Abstract: A drive device (D) for driving first and second lift rotors (2, 3) of a twin-rotor rotorcraft, includes link elements provided with first and second transmission shafts (5, 6) for synchronizing the first and second transmission members (74, 84) of first and second main gearboxes (7, 8), the first main gearbox (7) being provided with first power combiner element (73) firstly meshing with the first transmission member (74) and secondly mechanically linked with the first transmission shaft (5) and with the second transmission shaft (6), and the second main gearbox (8) being provided with second power combiner element (83) firstly meshing with the second transmission member (84), and secondly mechanically linked with the first transmission shaft (5) and with the second transmission shaft (6).

Abstract: A drive device (D) for driving first and second lift rotors (2, 3) of a twin-rotor rotorcraft, includes link elements provided with first and second transmission shafts (5, 6) for synchronizing the first and second transmission members (74, 84) of first and second main gearboxes (7, 8), the first main gearbox (7) being provided with first power combiner element (73) firstly meshing with the first transmission member (74) and secondly mechanically linked with the first transmission shaft (5) and with the second transmission shaft (6), and the second main gearbox (8) being provided with second power combiner element (83) firstly meshing with the second transmission member (84), and secondly mechanically linked with the first transmission shaft (5) and with the second transmission shaft (6).

Abstract: The present invention relates to a convertible aircraft provided with first and second tilt fans disposed on either side of the fuselage a little forward of the center of gravity of the convertible aircraft. In addition, the convertible aircraft includes, in remarkable manner, a non-tilting fan that is permanently in a vertical position and that is contained inside the fuselage.

Abstract: The present invention relates to a convertible. aircraft provided with first and second tilt fans disposed on either side of the fuselage a little forward of the center of gravity of the convertible aircraft. In addition, the convertible aircraft includes, in remarkable manner, a non-tilting fan that is permanently in a vertical position and that is contained inside the fuselage.

Abstract: The present invention provides a convertible aircraft provided with first and second tail booms together with first and second tilt fans disposed on either side of the fuselage a little forward of the center of gravity of said aircraft. In addition, the convertible aircraft includes, in remarkable manner, a third tilt fan arranged between the first and second tail booms.

Abstract: Improving convertible aircraft of the aforementioned type mainly in terms of the active control of vibrations, while at the same time avoiding the addition of significant additional masses for essentially countering the excitations caused by the rotors and, secondarily, of making such an aircraft easier to control in terms of roll in airplane mode. In this secondary objective, these improvements aim to allow simplifications to the maneuvering and command means for controlling the aircraft in terms of roll in airplane mode and preferably, at the same time, a simplification of the command and maneuvering means performing the functions of augmenting lift and reducing offsetting power. The invention also relates to improvements made to the convertible aircraft of the aforementioned type to give them the ability to land in airplane mode (without converting beforehand from airplane configuration to helicopter configuration).

Abstract: The convertible aircraft with tilting rotors comprises two fixed wings with zero sweep on which an inter-connecting shaft is substantially rectilinear and parallel with the pivot axis but offset from this axis, substantially perpendicular to a longitudinal axis of symmetry of the aircraft, the center of gravity of which, in helicopter mode, is substantially in a vertical plane passing through the pivot axis and, in aeroplane mode, is substantially contained in or is in proximity to another vertical plane passing through the straight line of the aerodynamic centers of the wings.

Abstract: To provide aerodynamic continuity between the front part, pivoting with the rotor, and the stationary rear part of a pod housing an engine for driving the rotor, a curved cowl curved about the pivot axis extends the rear edge of the bottom cowling of the front part to join this rear edge to the front edge of a bottom cowling of the stationary rear part, in helicopter mode, and a flap swivel-mounted on the top cowling of the front part joins this latter to the top cowling of the stationary rear part, onto which this flap is folded, in helicopter mode.