Abstract: An aircraft includes a fuselage and an engine housed in the fuselage. A ram-air engine inlet is formed on an exterior of the fuselage. The ram-air engine inlet is defined, at least in part, by a cowling door. The cowling door is moveable between a closed position and an open position. An intake duct fluidly couples the ram-air engine inlet to the engine. A filter is disposed across the intake duct. A bypass duct is formed in the ram-air engine inlet aft of the intake duct. The bypass duct is operable to be selectively opened and closed.

Abstract: A hybrid rotor propulsion system includes a motor having a rotational output connected to a rotor and a prime mover connected to the motor through a rotational input, the prime mover configured to apply a rotational input speed to the motor.

Abstract: A line-replaceable thrust module includes a nacelle configured to be mechanically connected to an anchoring location of an unmanned aerial vehicle (UAV), an electric motor coupled to the nacelle, an electric speed controller configured to control the speed of the electric motor and configured to be electrically connected to a communication network of the UAV, and a fuel cell system configured to produce electrical energy from an electrochemical reaction between hydrogen and oxygen. The fuel cell system includes a fuel cell, a hydrogen tank, a pressure regulator coupled to the hydrogen tank, and a supply line coupled between the pressure regulator and the fuel cell.

Abstract: A thermally conductive curing process adds conductive additives to create pathways for dissipating heat during a curing process, thereby reducing the cure time, increasing the output capability, and reducing cost. Conductive particles or short fibers can be dispersed throughout the resin system or composite fiber layers in pre-impregnated or RTM-processed composite material. By disposing conductive particles or short fibers in a resin as part of the curing process, heat generated during the curing process can dissipate more quickly from any type of composite, especially thick composites. Conductive additive examples include multi-walled carbon nanotubes (MWCNTs), single-walled carbon nanotubes (SWCNTs), graphene/graphite powder, buckyballs, short fibrous particulate, nano-clays, nano-particles, and other suitable materials.

Abstract: An exemplary rotorcraft includes a power train with an engine coupled to a gearbox, a main rotor blade having a mast coupled to the power train, a control input linkage in communication between a pilot input device and the main rotor blade configured to communicate a control input force from the pilot input device to the main rotor blade, and a counterweight system in connection with the control input linkage and the power train to apply a centrifugal force to the control input linkage.

Abstract: An ice-management method for an aircraft includes scavenging torque from a mast of the aircraft with a system that is configured to provide an ice-management capability. The method includes using the scavenged torque to impart a vibratory force to an arm of the system and imparting the vibratory force from the arm to an inner surface of a spinner of the aircraft via a contact of the arm.

Abstract: A method of controlling a tail rotor system of a helicopter includes pivoting a swashplate of the tail rotor system about an axis passing through a diameter of the swashplate. Pivoting the swashplate causes a first linkage of a first pair of linkages coupled between the swashplate and a collective crosshead to move in a first direction and a second linkage of the first pair of linkages coupled between the swashplate and the collective crosshead to move in a second direction that is opposite the first direction. The movement of the first and second linkages causes a plane of rotation of a pair of rotors of the tail rotor system to cant relative to a centerline of a mast of the tail rotor system.

Abstract: A method for generating a simulation model to evaluate a flight control system including determining at least one high level requirement for an aircraft flight system during a non-automated engineering process; generating at least one specification of the high level requirement; generating a model computer-readable program code based on the at least one specification; executing the model computer-readable program code to generate a model code unit; executing the model code unit to generate a procedure document; executing the model code unit to perform a simulation method to generate a bench test computer-readable program code: executing the bench test computer-readable program code on a bench test computing device to generate a simulation output; and comparing the simulation output to the at least one specification of the high level requirement to generate a pass or fail result.

Abstract: A detachable cargo mirror assembly for use on a rotorcraft surface that includes a bracket configured to mount to a surface on the rotorcraft, the bracket comprising a base portion and a retainer portion having a first pair of opposing holes, an elongated arm having two opposing ends, a first end for coupling with the bracket and a second end coupled to a mirror apparatus, the first end having a passage: and a releasable connector configured to engage with the first pair of opposing holes and the passage in the elongated arm when the elongated arm is in a first position to display a desired image on the mirror apparatus. The detachable cargo mirror assembly can be removed or in a stowed position when not in use.

Abstract: A rotor system for an aircraft including a driving member; an externally driven rim configured to be rotated by the driving member; a hub having a hub axis, the hub including a rotatable housing and a non-rotatable housing; a plurality of rotor blade assemblies rotatably coupled to the rotatable housing of the hub and the externally driven rim such that rotation of the externally driven rim rotates the plurality of rotor blade assemblies about the hub axis, each rotor blade assembly having a rotor blade rotatable about a respective pitch change axis; and a pitch control mechanism operably associated with the hub and the plurality of rotor blade assemblies, wherein, actuation of the pitch control mechanism rotates each rotor blade assembly about the respective pitch change axis to collectively control the pitch of the rotor blade, thereby generating a variable thrust output. Also, a method of operating the rotor system.

Abstract: An example of a hub for a tail rotor includes a body configured to couple to a mast of a rotor system, a trunnion disposed within the body, first and second shafts disposed on opposite sides of the trunnion, first and second end plates secured to the body, and first and second end bearings, the first end bearing disposed between the first shaft and the first end plate and the second end bearing disposed between the second shaft and the second end plate.

Abstract: Systems and methods include providing an aircraft with a ducted rotor assembly. The ducted rotor assembly includes a housing having a duct, a rotor drive mechanism coupled to a rotor system, and a plurality of stators that both structurally support the rotor drive mechanism within the duct of the housing and carry a fluid through internal fluid passages in the plurality of stators to provide cooling to the rotor drive mechanism. Some of the stators carry fluid to the rotor drive mechanism, where the fluid absorbs heat from the rotor drive mechanism, and some of the stators carry fluid away from the rotor drive mechanism. The rotor system generates an airflow over the stators carrying fluid away from the rotor drive mechanism to effect transfer between the fluid and the airflow.

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: The present invention achieves technical advantages as an engine compartment drainage system that allows fluid on an engine deck to exit an engine compartment, while shielding fluid from airflow. A fluid drainage apparatus utilizes a funnel member to direct fluid to an external drain line. A drain shield circumscribes the top end of the funnel member and upwardly extending therefrom and directs airflow away from the funnel member. A plurality of deck holes are disposed in the drain shield, such that fluid on the deck can enter the funnel member and exit the engine compartment. A fluid drainage system, disposes the fluid drainage apparatus in an engine deck to allow fluid on the deck to enter a funnel member of the apparatus and direct it toward the external drain line.

Abstract: In a first aspect, there is a personal air vehicle including a body having a forward portion, a central portion and an aft portion; a first ducted fan supported by the forward portion of the body; a second ducted fan supported by the aft portion of the body; and third and fourth ducted fans supported by the left and right sides of the body and pivotable relative to the body. An aspect provides a method of flying the personal air vehicle.

Abstract: A yaw control system for a rotorcraft featuring a floor mounted pair of pedals configured to measure an up and down motion of a pair of pedals and utilize that up and down motion as a yaw moment control input. The pair of pedals can rock laterally, fore and aft, or vertically. The pair of pedals can be mechanically interconnected to other pairs of pedals or electrically interconnected to duplicate motion across pairs of pedals.

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.