Abstract: A variable-pitch, multi-blade propeller specially usable as a rear rotor of a rotary-wing aircraft and a process for manufacturing the same are described. The propeller comprises a number of pairs of blades emanating from a central hub, each pair comprising a single elongate strip secured at its center to the hub. The strip is composed of two flat bundles of fibres and defining an aperture for a sliding shaft at their center. The shaft is used to control the pitch angles of the blades and aerodynamic blade shells are secured to the fibre bundles by adhesive synthetic cellular or foam material.

Abstract: The invention relates to a device for damping the vibrations of a rotary-wing aircraft rotor. An annular weight is disposed concentrically of the rotor axis. This weight is supported by at least three resiliently deformable elements such as helical springs, radially biased in directions distributed regularly around the rotor axis. The inner ends of the springs directly bear on a part extending the rotor shaft axially. Their outer ends directly bear on the annular weight so that the spring apply statically balanced centrifugal thrusts to the annular weight. The springs are so still that they support the annular weight without substantially bending.

Abstract: The invention relates to a device for damping the vibrations of the rotor of a rotary-wing aircraft. This device comprises a flapping weight concentrated near the rotor axis and at least three resiliently deformable elements, such as helical springs. The deformable elements are radially biassed in directions regularly distributed around the rotor axis. The inner ends of the deformable elements directly bear on the flapping weight. Their outer ends directly bear on rigid structure elements, rigidly secured to the rotor hub, so that the biassed deformable elements apply statically balanced centripetal thrusts to the flapping weight.