Abstract: A helicopter rotor hub is provided with a center plate and a plurality of arms projecting from the center plate. Each of the projecting arms has a slot for receiving a flexible element that is connected to a spindle and grip that supports the rotor blades. The rotor blades can accomplish the movements of flapping and lag by allowing the center plate to have a low stiffness in the vertical plane when the center plate lies in a horizontal plane, and the flexible element a low stiffness in the horizontal plane when the flexible elements lie in the vertical plane, thereby acting as virtual hinges. This allows for the possibility of locating the vertical hinges at an equal distance from the rotor axis, and the pitch variation hinge a small distance from the other hinges, allowing for a relatively small dimension of the hub.