Abstract: A thermal management system includes a plurality of passages through a leading edge of a component of an aircraft. The thermal management system is configured to circulate coolant from a heat source through the plurality of passages in order to maximize heat transfer from the coolant to the airflow passing over the leading edge.

Abstract: A fuel-cell system at 540 VDC for powering an electrical load of a rotorcraft with a first fuel cell and a second fuel cell. Each fuel cell is configured identically and features a positive electrical node and a negative electrical node. Each fuel cell is configured to provide one half of the electrical load of the rotorcraft and one half of the voltage of the electrical load.

Abstract: A stack fuel cell array featuring paired fuel-cell systems combined to generate 540 VDC for a rotorcraft. Power from the hydrogen-based fuel cells is provided to the rotorcraft. A rated electrical load of the rotorcraft helps determine how many paired fuel-cell systems are needed during any fuel-cell systems failures. Each of the paired fuel-cell systems is coupled to an electrical load of the rotorcraft. The system detects any fuel cell failures and removes other working fuel cells as needed to balance the electrical system.

Abstract: A rotorcraft featuring a fuselage, a forward fuselage ducted fan located in the fuselage, and an aft fuselage ducted fan located in the fuselage. The rotorcraft is directly powered by electricity and can be supplemented with additional powers sources. Two sets of pivoting ducted fans provide additional lift and thrust as needed to control the rotorcraft.

Abstract: A composite assembly has an outer spar component having an outer spar component inner profile, an inner spar component having an inner spar component outer profile substantially complementary to the outer spar component inner profile, and an adhesive disposed between the outer spar component and the inner spar component.

Abstract: One example of a cowling assembly for a rotorcraft includes a stationary fairing affixed to an airframe of the rotorcraft, an articulated fairing hinged on the stationary fairing for articulation relative to the stationary fairing between a closed position, a first partially open maintenance position and a second fully open maintenance position. The articulated fairing is supported in the first maintenance position by a for example gas-charged strut and is releasably locked in the second maintenance position against the stationary fairing by a locking mechanism. The locking mechanism includes a latch blade disposed on the stationary fairing and a latch arranged on the articulated fairing, wherein a latch pin engages with a hole or recess in the latch blade when the latch blade extends through a slot in the articulated fairing.

Abstract: A nose assembly of an aircraft includes a nose airframe having a nonhorizontal mounting surface and a turret assembly mounted on the nonhorizontal mounting surface. The turret assembly includes a turret device housing rotatable relative to the nonhorizontal mounting surface. The nose airframe includes a nose skin forming a nose fairing having an apex aperture. The nose skin at least partially covers the turret assembly such that the turret assembly is at least partially inset in the apex aperture of the nose fairing.

Abstract: An exemplary convertible engine includes an engine housing forming a fan duct extending from a fan inlet to an exhaust; a fan positioned in the fan duct proximate the fan inlet; an engine core located in the fan duct aft of the fan, the engine core coupled to the fan by a fan shaft; a drive shaft mechanically coupled to the engine core and extending exterior of the engine housing; and a dedicated core inflow duct coupled to the core and having a core inlet to capture and direct air into the engine core. An inlet barrier filter may be located in the dedicated core inflow duct. The core inlet may be located inside of the fan duct or exterior to the fan duct. A gearbox may be operationally connected to the fan shaft and may be located inside of the fan duct.

Abstract: A gas-leak management system including a primary duct; and a leak-management duct, at least a portion of the leak-management duct surrounding at least a portion of the primary duct, wherein the leak-management duct includes a gap between the portion of the primary duct and the portion of the leak-management duct, and including one or more vent holes in fluid communication with the gap.

Abstract: An intentionally activated frangible bonding system comprises a frangible adhesive, adhesive primer, composite material matrix, and/or the like, having a polydispersion of at least one additive spread throughout the frangible bonding material. The additive degrades a bond provided by the frangible bonding material, upon application of a specific energy to the frangible bonding material. An energy emitter is configured to selectively direct the specific energy toward a structure or assembly comprising components bonded by the frangible bonding material to degrade the frangible bonding material bonding the components for disassembly.

Abstract: A modal tailboom flight control system for a compound helicopter is operable in a plurality of modes including a forward thrust mode and an anti-torque mode. The modal tailboom flight control system includes a tailboom, a drivetrain extending through the tailboom, an anti-torque system coupled to the drivetrain and rotatable to generate anti-torque thrust for the compound helicopter in the anti-torque mode and a pusher propeller coupled to the drivetrain and rotatable to generate forward thrust for the compound helicopter in the forward thrust mode. The pusher propeller is positioned forward of the anti-torque system.

Abstract: A spar assembly has a spar having a tip comprising a most outboard portion of the spar, a root comprising a most inboard portion of the spar, a main section disposed inboard relative to the tip, and a middle section disposed inboard relative to the main section. The spar also has a transition section disposed between the main section and the middle section and the transition section has an outboard interface cross-sectional shape and an inboard cross-sectional shape that is different than the outboard interface cross-sectional shape.

Abstract: A tandem tiltrotor aircraft in which the tiltrotor assemblies are operably coupled at the forward and aft ends of the fuselage of the aircraft is disclosed. The tiltrotor assemblies are capable of rotating between a vertical lift position and a horizontal flight position. The in-line location of the tiltrotor assemblies allow the aircraft to have the vertical take-off and landing capabilities, and, in combination with the at least one wing, can be used in horizontal flight. The nacelles can be disposed on the fuselage they are coaxial in forward flight and do not add to the drag profile like wing-tip nacelles would. When wing-borne flight is desired some or all of the rotors can rotate down so the thrust vector is in a generally horizontal plane.

Abstract: A rotor system is provided in one example embodiment and may include a first pair of rotor blades comprising a first pitch and a first diameter; and a second pair of rotor blades comprising a second pitch and a second diameter, wherein the first pitch of the first pair of rotor blades and the second pitch of the second pair of rotor blades are different.

Abstract: A rotor assembly for use in an aircraft comprising has a rotor hub, a spinner structure comprising a spinner opening, and a rotor blade received through the spinner opening. The rotor blade has a rotor root located proximate to the rotor hub. The rotor assembly also has a motive fairing face that at least partially rests along the rotor hub.

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 removable passive airflow oscillation device can be disposed within a pressurized wing structure utilized as a plenum. The passive airflow oscillation device can be a removable insert disposed into exterior vehicle surfaces with pressurization of a sealed chamber to provide the airflow. The device can include a cavity configured to receive the airflow from an ingress opening, direct the airflow therethrough to generate a predetermined oscillating airflow, and expel the oscillatory airflow from the egress opening. The removable passive airflow oscillation devices can provide quick and simple replacement and maintenance of damaged or clogged devices. The aft chamber of the flap seal can be sealed and pressurized to serve as a plenum providing the airflow to the actuators. The device can receive airflow, such as compressor air, and expel an oscillating airflow. Because each device is self-contained the number of devices and location thereof can vary by application.

Abstract: A dynamic rotor-phasing unit can phase rotors in-flight for dynamic rotor tuning and in an idle state for aircraft storage. The input and output shafts can be clocked (e.g., rotated) from 0 degrees apart to in excess of 360 degrees apart or from 0 degrees apart to 140 degrees apart. Such rotation can minimize the footprint of an aircraft for stowing purposes, as the rotor blades can be folded to fit within a smaller area without disconnecting the drive system. Additionally, the unit can allow tiltrotor blades to be clocked during flight, which can allow the live-tuning of the aircraft's rotor dynamics. A fail-safe rotary actuator can rotate a stationary planet carrier to clock the input shaft and the output shaft. Alternatively, an actuator can position a slider housing to clock the input shaft and the output shaft.

Abstract: A ducted fan assembly has a central axis, a duct having an outer wall and an inner wall, a fan hub at least partially disposed on the central axis, a plurality of fan blades coupled to the fan hub, and a first stator. The first stator has a first end coupled to the inner wall, a second end coupled to the inner wall, and a hub interface disposed between the first end and the second end, wherein the hub interface is coupled to the fan hub.