Patent attributes
A rotor system of a rotary wing aircraft, such as a helicopter, is provided. The rotor system includes a rotor mast, a rotor hub and at least four, angularly generally even distributed rotor blades and swash plate struts for pitch and subsequently flap control. The rotor blades are pairwise to each other with zero offset to the rotor hub. The rotor hub is provided with a hollow bearing with at least one further bearing inside. A first pair of rotor blades is mounted on the hollow bearing and is pivotable in a first flap direction generally perpendicular to the rotation axis. A second pair of rotor blades is mounted inside the hollow bearing on the at least one further bearing and is pivotable in a second flap direction generally perpendicular to the first flap direction and the rotation axis, and independently of the first pair of rotor blades.