Abstract: The invention relates to a two-bladed tail rotor arrangement for gyroplanes and helicopters, comprising two plates fixed to a rotary shaft, between which are embedded the median portion of a flat flexible spar. On the ends of the said spar are fitted two shells which form the rotor blades and whose cross-section evolves in the blade root area to become circular, whereby the said shells are terminated by cylindrical sleeves fixed by bonding to flanges which are connected by elastic blocks to two plates. The rotor boss assembly can be provided with a cylindrical fairing.

Abstract: A suspension system is disclosed for reducing vibration between the rotor and the structure of a rotary-wing aircraft having a reduction-gear train coextensive with the shaft of the lift rotor. The housing of said gear train is supported by tie-rods and by a flexible beam having its mid-point attached to said housing and its extremities attached to the aircraft structure through the medium of flexible blocks. The beam may be made of metal or a composite material.

Abstract: A rotor for a rotating wing aircraft has a star-shaped hub each arm of which supports a blade. The yoke between each blade and arm is a two tine fork constituted by a continuation of the blade root.

Abstract: A joint for homokynetic transmission of rotary motion between two concurrent shafts of which head portions are mounted. The head portions are connected by pairs of articulated driving-rods each slidably and rotatably disposed in a respective bore in a respective head portion. All the pairs of rods ensure the rotary transmission, and both head portions are also hinge-coupled with double articulation line by means of coupling-boxes loosely mounted on the head portions.

Abstract: An improved rotor for a helicopter comprises a yoke at the inner end of each arm engaging the rotor hub by way of a spherical abutment.