Abstract: The present invention relates to a control method in case of engine failure of a hybrid helicopter having a power plant connected to at least one lift rotor and to at least one propeller, said lift rotor having a plurality of first blades and said at least one propeller having a plurality of second blades. The method comprises the following steps: (i) measuring a forward speed of the hybrid helicopter, (ii) on condition that said forward speed is greater than a first speed threshold and that each engine has failed, automatically implementing a first emergency piloting mode comprising a step for automatic reduction by an automatic piloting system of a pitch of said second blades toward an objective pitch making said at least one propeller produce a motive power which is transmitted to the lift rotor.

Abstract: A method for optimizing the operation of at least one first propeller and of at least one second propeller of a hybrid helicopter. The method comprises the following step during a control phase: deflection, with an autopilot system, of at least one aerodynamic stabilizer member into a setpoint position having, with respect to a reference position, a target deflection angle that is a function of a setpoint deflection angle, the setpoint deflection angle being calculated by the autopilot system in order to compensate for a torque exerted by the lift rotor at zero sideslip.

Abstract: A method of controlling at least a first pitch of a first propeller and a second pitch of a second propeller of a hybrid helicopter, the hybrid helicopter having a thrust control and a yaw control that are configured to generate orders for modifying respectively a mean pitch component and a differential pitch component of the first pitch and of the second pitch, the hybrid helicopter having a collective pitch control for modifying a collective pitch component of main blades of the lift rotor. The method includes a step of: keeping with the control system the first pitch and the second pitch within a control domain that varies as a function of information relating to the collective pitch component.

Abstract: A method of providing torque protection and/or thrust protection for the or each propeller of a hybrid helicopter. The hybrid helicopter includes a control system connected to the blades of each propeller and a thrust control configured to generate an order for modifying a pitch of the blades, which order is transmitted to the control system, the propeller(s) being driven in rotation by a mechanical transmission system of the hybrid helicopter. The method includes a step of having the control system keep the pitch of the blades of a propeller within at least one control envelope relating to a thrust generated by the propeller or to a torque exerted in the mechanical transmission system. In this way, the pitch of the blades of each propeller is kept between a lower limit and an upper limit of the control envelope.

Abstract: A method for controlling a hybrid helicopter having at least one lifting rotor, at least one forward-movement propeller and an empennage provided with at least one moveable empennage surface. The method includes the following steps: using a main sensor to determine a current value of a rotor parameter conditioning a current power drawn by the lifting rotor, using an estimator to determine a current setpoint of the rotor parameter, adjusting a position of the moveable empennage surface using a deflection controller as a function of the current value and of current setpoint.

Abstract: A method of protecting a margin for controlling the yaw attitude of a hybrid helicopter that includes a lift rotor as well as at least one first propeller and at least one second propeller. A thrust control is configured to generate at least a first order issued to increase a first pitch of first blades of the first propeller and a second pitch of second blades of the second propeller. After a first order has been issued, the method includes an inhibition step for having a control computer inhibit the first order when a yaw attitude control margin, with regard to an envelope delimiting a flight control domain, is and/or will be less than or equal to a threshold.

Abstract: A method for controlling a hybrid helicopter having at least one lifting rotor, at least one forward-movement propeller and an empennage provided with at least one moveable empennage surface. The method includes the following steps: using a main sensor to determine a current value of a rotor parameter conditioning a current power drawn by the lifting rotor, using an estimator to determine a current setpoint of the rotor parameter, adjusting a position of the moveable empennage surface using a deflection controller as a function of the current value and of current setpoint.

Abstract: A method of automatically adjusting lift in a hybrid rotorcraft, the hybrid rotorcraft including a fuselage and at least two half-wings on either side of the fuselage, the at least two half-wings including at least one left half-wing having a left fixed structure secured to the fuselage and at least one left flap mounted to move relative to the left fixed structure, and at least one right half-wing having a right fixed structure secured to the fuselage and at least one right flap mounted to move relative to the right fixed structure. The method determines at least one first deflection angle setpoint ?w1 by which the at least one left flap is to be deflected relative to the left fixed structure and at least one second deflection angle setpoint ?w2 by which the at least one right flap is to be deflected relative to the right fixed structure.

Abstract: A method of protecting a margin for controlling the yaw attitude of a hybrid helicopter that includes a lift rotor as well as at least one first propeller and at least one second propeller. A thrust control is configured to generate at least a first order issued to increase a first pitch of first blades of the first propeller and a second pitch of second blades of the second propeller. After a first order has been issued, the method includes an inhibition step for having a control computer inhibit the first order when a yaw attitude control margin, with regard to an envelope delimiting a flight control domain, is and/or will be less than or equal to a threshold.

Abstract: A method of providing torque protection and/or thrust protection for the or each propeller of a hybrid helicopter. The hybrid helicopter includes a control system connected to the blades of each propeller and a thrust control configured to generate an order for modifying a pitch of the blades, which order is transmitted to the control system, the propeller(s) being driven in rotation by a mechanical transmission system of the hybrid helicopter. The method includes a step of having the control system keep the pitch of the blades of a propeller within at least one control envelope relating to a thrust generated by the propeller or to a torque exerted in the mechanical transmission system. In this way, the pitch of the blades of each propeller is kept between a lower limit and an upper limit of the control envelope.

Abstract: A method of controlling at least a first pitch of a first propeller and a second pitch of a second propeller of a hybrid helicopter, the hybrid helicopter having a thrust control and a yaw control that are configured to generate orders for modifying respectively a mean pitch component and a differential pitch component of the first pitch and of the second pitch, the hybrid helicopter having a collective pitch control for modifying a collective pitch component of main blades of the lift rotor. The method includes a step of: keeping with the control system the first pitch and the second pitch within a control domain that varies as a function of information relating to the collective pitch component.

Abstract: A method for optimizing the operation of at least one first propeller and of at least one second propeller of a hybrid helicopter. The method comprises the following step during a control phase: deflection, with an autopilot system, of at least one aerodynamic stabilizer member into a setpoint position having, with respect to a reference position, a target deflection angle that is a function of a setpoint deflection angle, the setpoint deflection angle being calculated by the autopilot system in order to compensate for a torque exerted by the lift rotor at zero sideslip.

Abstract: A method of automatically adjusting lift in a hybrid rotorcraft, the hybrid rotorcraft including a fuselage and at least two half-wings on either side of the fuselage, the at least two half-wings including at least one left half-wing having a left fixed structure secured to the fuselage and at least one left flap mounted to move relative to the left fixed structure, and at least one right half-wing having a right fixed structure secured to the fuselage and at least one right flap mounted to move relative to the right fixed structure. The method determines at least one first deflection angle setpoint ?w1 by which the at least one left flap is to be deflected relative to the left fixed structure and at least one second deflection angle setpoint ?w2 by which the at least one right flap is to be deflected relative to the right fixed structure.

Abstract: The present invention relates to a control method in case of engine failure of a hybrid helicopter having a power plant connected to at least one lift rotor and to at least one propeller, said lift rotor having a plurality of first blades and said at least one propeller having a plurality of second blades. The method comprises the following steps: (i) measuring a forward speed of the hybrid helicopter, (ii) on condition that said forward speed is greater than a first speed threshold and that each engine has failed, automatically implementing a first emergency piloting mode comprising a step for automatic reduction by an automatic piloting system of a pitch of said second blades toward an objective pitch making said at least one propeller produce a motive power which is transmitted to the lift rotor.

Abstract: A hybrid type rotorcraft having a main rotor, at least two propulsion elements each mounted on respective half-wings arranged symmetrically on either side of an anteroposterior midplane XOZ, a horizontal stabilizer arranged in a rear zone of the rotorcraft on either side of the anteroposterior midplane XOZ, and two fins arranged respectively on either side of the anteroposterior midplane XOZ, each of the two fins comprising a respective left/right bottom fin airfoil arranged below the horizontal stabilizer and a respective left/right top fin airfoil arranged above the horizontal stabilizer.

Abstract: A hybrid type rotorcraft having a main rotor, at least two propulsion elements each mounted on respective half-wings arranged symmetrically on either side of an anteroposterior midplane XOZ, a horizontal stabilizer arranged in a rear zone of the rotorcraft on either side of the anteroposterior midplane XOZ, and two fins arranged respectively on either side of the anteroposterior midplane XOZ, each of the two fins comprising a respective left/right bottom fin airfoil arranged below the horizontal stabilizer and a respective left/right top fin airfoil arranged above the horizontal stabilizer.