Abstract: An aircraft is provided including an airframe, an extending tail, and a counter rotating, coaxial main rotor assembly including an upper rotor assembly and a lower rotor assembly. A translational thrust system positioned at the extending tail, the translational thrust system providing translational thrust to the airframe. The main rotor assembly and the translational thrust system are configured to provide hover nose down, hover nose up and hover level modes of flight.

Abstract: An aircraft is provided including an airframe, an extending tail, a counter-rotating, coaxial main rotor assembly having an upper rotor assembly and a lower rotor assembly, and a translational thrust system including a propeller positioned at the extending tail. The translational thrust system is configured to provide translational thrust to the airframe when the aircraft is in a non-autorotation state and to generate power when in an autorotation state. A gearbox interconnects the propeller and the main rotor assembly to drive the main rotor assembly and the translational thrust system in the non-autorotation state. When the aircraft is in autorotation, the power generated by the propeller drives rotation of the main rotor assembly via the gearbox.

Abstract: An aircraft is provided including an airframe, an extending tail, and a counter rotating, coaxial main rotor assembly including an upper rotor assembly composed of a plurality of blades and a lower rotor assembly composed of a plurality of blades. A translational thrust system positioned at the extending tail, the translational thrust system providing translational thrust to the airframe. A flight control system to control the upper rotor assembly and the lower rotor assembly, wherein the flight control system is configured to control lift offset of the upper rotor assembly and the lower rotor assembly.

Abstract: An aircraft is provided and includes an airframe, an extending tail, a counter rotating, coaxial main rotor assembly including an upper rotor assembly and a lower rotor assembly, a translational thrust system positioned at the extending tail, the translational thrust system providing translational thrust to the airframe, at least one sensor and at least one inertial measurement unit (IMU) to sense current flight conditions of the aircraft, an interface to execute controls of a main rotor assembly in accordance with control commands and at least one flight control computer (FCC) to issue the control commands. The at least one FCC includes a central processing unit (CPU) and a memory having logic and executable instructions stored thereon, which, when executed, cause the CPU to issue the control commands based on the current flight conditions and a result of an execution of the logic for the current flight conditions.

Abstract: A rotary-wing aircraft includes an airframe, a first rotor assembly configured to rotate about an axis and a first fairing disposed between the airframe and the first rotor assembly. A sensory system of the rotary-wing aircraft is supported by the first fairing.

Abstract: One aspect is a flight control system for a rotary wing aircraft including a main rotor system and an elevator control system. A flight control computer of the flight control system includes processing circuitry configured to execute control logic. The control logic includes an inverse plant model that produces a main rotor feed forward command based on a pitch rate command, and a load alleviation control filter configured to reduce loads on a main rotor system and produce an elevator command for an elevator control system. A transformed elevator command filter produces a main rotor pitch adjustment command based on the elevator command, and a main rotor command generator generates an augmented main rotor feed forward command for the main rotor system based on the main rotor feed forward command and the main rotor pitch adjustment command.

Abstract: Disclosed is a rotorcraft including a plurality of blades, and a control computer configured to obtain a blade bending measurement from a sensor associated with a one of the plurality of blades, process, by a device comprising a processor, the blade bending measurement to obtain moment data for the rotorcraft, obtain data from an inertial measurement unit (IMU), wherein the data obtained from the IMU pertains to at least one of a pitch of the aircraft and an angular rate, and process, by the device, the moment data and the data from the IMU to generate a command configured to stabilize the aircraft, wherein the command is based on a reference input, and wherein the reference input is based on at least one input provided by a pilot of the aircraft.

Abstract: Disclosed is a rotorcraft including a plurality of blades, and a control computer configured to obtain a blade bending measurement from a sensor associated with a one of the plurality of blades, process, by a device comprising a processor, the blade bending measurement to obtain moment data for the rotorcraft, obtain data from an inertial measurement unit (IMU), wherein the data obtained from the IMU pertains to at least one of a pitch of the aircraft and an angular rate, and process, by the device, the moment data and the data from the IMU to generate a command configured to stabilize the aircraft, wherein the command is based on a reference input, and wherein the reference input is based on at least one input provided by a pilot of the aircraft.

Abstract: Embodiments are directed to obtaining at least one measurement of blade bending associated with at least one blade of at least one rotor of an aircraft, processing, by a device comprising a processor, the at least one measurement to obtain moment data, obtaining data from an inertial measurement unit (IMU), and processing, by the device, the moment data and the data from the IMU to generate a command configured to stabilize the aircraft.

Abstract: An exhaust system for reducing infrared emissions of a rotary wing aircraft includes an exhaust duct having a fore end for connection with an aft turbine section of an engine of the rotary wing aircraft, the exhaust duct having an aft end having an exhaust opening to expel engine exhaust proximate to a tail fairing of the rotary wing aircraft; and a drive shaft collocated with the exhaust duct, the drive shaft configured to provide rotational force to an aft propeller of the rotary wing aircraft.

Abstract: A main rotor system of an aircraft is provided including a first rotor coupled to a transmission and configured to rotate about an axis in a first direction. A second rotor is similarly coupled to the transmission and is configured to rotate about the axis in a second direction. At least the first rotor includes an individual blade control system (IBCS) configured to adjust a pitch of each of a plurality of blade of the first rotor independently. A standpipe is fixedly attached to the aircraft. The standpipe is arranged such that the first rotor and the second rotor rotate relative to the standpipe. At least one slip ring is configured to transmit electrical power and/or a control signal to the at least one IBCS.

Abstract: A method of controlling a helicopter having a rotor with blades is provided. The method includes receiving, by a computing device comprising a processor, at least one input associated with the helicopter; generating, by the computing device, control signals configured to counteract blade bending associated with the rotors based on the received at least one input; measuring, by the computing device, blade signals using sensors for the blades; extracting, by the computing device, harmonic loads from the measured blade signals; adapting, by the computing device, the control signals based on the harmonic loads; and controlling, by the computing device, servos connected to the blades to adjust the blades according to the adapted control signals to reduce vibratory loads on the blades.

Abstract: Embodiments are directed to obtaining at least one measurement of blade bending associated with at least one blade of at least one rotor of an aircraft, processing, by a device comprising a processor, the at least one measurement to obtain moment data, obtaining data from an inertial measurement unit (IMU), and processing, by the device, the moment data and the data from the IMU to generate a command configured to stabilize the aircraft.

Abstract: A vibration control system includes four mass discs located at a central axis and rotatable thereabout. Each mass disc includes a mass secured thereto wherein rotation of the four mass discs creates a vibratory force output. A power transfer assembly is located between adjacent mass discs of the four mass discs and is configured to transfer rotational energy between the adjacent mass discs. The power transfer assembly includes a power transfer shaft rotatable about a power transfer shaft axis and a power transfer disc connected to the power transfer shaft and in frictional contact with each of the adjacent mass discs at a contact point. When the power transfer shaft is rotated, a radial location of the contact point at each of the adjacent mass discs relative to the central axis is changed, altering the vibratory force.

Abstract: A method of controlling a helicopter having a rotor with blades is provided. The method includes receiving, by a computing device comprising a processor, at least one input associated with the helicopter; generating, by the computing device, control signals configured to counteract blade bending associated with the rotors based on the received at least one input; measuring, by the computing device, blade signals using sensors for the blades; extracting, by the computing device, harmonic loads from the measured blade signals; adapting, by the computing device, the control signals based on the harmonic loads; and controlling, by the computing device, servos connected to the blades to adjust the blades according to the adapted control signals to reduce vibratory loads on the blades.

Abstract: A main rotor system of an aircraft is provided including a first rotor coupled to a transmission and configured to rotate about an axis in a first direction. A second rotor is similarly coupled to the transmission and is configured to rotate about the axis in a second direction. At least the first rotor includes an individual blade control system (IBCS) configured to adjust a pitch of each of a plurality of blade of the first rotor independently. At least one slip ring is configured to transmit electrical power and/or a control signal to the at least one IBCS.

Abstract: A computer-implemented method, system, and computer program product for virtual monitoring of aircraft fleet loads are provided. The method includes calculating virtual load data associated with an aircraft from a set of orthogonal waveforms. The method also includes calculating a set of coefficients as a function of parametric data and high frequency data associated with an aircraft. The method further includes storing the set of coefficients on the aircraft and transmitting the set of coefficients to a ground-based system configured to reproduce the virtual load data based on a copy of the set of orthogonal waveforms and the received set of coefficients in order to perform aircraft fleet management.

Abstract: An exhaust system for reducing infrared emissions of a rotary wing aircraft includes an exhaust duct having a fore end for connection with an aft turbine section of an engine of the rotary wing aircraft, the exhaust duct having an aft end having an exhaust opening to expel engine exhaust proximate to a tail fairing of the rotary wing aircraft; and a drive shaft collocated with the exhaust duct, the drive shaft configured to provide rotational force to an aft propeller of the rotary wing aircraft.

Abstract: A method of counteracting a rotor moment of one or more rotors of a concentric dual-rotor helicopter includes sensing angular velocity and angular acceleration of a helicopter during a flight maneuver. The angular velocity and angular acceleration are compared to a set of control parameters and one or more control servos change the cyclic pitch of the one or more rotors to counteract the rotor moment. A control system for counteracting a rotor moment of one or more rotors of a concentric dual-rotor helicopter includes one or more sensors configured to sense angular velocity and angular acceleration of a helicopter during a flight maneuver. A computer is operably connected to the one or more sensors and configured to compare sensor data to a set of control parameters. A plurality of control servos change the cyclic pitch of the one or more rotors to counteract the rotor moment.

Abstract: A vibration control system includes four mass discs located at a central axis and rotatable thereabout. Each mass disc includes a mass secured thereto wherein rotation of the four mass discs creates a vibratory force output. A power transfer assembly is located between adjacent mass discs of the four mass discs and is configured to transfer rotational energy between the adjacent mass discs. The power transfer assembly includes a power transfer shaft rotatable about a power transfer shaft axis and a power transfer disc connected to the power transfer shaft and in frictional contact with each of the adjacent mass discs at a contact point. When the power transfer shaft is rotated, a radial location of the contact point at each of the adjacent mass discs relative to the central axis is changed, altering the vibratory force.