Disclosed is a controller (200, 300, 400, 610) for an aircraft
system of an aircraft (10), the aircraft
system comprising a first
actuator (114A) and a first
energy supply (111A), the controller (200, 300, 400, 610) configured to, when the aircraft
system is configured in a first configuration, in which the first
actuator (114A) is coupled to the first
energy supply (111A), determine that there is a loss of energy supplied to the first
actuator from the first
energy supply. The controller (200, 300, 400, 610) is configured to determine a change in performance achievable by reconfiguring the aircraft system from the first configuration to an alternative configuration, in which the first actuator (114A) is uncoupled from the first energy supply, and cause reconfiguration of the aircraft system from the first configuration to the alternative configuration, in the event that the change in performance determined by the controller (200, 300, 400, 610) is a
gain in performance.