Abstract: A notch treatment method for flaw simulation including providing the specimen with the notch, the notch having a re-melt material layer; isolating the notch; and selectively etching the notch to provide an etched surface of the notch; wherein at least a portion of the re-melt material layer has been removed from the notch. In one aspect, there is provided a notch treatment method for flaw simulation including providing the specimen with the notch, the notch having a re-melt material layer, the specimen includes steel or an alloy thereof; isolating the notch; and selectively etching the notch with a first etching solution and a second etching solution to provide an etched surface on the notch; wherein at least a portion of the re-melt material layer has been removed from the notch.

Abstract: An inboard bearing attachment for carrying centrifugal force (“CF”) loads in a rotor blade assembly of a rotorcraft includes a CF fitting having a curved surface and a shear bearing retainer aligned with the curved surface. A mounting flange connected to either the CF fitting or the shear bearing retainer is used to mount the inboard bearing attachment to a yoke.

Abstract: The present invention includes a rotor-blade span-balancing system, including a span-balance pocket in a surface of a rotor blade; a cover operably configured to cover the span-balance pocket, wherein the cover is operably configured to be substantially flush with the surface of the rotor blade surface when covering the span-balance pocket, and wherein the cover includes a cover boss for reacting centrifugal force of the cover into the rotor blade; and one or more span-balance weights attached to the cover to span-balance the rotor blade.

Abstract: In some embodiments, a method of manufacturing composite laminate, including providing a first fibrous material having a plurality of fibers, providing a second fibrous material having a plurality of fibers, disposing the fibers of the first fibrous material in a first polymeric matrix, disposing the fibers of the second fibrous material in a second polymeric matrix, laying up a plurality of the first fibrous material on a rigid structure, laying up the second fibrous material on the rigid structure, wherein the first fibrous material is in contact with the second fibrous material, curing the first polymeric matrix, creating a plurality of baseline layers from the plurality of first fibrous material and the first polymeric matrix, and curing the second polymeric matrix, creating a compliant layer from the second fibrous material and the second polymeric matrix. The compliant layer is stronger than each individual baseline layers.

Abstract: A notch treatment method for flaw simulation including providing the specimen with the notch, the notch having a re-melt material layer; isolating the notch; and selectively etching the notch to provide an etched surface of the notch; wherein at least a portion of the re-melt material layer has been removed from the notch. In one aspect, there is provided a notch treatment method for flaw simulation including providing the specimen with the notch, the notch having a re-melt material layer, the specimen includes steel or an alloy thereof; isolating the notch; and selectively etching the notch with a first etching solution and a second etching solution to provide an etched surface on the notch; wherein at least a portion of the re-melt material layer has been removed from the notch.

Abstract: In some embodiments, a rotor system for a rotorcraft includes a yoke, a blade, and a grip that is configured to couple the blade to the yoke. The grip has a plurality of baseline layers and a compliant layer. The baseline layers each have a plurality of fibers disposed in a first polymeric matrix. The compliant layer has a plurality of fibers disposed in a second polymeric matrix. The compliant layer is stronger than the baseline layer and the first polymeric matrix has a different chemical composition than the second polymeric matrix.

Abstract: A notch treatment method for flaw simulation including providing the specimen with the notch, the notch having a re-melt material layer; isolating the notch; and selectively etching the notch to provide an etched surface of the notch; wherein at least a portion of the re-melt material layer has been removed from the notch. In one aspect, there is provided a notch treatment method for flaw simulation including providing the specimen with the notch, the notch having a re-melt material layer, the specimen includes steel or an alloy thereof; isolating the notch; and selectively etching the notch with a first etching solution and a second etching solution to provide an etched surface on the notch; wherein at least a portion of the re-melt material layer has been removed from the notch.

Abstract: In some embodiments, a method of manufacturing composite laminate, including providing a first fibrous material having a plurality of fibers, providing a second fibrous material having a plurality of fibers, disposing the fibers of the first fibrous material in a first polymeric matrix, disposing the fibers of the second fibrous material in a second polymeric matrix, laying up a plurality of the first fibrous material on a rigid structure, laying up the second fibrous material on the rigid structure, wherein the first fibrous material is in contact with the second fibrous material, curing the first polymeric matrix, creating a plurality of baseline layers from the plurality of first fibrous material and the first polymeric matrix, and curing the second polymeric matrix, creating a compliant layer from the second fibrous material and the second polymeric matrix. The compliant layer is stronger than each individual baseline layers.

Abstract: A notch treatment method for flaw simulation including providing the specimen with the notch, the notch having a re-melt material layer; isolating the notch; and selectively etching the notch to provide an etched surface of the notch; wherein at least a portion of the re-melt material layer has been removed from the notch. In one aspect, there is provided a notch treatment method for flaw simulation including providing the specimen with the notch, the notch having a re-melt material layer, the specimen includes steel or an alloy thereof; isolating the notch; and selectively etching the notch with a first etching solution and a second etching solution to provide an etched surface on the notch; wherein at least a portion of the re-melt material layer has been removed from the notch.

Abstract: A method of monitoring usage of a component of an aircraft can include: monitoring a usage of the component by using a torque measurement system to calculate torque events in a time period; categorizing the usage of the component by assigning a usage value based upon whether the number of torque events in the period of time is above or below a threshold; and determining a life used of the component.

Abstract: An inboard bearing attachment for carrying centrifugal force (“CF”) loads in a rotor blade assembly of a rotorcraft includes a CF fitting having a curved surface and a shear bearing retainer aligned with the curved surface. A mounting flange connected to either the CF fitting or the shear bearing retainer is used to mount the inboard bearing attachment to a yoke.

Abstract: The present invention includes a rotor-blade span-balancing system, including a span-balance pocket in a surface of a rotor blade; a cover operably configured to cover the span-balance pocket, wherein the cover is operably configured to be substantially flush with the surface of the rotor blade surface when covering the span-balance pocket, and wherein the cover includes a cover boss for reacting centrifugal force of the cover into the rotor blade; and one or more span-balance weights attached to the cover to span-balance the rotor blade.

Abstract: An apparatus comprising a soft in plane rotor yoke comprising two longitudinal side portions connected together via two outboard portions, wherein the outboard portions comprise a plurality of first layers formed of a first composite fabric material having a plurality of first fibers oriented in a first direction, and a plurality of second layers formed of a second composite fabric material having a plurality of second fibers oriented in a second direction. Included is an apparatus comprising a soft in plane rotor comprising two longitudinal side portions connected together via two outboard portions, wherein the outboard portions comprise a plurality of first layers formed of a first composite fabric material, and a plurality of second layers formed of a second composite fabric material, wherein the soft in plane rotor yoke does not comprise any narrow steered slit tape or filament windings.

Abstract: A method of repairing a core stiffened structure, including removing a damaged portion of the core stiffened structure; bonding a shelf onto a first core member; bonding a second core member to a shelf; and securing a skin patch over the second core member.

Abstract: An apparatus comprising a soft in plane rotor yoke comprising two longitudinal side portions connected together via two outboard portions, wherein the outboard portions comprise a plurality of first layers formed of a first composite fabric material having a plurality of first fibers oriented in a first direction, and a plurality of second layers formed of a second composite fabric material having a plurality of second fibers oriented in a second direction. Included is an apparatus comprising a soft in plane rotor comprising two longitudinal side portions connected together via two outboard portions, wherein the outboard portions comprise a plurality of first layers formed of a first composite fabric material, and a plurality of second layers formed of a second composite fabric material, wherein the soft in plane rotor yoke does not comprise any narrow steered slit tape or filament windings.

Abstract: An apparatus comprising a soft in plane rotor yoke comprising two longitudinal side portions connected together via two outboard portions, wherein the outboard portions comprise a plurality of first layers formed of a first composite fabric material having a plurality of first fibers oriented in a first direction, and a plurality of second layers formed of a second composite fabric material having a plurality of second fibers oriented in a second direction. Included is an apparatus comprising a soft in plane rotor comprising two longitudinal side portions connected together via two outboard portions, wherein the outboard portions comprise a plurality of first layers formed of a first composite fabric material, and a plurality of second layers formed of a second composite fabric material, wherein the soft in plane rotor yoke does not comprise any narrow steered slit tape or filament windings.

Abstract: A hub system comprises at least one yoke, at least one shear bearing, and at least one mast adapter. The at least one mast adapter is configured to support the at least one yoke and the at least one shear bearing, and the at least one yoke has a flapping hinge that is non-coincident with a flapping hinge of the at least one shear bearing. Another hub system comprises a stacked yoke and a mast adapter. The mast adapter is configured to transfer rotation from a rotor mast to the hub system to rotate the hub system about a central axis of rotation. The mast adapter is further configured to support the stacked yoke such that each yoke in the stacked yoke is configured to accommodate at least some amount of rotation about an axis that is perpendicular to or about perpendicular to the central axis of rotation.

Abstract: A method of repairing a core stiffened structure, including removing a damaged portion of the core stiffened structure; bonding a shelf onto a first core member; bonding a second core member to a shelf; and securing a skin patch over the second core member.

Abstract: In some embodiments, a rotor system for a rotorcraft includes a yoke, a blade, and a grip that is configured to couple the blade to the yoke. The grip has a plurality of baseline layers and a compliant layer. The baseline layers each have a plurality of fibers disposed in a first polymeric matrix. The compliant layer has a plurality of fibers disposed in a second polymeric matrix. The compliant layer is stronger than the baseline layer and the first polymeric matrix has a different chemical composition than the second polymeric matrix.

Abstract: A method of monitoring usage of a component of an aircraft can include: monitoring a usage of the component by using a torque measurement system to calculate torque events in a time period; categorizing the usage of the component by assigning a usage value based upon whether the number of torque events in the period of time is above or below a threshold; and determining a life used of the component.