Abstract: An improved feathering flexure for a helicopter rotor system yoke includes, in transverse cross section, a relatively thin central web and six relatively thin flanges. Three flanges extend from each of the web's two edges, and the flanges lie in planes which are approximately radial relative to the neutral feathering axis of the feathering flexure. The feathering flexure is constructed of fiberglass material embedded in a polymer matrix. The web's fiberglass material in the web is bias material, that is, material whose glass fibers are oriented at plus or minus 45 degrees relative to the yoke's spanwise axis. In transverse cross section, each of the flanges includes two unidirectional belts disposed on either side of a bias pack. The glass fibers in the unidirectional belts are oriented parallel to the yoke's spanwise axis. The fiberglass material in the bias packs is bias material.

Abstract: A pitch change bearing assembly for a helicopter hub (10) having a yoke (14) and a grip (12) includes a shaft (24) having first and second ends (24a, 24b). A first radial elastomeric bearing (60) is disposed on the first end (24a) of the shaft (24). A second radial elastomeric bearing (62) is disposed on the second end (24b) of the shaft (24). The first and second radial elastomeric bearings (60, 62) are disposed parallel to one another. A third radial elastomeric bearing (66) is disposed on the shaft between and spaced apart from the first (60) and second (62) radial elastomeric bearings and is parallel to the first and second radial elastomeric bearings (60, 62). Structure (28, 30) is provided for attaching the third radial elastomeric bearing (66) to the grip (12). Structure (48, 50) is further provided for attaching the first and second radial elastomeric bearings (60, 62) to the yoke (14).

Abstract: A composite rotor blade comprising an outboard portion defining an airfoil surface, an inboard portion defining an end tang having a mounting section and an extension lug section. The mounting section of the end tang having at least one mounting aperture with an axis parallel to the chordline of the airfoil for mounting of the blade, and the extension lug section having at least one extension lug extending inboard of the mounting aperture to provide a lever surface for interaction with suitable mounting mechanisms.

Abstract: The system comprises a grip of composite material having belts, filament windings unidirectional material and fillers of off axis bias ply material for directing the CF exerted on the grip by the blade rotation to the clevis throat of the grip. The force is further directed through a CF fitting, a CF bearing and an OPCBA to the yoke, thereby maintaining the yoke in tension. Should this load path fail, the CF will be transmitted through the length of the grip to the IPCBA that will in turn load the yoke with the CF.

Abstract: A pitch change bearing assembly for a helicopter hub (10) having a yoke (14) and a grip (12) includes a shaft (24) having first and second ends (24a, 24b). A first radial elastomeric bearing (60) is disposed on the first end (24a) of the shaft (24). A second radial elastomeric bearing (62) is disposed on the second end (24b) of the shaft (24). The first and second radial elastomeric bearings (60, 62) are disposed parallel to one another. A third radial elastomeric bearing (66) is disposed on the shaft between and spaced apart from the first (60) and second (62) radial elastomeric bearings and is parallel to the first and second radial elastomeric bearings (60, 62). Structure (28, 30) is provided for attaching the third radial elastomeric bearing (66) to the grip (12). Structure (48, 50) is further provided for attaching the first and second radial elastomeric bearings (60, 62) to the yoke (14).