Abstract: A method of determining structural health of an assembly includes determining a Margin of Safety (MSH) value for at least one of a plurality of components in the assembly when the assembly is healthy. The method includes determining if damage to the assembly has occurred. If damage to the assembly has occurred, the method includes determining a Margin of Safety (MSD) value for at least one of the plurality of components in the assembly when the assembly is damaged. The method includes determining a Structural Health Index (SHI) of the assembly based on the MSD value for the at least one undamaged component.

Abstract: An external hook system for a rotary-wing aircraft includes a lower frame interface which accommodates longitudinal and lateral loads and an upper frame interface. A tension member is mountable between the lower frame interface and the upper frame interface to transfer tension loads between the lower frame interface and the upper frame interface.

Abstract: An external hook system for a rotary-wing aircraft includes a lower frame interface which accommodates longitudinal and lateral loads and an upper frame interface. A tension member is mountable between the lower frame interface and the upper frame interface to transfer tension loads between the lower frame interface and the upper frame interface.

Abstract: A composite sandwich panel a first facing and a second facing over a core layer, the first and second facings having at least one fiberglass layer between an inner and an outer graphite layer.

Abstract: A composite sandwich panel a first facing and a second facing over a core layer, the first and second facings having at least one fiberglass layer between an inner and an outer graphite layer.

Abstract: A duct cover for use with a duct within a vehicle, the duct cover operative for directing a fluid flow. The duct cover being further operative for minimizing the entrance of foreign object debris into the duct. The duct cover has a flow directing honeycomb portion for conducting the passing fluid flow in a preferred direction. The flow directing honeycomb comprises an array of continuous, polygon shaped open cells which are biased with respect to the initial fluid flow direction. The periphery of the flow directing honeycomb is rigidized to stiffen the same for minimizing the displacements thereof. The rigidity is provided by a framing member comprising upper and lower skin structures affixed to a core material. The framing member is preferably adhesively bonded to the flow directing honeycomb by means of a foaming adhesive and a barrier member. The barrier member is operative for minimizing the expansion of the foaming adhesive into the open cells of the honeycomb.

Abstract: A composite sandwich structure which includes upper and lower skin structures, first and second honeycomb core structures, and an intermediate portion disposed between the first and second honeycomb core structures. The intermediate portion comprises a composite laminate, a barrier member and a foaming adhesive layer disposed between the composite laminate and the barrier member. The foaming adhesive layer is of a type designed to expand when exposed to an elevated temperature. The composite laminate and the barrier member operate to limit the expansion of the foaming adhesive layer into the open cells of the first and second honeycomb core structures. The foaming adhesive layer, upon expansion, applies pressure against the composite laminate. This pressure, acting concomitantly with the applied curing pressure and the elevated temperature, cures the laminate. Furthermore, the expansion of the foaming adhesive urges the composite laminate and the barrier member apart so as to fill any core discrepancies, i.e.

Abstract: A method of fabricating a structural member having a stiffener bead therein. Prepreg plies or layers of high tensile strength fabric are laid up on a conformable caul plate. A rubber-like plug is prefabricated to the shape of the stiffener bead and is urged into a stiffener bead cavity of the caul plate by a metal tool to sandwich the prepreg plies between the caul and the plug. The caul and the plug cooperate to cause the prepreg plies to conform to the desired shape of the stiffener bead.

Abstract: The method of fabricating a complex part made of composite material and having a plurality of panels oriented in diverse angular relationship, and utilizing a plurality of conformable cauls upon which the composite material is individually laid up and which cauls cooperate to form one of the molds used in the co-curing of the individually laid-up composite materials.

Abstract: A structural member made up of a plurality of bonded plies of high tensile strength woven fabric and molded to include at least one stiffener bead having elliptically shaped ends, and a structural part so fabricated.

Abstract: A support truss for the main rotor assembly of a helicopter is configured to structurally support the main rotor assembly in integrated combination with the helicopter airframe and to transmit dynamic and static longitudinal, lateral, vertical, and torsional loads of the main rotor assembly into the helicopter airframe at two distinct, spaced-apart load transfer levels.