Abstract: A start-up system including a control system controlling a partial opening of an air intake valve of a start-up turbine during a first phase of the start-up. The start-up turbine is capable of turning a rotor of the turbomachine for the purpose of the start-up, so as to prevent the rotor from encountering critical frequencies of the turbomachine.

Abstract: The start-up system comprises a control loop, which regulates in real time the opening of a valve of an air feed of a start-up turbine based on the current measured speed of rotation of a rotor of the turbomachine and a predetermined speed value, said start-up turbine being capable of turning the rotor of the turbomachine for the purpose of the start-up.

Abstract: The aircraft includes at least one engine having contra-rotating rotors, the engine or at least one of the engines having imbalances associated with at least one ellipse. The aircraft includes a means capable of controlling the engine or at least one of the engines such that, at a given engine speed, the large axis of the ellipse or at least one of the ellipses extends in a direction for which the vibrations generated by the engine or engines have a minimum intensity in at least one predetermined site, particularly in a predetermined area, of the aircraft.

Abstract: The start-up system comprises a control loop, which regulates in real time the opening of a valve of an air feed of a start-up turbine based on the current measured speed of rotation of a rotor of the turbomachine and a predetermined speed value, said start-up turbine being capable of turning the rotor of the turbomachine for the purpose of the start-up.

Abstract: A start-up system including a control system controlling a partial opening of an air intake valve of a start-up turbine during a first phase of the start-up.

Abstract: An aircraft including at least one engine having counter-rotating rotors, the engine or at least one of the engines having imbalances associated with at least one ellipse. The aircraft includes at least one vibration damper attached in an arrangement such that, at a given engine speed and for at least one given common direction of a large axis of the ellipse or at least one of the ellipses, a speed related to the two ends of the damper is higher than for any other arrangement of the damper.

Abstract: An aircraft has a vertical fin fastened to the rear and above a fuselage of elongated form, essentially in a vertical plane of symmetry of the aircraft. The vertical fin has at least two stable positions, an extended position and a returned position, such that a surface of the vertical fin, subjected to an aerodynamic flow when the aircraft is in flight, is modified in position or in surface between the returned position and the extended position, so that the aerodynamic drag of the vertical fin is reduced in the returned position under given flight conditions compared to the extended position. The change from one surface to another of the vertical fin is accomplished by modifying the geometry of the vertical fin or by displacing the vertical fin relative to the fuselage so that the vertical fin, for example, is more or less inside the fuselage, or more or less immersed in the wake zone of the fuselage in which the local dynamic pressure Pd is reduced relative to the infinitely upstream dynamic pressure Pd0.

Abstract: The aircraft includes at least one engine having counter-rotating rotors, the engine or at least one of the engines having imbalances associated with at least one ellipse. The aircraft includes a means capable of controlling the engine or at least one of the engines such that, at a given engine speed, the large axis of the ellipse or at least one of the ellipses extends in a direction for which the vibrations generated by the engine or engines have a minimum intensity in at least one predetermined site, particularly in a predetermined area, of the aircraft.

Abstract: An aircraft including at least one engine having counter-rotating rotors, the engine or at least one of the engines having imbalances associated with at least one ellipse. The aircraft includes at least one vibration damper attached in an arrangement such that, at a given engine speed and for at least one given common direction of a large axis of the ellipse or at least one of the ellipses, a speed related to the two ends of the damper is higher than for any other arrangement of the damper.

Abstract: An aircraft has a vertical fin fastened to the rear and above a fuselage of elongated form, essentially in a vertical plane of symmetry of the aircraft. The vertical fin has at least two stable positions, an extended position and a returned position, such that a surface of the vertical fin, subjected to an aerodynamic flow when the aircraft is in flight, is modified in position or in surface between the returned position and the extended position, so that the aerodynamic drag of the vertical fin is reduced in the returned position under given flight conditions compared to the extended position. The change from one surface to another of the vertical fin is accomplished by modifying the geometry of the vertical fin or by displacing the vertical fin relative to the fuselage so that the vertical fin, for example, is more or less inside the fuselage, or more or less immersed in the wake zone of the fuselage in which the local dynamic pressure Pd is reduced relative to the infinitely upstream dynamic pressure Pd0.

Abstract: The articulated device (10) that is intended for filtering vibrational movements from a vehicle floor (12) and transmitted to a passenger support (19), is installed between said floor (12) and said support (19), and comprises two mounts (20) fixed to the vehicle floor (12), one mobile central part (22) articulated to the support (19), two connecting rods (24), each articulated to one of the mounts (20) and the central part (22). These five elements (20, 22, 24) are articulated to each other and to the support (19) by rotation joints, the rotations operating about five rotation axes (32, 34, 36) that are parallel to each other. The system (100) for filtering vibrational movements transmitted to a passenger support (19) comprises at least three filtering devices (10), such that the support (19) moves in translation along a plane curved trajectory. To be used for an aircraft seat.

Abstract: The articulated device (10) that is intended for filtering vibrational movements from a vehicle floor (12) and transmitted to a passenger support (19), is installed between said floor (12) and said support (19), and comprises two mounts (20) fixed to the vehicle floor (12), one mobile central part (22) articulated to the support (19), two connecting rods (24), each articulated to one of the mounts (20) and the central part (22). These five elements (20, 22, 24) are articulated to each other and to the support (19) by rotation joints, the rotations operating about five rotation axes (32, 34, 36) that are parallel to each other.