A system and method for protecting a rotorcraft from entering a vortex ring state, the method including monitoring a vertical speed of a rotorcraft, comparing the vertical speed to a vertical speed safety threshold, and performing vortex ring state (VRS) avoidance in response to the vertical speed exceeding the vertical speed safety threshold. The performing the VRS avoidance includes determining a power margin available from one or more engines of the rotorcraft, limiting the vertical speed of the rotorcraft in response to the power margin exceeding a threshold, and increasing a forward airspeed of the rotorcraft in response to the power margin not exceeding the threshold.

A system and method for protecting a rotorcraft from entering a vortex ring state, the method including monitoring a vertical speed of a rotorcraft, comparing the vertical speed to a vertical speed safety threshold, and performing vortex ring state (VRS) avoidance in response to the vertical speed exceeding the vertical speed safety threshold. The performing the VRS avoidance includes determining a power margin available from one or more engines of the rotorcraft, limiting the vertical speed of the rotorcraft in response to the power margin exceeding a threshold, and increasing a forward airspeed of the rotorcraft in response to the power margin not exceeding the threshold.

A helicopter autopilot system includes an inner loop for attitude hold for the flight of the helicopter including a given level of redundancy applied to the inner loop. An outer loop is configured for providing a navigation function with respect to the flight of the helicopter including a different level of redundancy than the inner loop. An actuator provides a braking force on a linkage that serves to stabilize the flight of the helicopter during a power failure. The actuator is electromechanical and receives electrical drive signals to provide automatic flight control of the helicopter without requiring a hydraulic assistance system in the helicopter. The autopilot can operate the helicopter in a failed mode of the hydraulic assistance system. A number of flight modes are described with associated sensor inputs including rate based and true attitude modes.

A helicopter autopilot system includes an inner loop for attitude hold for the flight of the helicopter including a given level of redundancy applied to the inner loop. An outer loop is configured for providing a navigation function with respect to the flight of the helicopter including a different level of redundancy than the inner loop. An actuator provides a braking force on a linkage that serves to stabilize the flight of the helicopter during a power failure. The actuator is electromechanical and receives electrical drive signals to provide automatic flight control of the helicopter without requiring a hydraulic assistance system in the helicopter. The autopilot can operate the helicopter in a failed mode of the hydraulic assistance system. A number of flight modes are described with associated sensor inputs including rate based and true attitude modes.

A method of controlling rotor moments includes receiving, in a flight control computer (FCC) a rotor moment reference value based on pilot inceptor inputs, sensing rotor moment from one or more sensors, receiving, in the FCC, a rotary wing aircraft condition parameter, and establishing, through the FCC, a rotor blade pitch angle for one or more of a plurality of rotor blades that counteracts external forces acting upon the rotary wing aircraft.

A method of controlling rotor moments includes receiving, in a flight control computer (FCC) a rotor moment reference value based on pilot inceptor inputs, sensing rotor moment from one or more sensors, receiving, in the FCC, a rotary wing aircraft condition parameter, and establishing, through the FCC, a rotor blade pitch angle for one or more of a plurality of rotor blades that counteracts external forces acting upon the rotary wing aircraft.

A device for assisting the piloting of a rotorcraft in order to pilot a rotorcraft during an approach stage preceding a stage of landing on a rotorcraft landing area. Such a device includes in particular a camera for taking a plurality of images of the environment of the rotorcraft along a line of sight, looking at least along a forward direction Dx of the rotorcraft, and processor means for identifying in at least one image from among said plurality of images at least one looked-for landing area.

A torque measurement system determines torque on a shaft by monitoring angular deflection of the shaft under load using phase shift measurements. Calibration of the system uses a defined offset that is determined using a reference operating condition. The offset calibration value is determined for a rotorcraft using the following steps: defining a reference operational condition in which the shaft is rotating, estimating the torque at the reference condition based on aerodynamic knowledge of the rotors coupled to the shaft, operating the shaft at the reference operational condition, capturing sensor data to determine the phase difference at the operational condition, and associating the phase difference and an estimated torque as a calibration value to enable calculation of torque in the torque measurement system.

A torque measurement system determines torque on a shaft by monitoring angular deflection of the shaft under load using phase shift measurements. Calibration of the system uses a defined offset that is determined using a reference operating condition. The offset calibration value is determined for a rotorcraft using the following steps: defining a reference operational condition in which the shaft is rotating, estimating the torque at the reference condition based on aerodynamic knowledge of the rotors coupled to the shaft, operating the shaft at the reference operational condition, capturing sensor data to determine the phase difference at the operational condition, and associating the phase difference and an estimated torque as a calibration value to enable calculation of torque in the torque measurement system.

A method of reducing the noise generated in-flight by a vortex wake caused by each first blade of a main rotor of a hybrid helicopter. The hybrid helicopter includes a main rotor, at least two wings and at least one propeller. The method enables a stabilized flight phase on the level or with a non-zero aerodynamic slope to be implemented by determining a first value of the pitch of the second blades of each propeller and an angle of incidence of the main rotor as function of the flight conditions, then by applying the first pitch value to each propeller and by applying the angle of incidence to the main rotor so as to direct the vortex wake to limit the noisy interactions between the vortex wake and the other first blades and/or the second blades.