Brake control system for aircraft

A portion of an aircraft hydraulic braking system comprising:

• a first brake and a second brake each hydraulically operated;
• a brake system hydraulic supply pressure;
• a brake system return pressure;
• an electronic brake system controller, the electronic brake system controller providing a signal to a valve to open or to close;
• a first brake control valve, responsive to the electronic brake system controller to apply the first brake, and a second brake control valve, responsive to the electronic brake system controller to apply the second brake;
• a first shutoff valve and a second shutoff valve, each hydraulically connected to the brake system hydraulic supply pressure and the brake system return pressure, the first shutoff valve providing a first output pressure to the first brake control valve in response to a first signal from the electronic brake system controller to open and apply the brake system hydraulic supply pressure. and alternatively providing the brake system return pressure in response to the first signal from the electronic brake system controller to close;
• and the second shutoff valve providing a second output pressure to the second brake control valve in response to a second signal from the electronic brake system controller to close and apply the brake system hydraulic supply pressure when commanded to open and alternatively providing the brake system return pressure in response to the second signal from the electronic brake system controller to close;
• a first paired wheel shuttle interposed between the first brake control valve and the first brake and hydraulically connected to the first brake control valve, the first brake, the second brake, and having a first larger area sensing port hydraulically connected to the first shutoff valve, and a first smaller area sensing port hydraulically connected to the second shutoff valve;
• a second paired wheel shuttle interposed between the second brake control valve and the second brake and hydraulically connected to the second brake control valve, the second brake, the first brake, and having a second larger area sensing port hydraulically connected to the second shutoff valve, and a second smaller area sensing port hydraulically connected to the first shutoff valve;
• when the first shutoff valve is open to port brake hydraulic system supply pressure to the first larger area sensing port, the first paired wheel shuttle hydraulically connects the first brake control valve to the first brake and blocks its connection to the second brake;
• but if, in response to a first brake control fault having been detected, the electronic brake system controller provides the first signal to close to the first shutoff valve, the brake system return pressure acting on the first larger area sensing port allows the brake system hydraulic supply pressure from the second shutoff valve acting on the first smaller area sensing port to actuate the first paired wheel shuttle to block its connection to the first brake control valve and hydraulically connect the first brake to the second brake instead, thereby enabling the second brake control valve to control both the first brake and the second brake, the electronic brake system controller further providing paired wheel antiskid control to both the first brake and the second brake;
• and similarly, in response to a second brake control fault having been detected instead of the first brake control fault, the second paired wheel shuttle is operative to enable the first brake control valve to control both the first brake and the second brake, further providing paired wheel antiskid control to both the first brake and the second brake.

A hydraulic braking system for an aircraft comprising:

• an aircraft hydraulic supply providing a hydraulic pressure;
• an aircraft hydraulic return;
• a plurality of brakes, a brake being hydraulically actuated;
• controls comprising a plurality of valves and a plurality of sensors to control and monitor the hydraulic pressure to said plurality of brakes;
• said plurality of valves, the plurality of sensors, and the plurality of brakes being partitioned into autonomous groups such that they hydraulically share only the aircraft hydraulic supply and the aircraft hydraulic return;
• each autonomous group being housed in a pod comprising a single hydraulic module;
• and an accumulator connected to and dedicated to each pod, the accumulator providing a limited source of stored energy to power the pod if the aircraft hydraulic supply is lost.