Sikorsky Aircraft Corporation

Lockheed Martin Corporation

Erez Eller

Matthew T Luszcz

Kevin L Bredenbeck

Steven D Weiner

Matthew A White

Ole Wulff

John Knag

Aaron L Greenfield

Bryan S Cotton

William J Eadie

Kenneth C Arifian

William Arthur Welsh

David H Hunter

Timothy Fred Lauder

James P Cycon

Joshua David Isom

Mark W Davis

Kenneth Stephen Wittmer

Todd A Garcia

Joseph Pantalone, Iii

Cody Fegely

William P Fell

Frederick L Bourne

John S Chapkovich, Iii

Ashley DeVito

Robert K Goodman

Richard Thomas Hood

Jay Benjamin Monahan

Brian Anderson

Frederick John Miner

Joseph Pantalone Iii

Adam Leone

John S Chapkovich Iii

An aircraft includes a body having a fuselage and a wing assembly, a main shaft supported for rotation with respect to the body about a rotor axis, and a blade assembly coupled to the main shaft for corotation therewith. The blade assembly includes a rotor hub and a plurality of blades circumferentially spaced about the rotor hub. Each blade is coupled to the rotor hub for rotation about a respective blade axis. The aircraft includes a pitch control system coupled to the blade assembly to rotate each blade about the respective blade axis. The pitch control system includes a slider, a swashplate, a first actuator coupled to the slider, and a second actuator operable to rotate the swashplate assembly with respect to the slider.

Rotor control for a convertible aircraft

A method for controlling a rotary wing aircraft includes determining a measured airspeed of the rotary wing aircraft based on data from a pitot probe, determining an estimated airspeed of the rotary wing aircraft based on rotor control commands, and determining a blended airspeed based on both the measured airspeed and the estimated airspeed.

Blended airspeed technique for helicopter control at low airspeeds

An aircraft is provide 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. At least one flight control computer configured to independently control the upper rotor assembly and the lower rotor assembly through a fly-by-wire control system. A plurality of sensors to detect sensor data of at least one environmental condition and at least one aircraft state data, wherein the sensors provide the sensor data to the flight control computer.

Independent control for upper and lower rotor of a rotary wing aircraft

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. A cockpit in the airframe, the cockpit including two seats and a single collective control input positioned between the two seats.

Single collective stick for a rotary wing aircraft

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.

Dual rotor, rotary wing aircraft

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.

Gearbox for a dual rotor, rotary wing aircraft

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. A horizontal stabilizer with a left elevator and right elevator positioned at the extending tail. A flight control computer to independently control one or more of the main rotor assembly and the elevator through a fly-by-wire control system. The flight control computer is configured to mix a collective pitch of the main rotor assembly and a deflection of the elevator.

Collective to elevator mixing of a rotary wing aircraft

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.

Lift offset control of a rotary wing aircraft

A method of controlling noise of an aircraft includes storing a plurality of predefined noise modes; receiving a selection of a selected noise mode from the plurality of predefined noise modes, the selected noise mode identifying at least one operational parameter; and controlling the aircraft in response to the at least one operational parameter.

Noise modes for rotary wing aircraft

A method for controlling a differential rotor roll moment for a coaxial helicopter with rigid rotors, the method including receiving, with a processor, a signal indicative of a displacement command from a controller; receiving, with the processor via a sensor, one or more signals indicative of a longitudinal velocity, an angular velocity of one or more rotors and an air density ratio for the helicopter; determining, with the processor, a ganged collective mixing command in response to the receiving of the displacement command; determining, with the processor, a rotor advance ratio as a function of the longitudinal velocity and the angular velocity; and determining, with the processor, a corrective differential lateral cyclic command for the rigid rotors that controls the differential rotor roll moment to a desired value.

Steady state differential roll moment control with automated differential lateral control

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.

Elevator load alleviating control for a rotary wing aircraft

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.

Moment limiting control laws for dual rigid rotor helicopters

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.

Rotor moment feedback for stability augmentation

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.

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.

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Oakville, CT, United States of America

Erez Eller