Abstract: A vibration attenuator for a rotor is rotatable about a mast axis and has a frame configured for rotation about the mast axis relative to the rotor. A first mass is axially translatable in a first direction relative to the frame parallel to a first axis, and a first biasing force urges the first mass toward a first-mass rest position in which the first mass is symmetric about the mast axis. A second mass is axially translatable in a second direction relative to the frame parallel to a second axis, and a second biasing force urges the second mass toward a second-mass rest position in which the second mass is symmetric about the mast axis. A selected first or second mass moves radially outward from the rest position to oppose vibrations in the rotor.

Abstract: A vibration attenuation system for attenuating vibrations in a mast of an aircraft includes a weight attached to the mast but free to orbit about the mast. The weight can be comprised of one or more weight assemblies. Embodiments can include a single weight, or plural weight assemblies wherein each weight assembly can include a mechanical interconnecting mechanism so that each weight assembly receives feedback regarding the position and movement of one or more other weight assemblies. Each weight can be associated with a spring that urges the weight towards a neutral position. Rotation of the mast can cause the weight to orbit about the mast and self-excite such that the weight acts against the urging of the spring towards an attenuating position.

Abstract: An aircraft comprises a fuselage, one or more support structures connected to the fuselage, one or more engines or motors disposed within or attached to the one or more support structures or the fuselage, and a distributed propulsion system. The distributed propulsion system comprising two or more propellers symmetrically distributed in an array along the one or more support structures with respect to a center of gravity of the aircraft and operably connected to the one or more engines or motors, wherein each propeller has a rotation direction within a tilted plane of rotation, and a summation of horizontal force vectors created by the tilted plane of rotation of all the propellers is substantially zero when all the propellers are creating a substantially equal thrust magnitude. Movement of the aircraft is controlled by selectively increasing or decreasing a thrust of at least one of the two or more propellers.

Abstract: In some examples, an aircraft comprises an airframe, a rotor system coupled to the airframe, and a vibration attenuation system. The rotor system is operable to exert a vibratory force on the airframe. The vibration attenuation system comprises two or more batteries and elastic devices. The two or more batteries are operable to supply power to the rotor system. The elastic devices coupled to the two or more batteries and the airframe. The elastic devices are configured to attenuate the vibratory force based on facilitating oscillation of the two or more batteries. In other examples, a method comprises coupling elastic devices to two or more batteries and an airframe of an aircraft. The elastic devices receiving a vibratory force via the airframe and attenuate the vibratory force based on facilitating oscillation of the two or more batteries.

Abstract: A vibration attenuation system for attenuating vibrations in a mast of an aircraft includes a weight attached to the mast but free to orbit about the mast. The weight can be comprised of one or more weight assemblies. Embodiments can include a single weight, or plural weight assemblies wherein each weight assembly can include a mechanical interconnecting mechanism so that each weight assembly receives feedback regarding the position and movement of one or more other weight assemblies. Each weight can be associated with a spring that urges the weight towards a neutral position. Rotation of the mast can cause the weight to orbit about the mast and self-excite such that the weight acts against the urging of the spring towards an attenuating position.

Abstract: An anti-tail buffet device leverages existing rotorcraft components to attenuate a tailboom's lateral “ringing” from air buffeting. Anti-buffet masses are tuned to the tailboom's lateral-bending or torsional natural frequency such that when lateral motion occurs, the response at this frequency is cancelled by the anti-buffet system, preventing this vibration from entering into the tailboom structure. Motion stops prevent over-travel. The mass of the tail rotor actuator is soft-mounted, such that its natural frequency is equal to the tailboom's lateral-bending or torsional natural frequency. When lateral loading occurs on the tail rotor disk, the lateral response at this frequency is attenuated by the soft-mounted tail rotor actuator, thereby preventing the vibration in the tailboom structure.

Abstract: A method of increasing a stability speed of a tiltrotor aircraft includes pivoting a rotor assembly having at least three rotor blades from a first position for operating the tiltrotor aircraft in a helicopter mode to a second position for operating the tiltrotor aircraft in an airplane mode, and increasing a stiffness of the rotor assembly when the rotor assembly is in the second position.

Abstract: In an implementation, the compound helicopter may include at least one rotary wing system, at least one first power generator and at least one second power generator. The at least one first power generator may rotate the at least one rotary wing blade to provide lift and a primary thrust force in a first direction to the helicopter. The at least one second power generator may be connected to the helicopter and may provide lift and a secondary thrust force in a direction that is independent of a direction of the primary thrust force and may also provide a secondary thrust force in a direction that is substantially parallel to the primary thrust force.

Abstract: An electric reaction control system that can selectively expel a “burst” or “puff” of air to alter the orientation of the aircraft during flight. An aircraft incorporating ducting, an air compressor, an electric motor, and a plurality of nozzles can facilitate in-flight trajectory modifications. When an air burst is needed to provide thrust for the purposes of reaction control, nozzles are selectively opened and closed to provide roll, pitch, and yaw of the aircraft. The ERCS can facilitate an electric aircraft that would be very agile and very light, utilizing electric power, as opposed to jet power.

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 an outer skin and a damping sublayer, the damping sublayer interposed between the outer skin and the wing airframe core assembly. The tiltrotor aircraft includes a pylon assembly subject to aeroelastic movement during forward flight. The wing is subject to deflection in response to the aeroelastic movement of the pylon assembly. The damping sublayer reduces the deflection of the wing, thereby stabilizing the wing during forward flight.

Abstract: An injection system, including an injector having a dispensing mechanism configured to dispense a medicament, and a ready-to-use indicator. The ready-to-use indicator includes a controller configured to interact with the ready-to-use indicator and an audio and/or visual indicator, a temperature sensor, and a temperature analog having similar thermodynamic properties of the medicament. The temperature sensor is configured to detect a temperature of the temperature analog which represents the dynamic temperature of medicament as the medicament is heated or cooled. The temperature sensor is configured to communicate the detected temperature to the controller and to alert the controller when a preset temperature is reached. The ready-to-use indicator is configured to alert a user when the preset temperature is reached, signifying the medicament is thermally ready to be delivered by the dispensing mechanism. The audio and/or visual indicator is configured to display indicate one or more notifications to the user.

Abstract: An aircraft having a differential rotor speed resonance avoidance system. The aircraft includes an airframe having structural elements subject to resonant vibration at critical frequencies. A thrust array is coupled to the airframe. The thrust array includes at least four rotor systems distributed about the airframe, each rotor system operable over a range of rotor speeds. A flight control system is operably associated with the thrust array and is configured to independently control the rotor speed of each rotor system. While preserving flight dynamics during flight operations, the flight control system selectively increases the rotor speed of some of the rotor systems by a speed delta and decreases the rotor speed of others of the rotor systems by the speed delta to avoid generating excitation frequencies by the rotor systems at the critical frequencies.

Abstract: An electric reaction control system that can selectively expel a “burst” or “puff” of air to alter the orientation of the aircraft during flight. An aircraft incorporating ducting, an air compressor, an electric motor, and a plurality of nozzles can facilitate in-flight trajectory modifications. When an air burst is needed to provide thrust for the purposes of reaction control, nozzles are selectively opened and closed to provide roll, pitch, and yaw of the aircraft. The ERCS can facilitate an electric aircraft that would be very agile and very light, utilizing electric power, as opposed to jet power.

Abstract: According to one implementation of the present disclosure, a tail rotor system of a rotorcraft includes an electric motor, a swiveling actuator, a spindle, and a hub assembly. The hub assembly may be configured to position two or more blades. Also, in response to a control signal, the swiveling actuator may be configured to actuate swivel rotation of the spindle around a vertical axis such that the hub assembly turns from a first horizontal directional axis to a second horizontal directional axis.

Abstract: A soft-in-plane proprotor system for a tiltrotor aircraft having a helicopter mode and an airplane mode. The proprotor system includes a hub, a plurality of proprotor blades and a plurality of blade support assemblies coupling the proprotor blades with the hub. Each blade support assembly includes a flapping bearing coupled to the hub and a yoke having first and second longitudinal sections with outboard grip members and an inboard arcuate section connecting the first and second longitudinal sections and coupled to the flapping bearing. A lead-lag damper is coupled between the hub and an inboard station of the respective proprotor blade. A twist shank is coupled between the outboard grip members of the yoke and an outboard station of the respective the proprotor blade. The twist shank defines a virtual lead-lag hinge outboard of the yoke and coincident with the respective pitch change axis.

Abstract: An injection system, including an injector having a dispensing mechanism configured to dispense a medicament, and a ready-to-use indicator. The ready-to-use indicator includes a controller configured to interact with the ready-to-use indicator and an audio and/or visual indicator, a temperature sensor, and a temperature analog having similar thermodynamic properties of the medicament. The temperature sensor is configured to detect a temperature of the temperature analog which represents the dynamic temperature of medicament as the medicament is heated or cooled. The temperature sensor is configured to communicate the detected temperature to the controller and to alert the controller when a preset temperature is reached. The ready-to-use indicator is configured to alert a user when the preset temperature is reached, signifying the medicament is thermally ready to be delivered by the dispensing mechanism. The audio and/or visual indicator is configured to display indicate one or more notifications to the user.

Abstract: In some examples, an aircraft comprises an airframe, a rotor system coupled to the airframe, and a vibration attenuation system. The rotor system is operable to exert a vibratory force on the airframe. The vibration attenuation system comprises two or more batteries and elastic devices. The two or more batteries are operable to supply power to the rotor system. The elastic devices coupled to the two or more batteries and the airframe. The elastic devices are configured to attenuate the vibratory force based on facilitating oscillation of the two or more batteries. In other examples, a method comprises coupling elastic devices to two or more batteries and an airframe of an aircraft. The elastic devices receiving a vibratory force via the airframe and attenuate the vibratory force based on facilitating oscillation of the two or more batteries.

Abstract: A vibration attenuation system for attenuating vibrations in a mast of an aircraft includes a weight attached to the mast but free to orbit about the mast. The weight can be comprised of one or more weight assemblies. Embodiments can include a single weight, or plural weight assemblies wherein each weight assembly can include a mechanical interconnecting mechanism so that each weight assembly receives feedback regarding the position and movement of one or more other weight assemblies. Each weight can be associated with a spring that urges the weight towards a neutral position. Rotation of the mast can cause the weight to orbit about the mast and self-excite such that the weight acts against the urging of the spring towards an attenuating position.

Abstract: In at least one embodiment, an apparatus for generating virtual venues in a listening room in a vehicle is provided. The apparatus includes a vehicle audio controller configured to receive an incoming audio signal including entertainment data from an audio source for playback and to receive at least one captured audio signal from at least one microphone positioned in the listening room of the vehicle. The vehicle audio controller is further configured to receive a control signal indicative of a desired venue to playback the entertainment data and to adjust reverberation of at least one of the incoming audio signal and the at least one captured audio signal to playback the entertainment data in the desired venue.

Abstract: An electric reaction control system that can selectively expel a “burst” or “puff” of air to alter the orientation of the aircraft during flight. An aircraft incorporating ducting, an air compressor, an electric motor, and a plurality of nozzles can facilitate in-flight trajectory modifications. When an air burst is needed to provide thrust for the purposes of reaction control, nozzles are selectively opened and closed to provide roll, pitch, and yaw of the aircraft. The ERCS can facilitate an electric aircraft that would be very agile and very light, utilizing electric power, as opposed to jet power.