Sikorsky Aircraft Corporation

Matthew A White

Matthew T Luszcz

Erez Eller

Aaron L Greenfield

Vineet Sahasrabudhe

Kenneth Stephen Wittmer

Ole Wulff

Kevin L Bredenbeck

William P Fell

Aaron Kellner

Patrick J Dempsey

Joshua King

David H Hunter

Harshad S Sane

William C Fell, Jr

Stella Jang

Leonard M Wengler, Iii

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

A method of automating entry of an aircraft into autorotation includes detecting a loss of engine power, analyzing a sensed height and sensed airspeed of the aircraft, determining an adjusted position of one or more control surfaces of the aircraft in response to the sensed height and sensed airspeed, and automatically moving the one or more control surfaces to the adjusted position.

Automated autorotation and pilot aiding system

A method of controlling rotor moments includes receiving, in a flight control computer (FCC) a rotor moment reference value based on pilot inceptor inputs, sensing rotor moment from one or more sensors, receiving, in the FCC, a rotary wing aircraft condition parameter, and establishing, through the FCC, a rotor blade pitch angle for one or more of a plurality of rotor blades that counteracts external forces acting upon the rotary wing aircraft.

Rotor moment control system for 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 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

A fly-by-wire aircraft and method of flying a fly-by-wire aircraft is disclosed. The aircraft includes a control system for flying the aircraft in one of a proportional ground control mode and a model following controls mode. A control device at a control interface of the aircraft selectively activates a trim follow up function in the control system. When flying the aircraft in a proportional ground control mode, trim follow up function can be activated. The control system can then transition into the model following controls mode with the trim follow up function activated to reduce transient behavior.

Pilot activated trim for fly-by-wire aircraft

A method for directing formation flying of an aircraft includes sensing a relative position of a leader to a follower aircraft by one or more sensors disposed at the follower aircraft. The relative position is compared to a selected relative position, and a follower velocity of the follower aircraft necessary to move the follower aircraft to the selective relative position is determined via a flight control computer of the follower aircraft. The follower velocity is transformed into flight control inputs and the follower aircraft is moved to the selected relative position via the flight control inputs.

Formation flying method and system

A system and method for counteracting a rotor moment of one or more rotors of a coaxial rotor helicopter includes receiving signals with a processor indicative of a displacement command from a controller during a flight maneuver; receiving one or more signals with the processor from a sensor indicative of an airspeed and air density for the helicopter; determining a commanded rate of acceleration for the helicopter during the flight maneuver; and adjusting with one or more control servos a cyclic pitch for the one or more rotors to counteract the rotor moment during the flight maneuver.

Feed-forward compensation for gyroscopic loads in a coaxial rotor

An aircraft is provided and includes an airframe defining a cockpit with first and second control stations configured for co-activation and complementary deactivation, flight control assemblies disposed at multiple locations of the airframe and a flight control computer (FCC). The FCC is configured to control operations of the flight control assemblies in accordance with current flight conditions and commands received at activated ones of the first and second control stations that are inputted by a flight crew. The FCC includes a secondary monitoring system to identify when commands are input at a deactivated one of the first and second control stations, to determine whether the commands are indicative of normal and intentional piloting inputs and to generate control station cues in an event the commands are indicative of normal and intentional piloting inputs to alert the flight crew of a hazardous condition or automatically turn the station back on.

Station deselect and cueing system

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

An aircraft is provided and includes one or more main rotors, one or more and propellers including blades that are rotatable about a rotational axis, a pitch of each of the blades being controllable, and a flight control computer disposed to control the pitch of each of the blades to reduce propeller blade pitch angles in an event of an engine failure.

Automatic propeller torque protection system

A system and method for estimating rotor mixing commands for an aircraft includes receiving signals indicative of reference commands from one or more controllers; receiving signals indicative of airspeed and sideslip angle for the aircraft, the sideslip angle being indicative of a direction of flight for the aircraft; calculating a sine and cosine of the sideslip angle; determining gains for roll and pitch as a function of the airspeed, the determining including referencing a look-up table that indexes the gain constants with the airspeed; and determining the one or more rotor mixing commands from the determined gains, the one or more rotor mixing commands being applied synchronously to the rotors in the aircraft.

Coaxial rotor low-speed mixing

Embodiments are directed to obtaining data from a plurality of sensors located on a rotorcraft, wherein a first plurality of the sensors is associated with a hub of the rotorcraft and a second plurality of the sensors is associated with blades of the rotorcraft, processing the data to isolate blade dynamics using the data from the sensors associated with the blade from rotorcraft maneuvering dynamics using the data from the sensors associated with the hub, obtaining at least one parameter associated with the blade dynamics based on the processing, and analyzing the at least one parameter to control at least one of the rotorcraft and the blades.

Relative acceleration blade position measurement

A rotor state sensor system is provided for use with a rotor including a hub, a hub arm and a blade coupled to the hub by the hub arm. The sensor system includes sensors disposed on the hub arm to define a first plane, which emit emissions and receive reflected emissions, and which generate a signal according to the received reflected emissions, reflector plates disposed on the blade which define a second plane at locations where the emissions from the sensors are incident on the reflector plates and from which the reflected emissions are reflected towards the sensors and a computing device which receives the signal from the sensors, determines relative orientations of the first and second planes according to the received signal and determines a condition of the rotor based on the determined relative orientations.

Rotor state sensor system

Embodiments are directed to generating, by a processing device, a feedback command for an aircraft based on a reference input and an output response of the aircraft, and analyzing, by the processing device, the feedback command to allocate control to a plurality of control surfaces over a plurality of separate frequency bands.

Pitch feedback control splitting for helicopters with redundant actuators

A control system for a rotor assembly includes a plurality of sensors configured to detect a lead-lag rate of each rotor blade of a plurality of rotor blades rotatable around a shaft and a flight control computer configured to generate lead-lag compensation signals based on the detected lead rate and lag rate of each rotor blade to control each rotor blade.

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Milford, CT, United States of America

Matthew A White