Abstract: A rotorcraft rotor blade assembly includes an upper skin portion extending substantially a full span of the rotor blade assembly and a lower skin portion extending substantially the full span of the rotor blade assembly. Each of the upper skin portion and the lower skin portion is configured to carry at least substantially 30% of rotor blade assembly loads.

Abstract: A rotorcraft rotor blade assembly includes an upper skin portion extending substantially a full span of the rotor blade assembly and a lower skin portion extending substantially the full span of the rotor blade assembly. Each of the upper skin portion and the lower skin portion is configured to carry at least substantially 30% of rotor blade assembly loads.

Abstract: A damper has a piston having an axis, an outer surface, and opposing ends. Elastomeric seals are in sealing contact with the outer surface of the piston, the seals being coaxial with the piston and limiting movement of the piston to a path along the axis of the piston. The seals also define fluid chambers adjacent the ends of the piston. A primary passage communicates the fluid chambers, and a selectively switchable valve for controls a flow of fluid from one of the chambers to another of the chambers through the primary passage. When the flow of fluid through the primary passage is permitted, movement of the piston is resisted by a first spring rate due to a shear force required to cause shear deflection of the seals. When the flow of fluid through the primary passage is restricted, movement of the piston is resisted by a second spring rate due to a fluid force required to cause bulging deflection of the seals.