Abstract: A blade in which the aerodynamic profiles of a blade root, a blade neck and a central part of a profiled zone of the blade respectively comprise a leading edge section and a trailing edge section that are symmetrical to each other relative to an axis of symmetry. The present disclosure also concerns a method for constructing such a blade. The axis of symmetry is perpendicular to a segment connecting the leading edge to the trailing edge of each profile and is positioned in the middle of the segment. An intermediate upper surface section and an intermediate lower surface section connect the leading edge section and the trailing edge section in order to respectively form a lower surface of the aerodynamic profile.

Abstract: A method for controlling a thermal and electrical power plant for setting in motion at least one rotary member of a rotorcraft, the power plant comprising at least one heat engine and an electrical system provided with at least one electric machine. The method comprises: selecting, with a selector, an operating mode chosen from several operating modes; determining a density altitude and comparing, with a controller, the current density altitude and a threshold density altitude; and controlling, with the controller, the at least one electric machine depending on at least the chosen operating mode as well as the comparison and a necessary power to be supplied to the power transmission system.

Abstract: A rotorcraft and to a regulation method for regulating a power plant of a rotorcraft, the power plant having two engine units and a main gearbox, the two engine units being suitable for mechanically driving the main gearbox in order to drive an outlet main shaft of the main gearbox in rotation, the outlet main shaft being constrained to rotate with a main rotor of the rotorcraft, the two engine units including a first engine unit including at least one main engine. In accordance with the invention, such a regulation method includes at least one regulation step consisting in regulating a speed of rotation of the at least one main engine by progressively reducing a current setpoint by an increment i in percentage of the current setpoint per second.

Abstract: A blade in which the aerodynamic profiles of a blade root, a blade neck and a central part of a profiled zone of the blade respectively comprise a leading edge section and a trailing edge section that are symmetrical to each other relative to an axis of symmetry. The present disclosure also concerns a method for constructing such a blade. The axis of symmetry is perpendicular to a segment connecting the leading edge to the trailing edge of each profile and is positioned in the middle of the segment. An intermediate upper surface section and an intermediate lower surface section connect the leading edge section and the trailing edge section in order to respectively form a lower surface of the aerodynamic profile.

Abstract: A rotorcraft and to a regulation method for regulating a power plant of a rotorcraft, the power plant having two engine units and a main gearbox, the two engine units being suitable for mechanically driving the main gearbox in order to drive an outlet main shaft of the main gearbox in rotation, the outlet main shaft being constrained to rotate with a main rotor of the rotorcraft, the two engine units including a first engine unit including at least one main engine. In accordance with the invention, such a regulation method includes at least one regulation step consisting in regulating a speed of rotation of the at least one main engine by progressively reducing a current setpoint by an increment i in percentage of the current setpoint per second.