Antiresonant suspension device for helicopter

An anti-resonant suspension system for supporting the rotor and gear box of a helicopter on the fuselage thereof comprising a mounting plate having a central part on which is secured the bottom of the gear box and a plurality of radially extending flexible arms disposed coplanar uniformly about the central axis of said gear box, said arms being rigid within their plane and flexible in a direction perpendicular thereto, each of said arms being joined at its end to said fuselage, a plurality of oblique connecting bars corresponding in number to the number of said arms, said bars being joined at one end to the upper end of said gear box and at its other end to a respective one of said arms at a point along said arm adjacent to but spaced latterally from the joint between said arms and said fuselage, said respective joints permitting flexing of each of said arms along their length by deformation in a direction perpendicular to the plane of said arms, each of said arms having a lever integral with its outer end and extending freely therefrom in the plane of said arm, said lever having a flapping weight secured to the free end thereof substantially coplanar with said arm.