Rotorcraft with a flight control system for improving rotorcraft control upon occurrence of an in-flight shutdown in an asymmetric flight regime mode

A flight control system for a rotorcraft that comprises at least one main rotor with at least one main rotor actuator for adapting main rotor control dependent on a current flight condition of the rotorcraft, wherein main rotor actuator stroke of the at least one main rotor actuator is adjusted via series actuator stroke of at least one series actuator arranged upstream of the at least one main rotor actuator, wherein the at least one series actuator is coupled to a control lever that is connected to at least one parallel actuator, and wherein at least one first engine and at least one second engine are provided for powering the at least one main rotor;

• the flight control system being configured for controlling flight operation of the rotorcraft at least in an All Engines Operative mode, in which the at least one first engine and the at least one second engine are powering the at least one main rotor, or in an asymmetric flight regime mode, in which only the at least one first engine is powering the at least one main rotor, and comprising:
• a control logic configured for pre-conditioning the at least one series actuator upon entering the AFR mode for enabling rotorcraft control upon occurrence of an in-flight shutdown of the at least one first engine in the AFR mode, wherein pre-conditioning of the at least one series actuator comprises shifting a reduced nominal stroke range authorized for the series actuator stroke of the at least one series actuator in the AEO mode into a reduced shifted stroke range authorized for the series actuator stroke of the at least one series actuator in the AFR mode to enable authorization of an increased stroke range upon occurrence of an IFSD, the increased stroke range being adapted to provide sufficient control authority required for a recovery maneuver in response to occurrence of an IFSD.

A method of controlling flight operation of a rotorcraft, wherein the rotorcraft comprises:

• at least one main rotor with at least one main rotor actuator for adapting main rotor control dependent on a current flight condition of the rotorcraft wherein main rotor actuator stroke of the at least one main rotor actuator is adjusted via series actuator stroke of at least one series actuator arranged upstream of the at least one main rotor actuator, and wherein the at least one series actuator is coupled to a control lever that is connected to at least one parallel actuator;
• at least one first engine and at least one second engine for powering the at least one main rotor;
• and a flight control system configured for controlling flight operation of the rotorcraft at least in an All Engines Operative mode, in which the at least one first engine and the at least one second engine are powering the at least one main rotor, or in an asymmetric flight regime mode, in which only the at least one first engine is powering the at least one main rotor, the method comprising:
• providing a control logic configured for pre-conditioning the at least one series actuator upon entering the AFR mode for enabling rotorcraft control upon occurrence of an in-flight shutdown of the at least one first engine in the AFR mode, wherein pre-conditioning of the at least one series actuator comprises shifting a reduced nominal stroke range authorized for the series actuator stroke of the at least one series actuator in the AEO mode into a reduced shifted stroke range authorized for the series actuator stroke of the at least one series actuator in the AFR mode to enable authorization of an increased stroke range upon occurrence of an IFSD, the increased stroke range being adapted to provide sufficient control authority required for a recovery maneuver in response to occurrence of an IFSD.