Abstract: In one aspect, there is a composite skin for a tiltrotor aircraft including a first skin having a periphery defined by a forward edge, an aft edge, and outboard ends; a second skin; and a honeycomb core disposed between the first skin and the second skin, the honeycomb core comprised of a plurality of honeycomb panels positioned along the longitudinal axis of the first skin, the plurality of honeycomb panels having an array of large cells, each cell having a width of at least 1 cm; wherein the second skin and the honeycomb core have an outer perimeter within the periphery of the first skin.

Abstract: A compliant tail structure for a rotorcraft having rotating components and a fuselage. The tail structure includes a tail assembly having first and second oppositely disposed tail members. A tail joint connects the tail assembly to an aft portion of the fuselage. The tail joint includes at least four tail mounts configured to establish a nodding axis for the tail assembly. At least two of the tail mounts are resilient tail mounts that are configured to establish a nodding degree of freedom for the tail assembly relative to the fuselage about the nodding axis, thereby detuning dynamic fuselage responses from excitation frequencies generated by the rotating components.

Abstract: A compliant tail structure for a rotorcraft having rotating components and a fuselage. The tail structure includes a tail assembly having first and second oppositely disposed tail members. A tail joint connects the tail assembly to an aft portion of the fuselage. The tail joint includes at least four tail mounts configured to establish a nodding axis for the tail assembly. At least two of the tail mounts are resilient tail mounts that are configured to establish a nodding degree of freedom for the tail assembly relative to the fuselage about the nodding axis, thereby detuning dynamic fuselage responses from excitation frequencies generated by the rotating components.

Abstract: A compliant tail structure for a rotorcraft having rotating components and a fuselage. The tail structure includes a tail assembly having first and second oppositely disposed tail members. A tail joint connects the tail assembly to an aft portion of the fuselage. The tail joint includes at least four tail mounts configured to establish a nodding axis for the tail assembly. At least two of the tail mounts are resilient tail mounts that are configured to establish a nodding degree of freedom for the tail assembly relative to the fuselage about the nodding axis, thereby detuning dynamic fuselage responses from excitation frequencies generated by the rotating components.

Abstract: A propulsion and lift system of a tiltrotor aircraft includes a wing having an outboard end, a wing tip assembly having an inboard end, a fixed nacelle coupled to the wing tip assembly and a wing-nacelle splice assembly having inboard and outboard sides. The inboard side of the wing-nacelle splice assembly is coupled to the outboard end of the wing, and the outboard side of the wing-nacelle splice assembly is coupled to the inboard end of the wing tip assembly, thereby coupling the fixed nacelle to the wing.

Abstract: A compliant tail structure for a rotorcraft having rotating components and a fuselage. The tail structure includes a tail assembly having first and second oppositely disposed tail members. A tail joint connects the tail assembly to an aft portion of the fuselage. The tail joint includes at least four tail mounts configured to establish a nodding axis for the tail assembly. At least two of the tail mounts are resilient tail mounts that are configured to establish a nodding degree of freedom for the tail assembly relative to the fuselage about the nodding axis, thereby detuning dynamic fuselage responses from excitation frequencies generated by the rotating components.

Abstract: In one aspect, there is a composite skin for a tiltrotor aircraft including a first skin having a periphery defined by a forward edge, an aft edge, and outboard ends; a second skin; and a honeycomb core disposed between the first skin and the second skin, the honeycomb core comprised of a plurality of honeycomb panels positioned along the longitudinal axis of the first skin, the plurality of honeycomb panels having an array of large cells, each cell having a width of at least 1 cm; wherein the second skin and the honeycomb core have an outer perimeter within the periphery of the first skin.

Abstract: In one aspect, there is a method of making a composite skin for a tiltrotor aircraft including providing a first skin in a mold, the first skin having a periphery defined by a forward edge, an aft edge, and outboard ends; providing a plurality of honeycomb panels having an array of large cells onto the first skin, each cell having a width of at least 1 cm; assembling the plurality of honeycomb panels along the longitudinal axis of the first skin to form a honeycomb core having an outer perimeter within the periphery of the first skin; positioning a second skin onto the honeycomb core, the second skin having an outer perimeter within the periphery of the first skin; and curing an adhesive to create a bond between the first skin, the honeycomb core, and the second skin to form a composite skin.

Abstract: In one aspect, there is a method of making a pre-cured laminate having a total number of plies in a mold, the mold having a cavity with a periphery defined by a forward edge, an aft edge, and outboard ends. The method includes selecting a first plurality of resin impregnated plies that continuously extend beyond the periphery of the cavity, the first plurality of resin impregnated plies includes at least 50 percent of the total number of plies; laying the plies in a mold; compacting the plies in a mold; and pre-curing the plies to form a pre-cured laminate, which can extend beyond the periphery of the cavity. In an embodiment, a pre-cured laminate includes a first plurality of resin impregnated plies that continuously extend beyond the periphery of the cavity.

Abstract: An airframe for a tiltrotor aircraft includes a wing airframe including a rib, a fuselage airframe including a fore-aft overhead beam and a cradle support assembly. The cradle support assembly includes a forward wing support coupled to the fore-aft overhead beam and the wing airframe and an aft wing support coupled to the fore-aft overhead beam and the wing airframe. The rib, the fore-aft overhead beam, the forward wing support and the aft wing support are substantially aligned to form a wing-fuselage integrated airframe beam assembly to support the wing airframe.

Abstract: A propulsion and lift system of a tiltrotor aircraft includes a wing having an outboard end, a wing tip assembly having an inboard end, a fixed nacelle coupled to the wing tip assembly and a wing-nacelle splice assembly having inboard and outboard sides. The inboard side of the wing-nacelle splice assembly is coupled to the outboard end of the wing, and the outboard side of the wing-nacelle splice assembly is coupled to the inboard end of the wing tip assembly, thereby coupling the fixed nacelle to the wing.

Abstract: A wing airframe for a wing of a tiltrotor aircraft includes a wing airframe core assembly and a wing skin assembly disposed on the wing airframe core assembly. The wing skin assembly includes a lower wing skin assembly disposed on the bottom side of the wing airframe core assembly. The tiltrotor aircraft includes a fuselage underneath the wing. The lower wing skin assembly has one or more buckle zones outboard of the fuselage. The buckle zones are locally susceptible to buckling in response to an impact of the tiltrotor aircraft, thereby protecting the fuselage from being crushed by the wing.

Abstract: A propulsion and lift system of a tiltrotor aircraft includes a wing having an outboard end, a wing tip assembly having an inboard end, a fixed nacelle coupled to the wing tip assembly and a wing-nacelle splice assembly having inboard and outboard sides. The inboard side of the wing-nacelle splice assembly is coupled to the outboard end of the wing, and the outboard side of the wing-nacelle splice assembly is coupled to the inboard end of the wing tip assembly, thereby coupling the fixed nacelle to the wing.

Abstract: In one aspect, there is a method of making a pre-cured laminate having a total number of plies in a mold, the mold having a periphery defined by a forward edge, an aft edge, and outboard ends. The method includes selecting a first plurality of resin impregnated plies that continuously extend beyond the periphery of the mold, the first plurality of resin impregnated plies includes at least 50 percent of the total number of plies; laying the plies in a mold; compacting the plies in a mold; and pre-curing the plies to form a pre-cured laminate, which can extend beyond the periphery of the mold. In an embodiment, a pre-cured laminate includes a first plurality of resin impregnated plies that continuously extend beyond the periphery of the mold, the first plurality of resin impregnated plies includes at least 50 percent of the total number of plies.

Abstract: A fuel system for an aircraft includes a fuel cell having a plurality of sides including a first side and at least one deformable clip having a secured end and a free end. The secured end is coupled to the first side of the fuel cell and the free end overlapping the airframe of the aircraft such that the first side of the fuel cell is positioned adjacent to the airframe. The at least one deformable clip is deformable to allow the fuel cell to move independently of the airframe in response to an impact of the aircraft, thereby protecting the fuel cell from damage resulting from the impact.

Abstract: In one aspect, there is a method of making a pre-cured laminate having a total number of plies in a mold, the mold having a cavity with a periphery defined by a forward edge, an aft edge, and outboard ends. The method includes selecting a first plurality of resin impregnated plies that continuously extend beyond the periphery of the cavity, the first plurality of resin impregnated plies includes at least 50 percent of the total number of plies; laying the plies in a mold; compacting the plies in a mold; and pre-curing the plies to form a pre-cured laminate, which can extend beyond the periphery of the cavity. In an embodiment, a pre-cured laminate includes a first plurality of resin impregnated plies that continuously extend beyond the periphery of the cavity.

Abstract: A propulsion and lift system of a tiltrotor aircraft includes a wing having an outboard end, a wing tip assembly having an inboard end, a fixed nacelle coupled to the wing tip assembly and a wing-nacelle splice assembly having inboard and outboard sides. The inboard side of the wing-nacelle splice assembly is coupled to the outboard end of the wing, and the outboard side of the wing-nacelle splice assembly is coupled to the inboard end of the wing tip assembly, thereby coupling the fixed nacelle to the wing.

Abstract: An airframe for a tiltrotor aircraft includes a wing airframe including a rib, a fuselage airframe including a fore-aft overhead beam and a cradle support assembly. The cradle support assembly includes a forward wing support coupled to the fore-aft overhead beam and the wing airframe and an aft wing support coupled to the fore-aft overhead beam and the wing airframe. The rib, the fore-aft overhead beam, the forward wing support and the aft wing support are substantially aligned to form a wing-fuselage integrated airframe beam assembly to support the wing airframe.

Abstract: A wing airframe for a wing of a tiltrotor aircraft includes a wing airframe core assembly and a wing skin assembly disposed on the wing airframe core assembly. The wing skin assembly includes a lower wing skin assembly disposed on the bottom side of the wing airframe core assembly. The tiltrotor aircraft includes a fuselage underneath the wing. The lower wing skin assembly has one or more buckle zones outboard of the fuselage. The buckle zones are locally susceptible to buckling in response to an impact of the tiltrotor aircraft, thereby protecting the fuselage from being crushed by the wing.

Abstract: A fuel system for an aircraft includes a fuel cell having a plurality of sides including a first side and at least one deformable clip having a secured end and a free end. The secured end is coupled to the first side of the fuel cell and the free end overlapping the airframe of the aircraft such that the first side of the fuel cell is positioned adjacent to the airframe. The at least one deformable clip is deformable to allow the fuel cell to move independently of the airframe in response to an impact of the aircraft, thereby protecting the fuel cell from damage resulting from the impact.