Abstract: A method of manufacturing a tiltrotor wing structure including providing a spar mold having a plurality of bores extending from an exterior surface of the mold to an interior surface of the mold, the plurality of bores corresponding to a plurality of primary coordination holes in a spar member, the spar mold having a periphery defined by a top edge, a bottom edge and outboard ends; selecting a plurality of resin impregnated plies to ensure that the plies continuously extend beyond the periphery of the spar mold; laying the plies in the spar mold; curing the plies in the mold to form a cured spar member that extends beyond the periphery of the spar mold; and accurately drilling a plurality of primary coordination holes in the cured spar member in the spar mold using a tool positioned in the plurality of bores.

Abstract: A method of manufacturing a tiltrotor wing structure including providing a spar mold having a plurality of bores extending from an exterior surface of the mold to an interior surface of the mold, the plurality of bores corresponding to a plurality of primary coordination holes in a spar member, the spar mold having a periphery defined by a top edge, a bottom edge and outboard ends; selecting a plurality of resin impregnated plies to ensure that the plies continuously extend beyond the periphery of the spar mold; laying the plies in the spar mold; curing the plies in the mold to form a cured spar member that extends beyond the periphery of the spar mold; and accurately drilling a plurality of primary coordination holes in the cured spar member in the spar mold using a tool positioned in the plurality of bores.

Abstract: A pitch control system for blades on a rotor of an aircraft has a gimballing rotor hub (31) and a plurality of step-over arms (61) connected to the hub and capable of pivoting relative to the hub about a pivot axis. Each of a plurality of pitch links (55) connects one of the step-over arms (61) to a flight control system for pivoting the connected step-over arm (61) about the pivot axis and relative to the hub in response to inputs from the control system. Each of a plurality of step-over links (69) connects one of the step-over arms (61) to one of the blades for rotating the associated blade about the pitch axis in response to pivoting of the associated step-over arm.

Abstract: An assembly for providing flexure to a blade of a rotary blade system includes an upper support plate having an upper curved surface, a lower support plate having a lower curved surface, and a yoke positioned therebetween. At least one of the upper and lower yoke surfaces has a layer of cushioning material positioned thereon and secured thereto. An alternate embodiment includes an assembly for providing flexure to a blade of a rotary blade system, including, an upper support plate having an upper curved surface, a lower support plate having a lower curved surface, and a yoke positioned therebetween and directly contacting the support plates wherein one of the curved surfaces is a non-circular arc that does not form part of the circumference of a circle. Another alternate embodiment includes a similar assembly having a twist-shank type of yoke for providing rotation of attached blades about their respective pitch axes.

Abstract: A pitch control system for blades on a rotor of an aircraft has a gimballing rotor hub (31) and a plurality of step-over arms (61) connected to the hub and capable of pivoting relative to the hub about a pivot axis. Each of a plurality of pitch links (55) connects one of the step-over arms (61) to a flight control system for pivoting the connected step-over arm (61) about the pivot axis and relative to the hub in response to inputs from the control system. Each of a plurality of step-over links (69) connects one of the step-over arms (61) to one of the blades for rotating the associated blade about the pitch axis in response to pivoting of the associated step-over arm.

Abstract: An assembly for providing flexure to a blade of a rotary blade system includes an upper support plate having an upper curved surface, a lower support plate having a lower curved surface, and a yoke positioned therebetween. At least one of the upper and lower yoke surfaces has a layer of cushioning material positioned thereon and secured thereto. An alternate embodiment includes an assembly for providing flexure to a blade of a rotary blade system, including, an upper support plate having an upper curved surface, a lower support plate having a lower curved surface, and a yoke positioned therebetween and directly contacting the support plates wherein one of the curved surfaces is a non-circular arc that does not form part of the circumference of a circle. Another alternate embodiment includes a similar assembly having a twist-shank type of yoke for providing rotation of attached blades about their respective pitch axes.