Abstract: An aircraft (1) provided with a main gearbox (3) fastened to a load-bearing structure (2) via at least three suspension bars (5). An active vibration absorber (10) is fastened around each suspension bar (5), each vibration absorber (10) being provided with a first mass (11) connected to the associated suspension bar (5) via first resilient means (21), and with a second mass (12) connected to the first mass (11) via second resilient means (22), said vibration absorber (10) having a force generator (15) interposed between the first mass (11) and the second mass (12) and inputting a control force on being instructed by a control unit (16) as a function of information coming from at least one first measurement sensor (17) for sensing monitoring parameters for monitoring the associated suspension bar.

Abstract: An aircraft (1) provided with a main gearbox (3) fastened to a load-bearing structure (2) via at least three suspension bars (5). An active vibration absorber (10) is fastened around each suspension bar (5), each vibration absorber (10) being provided with a first mass (11) connected to the associated suspension bar (5) via first resilient means (21), and with a second mass (12) connected to the first mass (11) via second resilient means (22), said vibration absorber (10) having a force generator (15) interposed between the first mass (11) and the second mass (12) and inputting a control force on being instructed by a control unit (16) as a function of information coming from at least one first measurement sensor (17) for sensing monitoring parameters for monitoring the associated suspension bar.

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: System for minimizing the dynamic excitation at the center of gravity of the fuselage of a helicopter, this excitation being brought about by the forces transmitted between the main transmission box and the fuselage, these two components being joined together by suspension bars which each have an elastic linkage device.According to the invention, each elastic linkage device (2) comprises a cylinder (10), subdivided into two chambers (11, 12) by a piston (13) connected by springs to the two corresponding opposite internal faces (10a, 10b) of the cylinder (10), and the chambers (11, 12) of the cylinder (10) are additionally connected to one another by a pipe (17) which has a small cross section compared with that of the cylinder (10). A computer (6) pilots the movement of liquid in said pipe (17).

Abstract: A gunsight device for a rotating-wing aircraft having a hollow rotor hub (1), on which there are radially mounted blades constituting said rotating wing, and which is connected to the main transmission box (2) by a drive shaft coaxial with the rotor of the aircraft. The device includes a nonrotating gunsight head (3) mounted, by means of a support (4), at the free upper end (5a) of a nonrotating mast (5) arranged coaxially inside the hub (1) and the drive shaft of the rotor, the other end (5b) of which mast is fixed into the main transmission box (2), a rolling contact bearing (6) coaxial with the rotor axis being provided between the hub (1) and the mast (5). A suspension (7), intended to filter out the excitations in roll and in pitch to which said gunsight head (3) is subjected, is provided between the base (4a) of the support (4) of the gunsight head (3) and the upper end (5 a) of the mast (5).

Abstract: The present invention relates to a device for elastic linking between two parts (3, 5) in order to filter the vibratory excitations which are transmitted from one to the other, comprising:at least one linking element (7) between said parts (3, 5) comprising a transmission member (8) for the static force between said parts (3, 5), and an actuator (9) associated with said transmission member (8),at least one means of measurement (10) of a physical quantity which is representative of said vibratory excitations, and able to supply corresponding first signals, andelectronic processing means (12) for said first signals in order to convert them into second control signals for said actuator (9).According to the invention, said measurement means (10) is mounted on said linking element (7).