Abstract: Aircraft and methods and systems for controlling performance of an aircraft. The methods and systems allow the aircraft to meet a performance requirement using a set of aircraft flight data and actuators connected to control surfaces. Performance data for primary and secondary actuators are obtained to select between a primary control law for controlling the primary control surface, a secondary control law for controlling the secondary control surface, and a blended control law that controls the primary and secondary control surfaces together. If the primary control surface cannot meet the aircraft performance requirement using the primary control law, the blended control law is implemented if the primary and secondary control surfaces can be used together to meet the performance requirement; otherwise the secondary control surface is used, using the secondary control law, to meet the aircraft performance requirement.

Abstract: A reliably redundant PCU for an aircraft. The PCU includes an override mechanism coupled to the aircraft's control path and a first control member coupled to the override mechanism whereby the override mechanism attempts to transmit a command from the command path to the first control member. The unit also includes a second control member coupled to the control path whereby the command path transmits the command to the second control member. Additionally, the PCU includes two actuator members coupled to the control members whereby the actuator members attempt to move in response to the command. If the first control member resists moving the override mechanism allows the second control member to actuate the rudder. The PCU also includes a common actuator coupled to the actuator members and the control surface, whereby the actuator moves the control surface. Moreover, a unitary housing contains the first and the second actuator members.