding of the wheels being braked.

Abstract: A hydraulic braking system including hydraulically operated brakes and a hydraulic master cylinder for controlling the operation of the brakes. A conversion assembly is used for providing power-assisted braking in the system. The conversion assembly is capable of operating in a manual mode to couple master cylinder pressure to the hydraulic brakes or in a power-assisted mode to supply an amplified hydraulic braking pressure to the hydraulic brakes in response to the master cylinder pressure. The conversion assembly is also operable to provide deceleration control during braking to prevent skidding of the wheels being braked.