Controller for an aircraft system

A method of operating a controller of an aircraft system of an aircraft, the aircraft system comprising an actuation system and a first energy supply which supplies power to the actuation system, wherein the actuation system includes a first actuator and the method comprises:

• when the aircraft system is configured in a first configuration in which the first actuator is coupled to the first energy supply, determining that there is a loss of energy supplied to the first actuator from the first energy supply;
• determining a current performance of the actuation system achievable if the aircraft system is configured in the first configuration, wherein the determination of the current performance is after the determination of the loss of the energy supplied to the first actuator;
• determining, a predicted performance of the actuation system achievable by the aircraft system if configured in an alternative configuration in which the first actuator is uncoupled from the first energy supply, wherein the determination of the predicted performance is determined while the aircraft system is in the first configuration;
• comparing the current performance to the predicted performance, wherein the comparison is performed while the aircraft system is in the first configuration;
• determining, based on the comparison of the current performance to the predicted performance, a change in performance of the actuation system achievable by reconfiguring the aircraft system from the first configuration to the alternative configuration, and
• causing reconfiguration of the aircraft system from the first configuration to the alternative configuration when the change in performance of the actuation system is a gain in performance over the current performance.

A controller for an aircraft braking system of an aircraft, the aircraft braking system comprising a brake actuation system including a brake actuator and an energy supply system including a first energy supply which supplies power to the brake actuation system, the controller configured to:

• when the aircraft braking system is configured in a first configuration, in which the brake actuator is coupled to the first energy supply, determine that there is a loss of energy supplied to the brake actuator from the first energy supply;
• after the determining of the loss of energy, determining a current performance of the brake actuation system achievable if the aircraft system remains in the first configuration;
• determine predicted performances achievable by the brake actuation system if configured in each of a plurality of alternative configurations, wherein the determination of the predicted performances is after the determination of the loss of the energy supplied to the brake actuator and while the aircraft braking system is in the first configuration;
• comparing the current performance to each of the predicted performances, wherein the comparing the current performance to each of the predicted performances occurs while the aircraft braking system is in the first configuration;
• using the comparisons of the current performance to each of the predicted performances to select one of the alternative configurations which would result in a gain in performance from the current performance;
• and
• cause reconfiguration of the aircraft braking system from the first configuration to the alternative configuration selected by the controller.