Abstract: In an embodiment, a method of indicating flight modes of a rotorcraft includes: detecting a change in flight mode of the rotorcraft from a previous flight mode to an active flight mode, the active flight mode and the previous flight mode each being from one of a first subset or a second subset of a plurality of flight modes; determining whether the active flight mode and the previous flight mode are from different subsets of the plurality of flight modes; and updating one or more flight mode indicators on an instrument panel of the rotorcraft in response to the active flight mode and the previous flight mode being from different subsets of the plurality of flight modes.

Abstract: In an embodiment, a rotorcraft includes: a rotor system; a sensor; a flight control device; and a flight control computer (FCC) coupled to the rotor system, the sensor, and the flight control device, the FCC configured to: determine a rotation speed of the rotor system; select a first aeroservoelasticity filter configuration from a plurality of aeroservoelasticity filter configurations according to the rotation speed of the rotor system, the aeroservoelasticity filter configurations being predetermined configurations corresponding to different rotation speeds of the rotor system; receive a signal from the sensor; filter the signal according to the first aeroservoelasticity filter configuration; and adjust the flight control device according to the filtered signal.

Abstract: In an embodiment, a rotorcraft includes: tail rotor blades; a tail rotor actuator coupled to the tail rotor blades such that the pitch of the tail rotor blades varies according to a current extension of the tail rotor actuator; pilot flight controls electrically coupled to the tail rotor actuator; and a flight control computer electrically coupled to the tail rotor actuator and the pilot flight controls, the flight control computer configured to: determine the current extension of the tail rotor actuator; determine whether the current extension of the tail rotor actuator is within a margin of a maximum extension of the tail rotor actuator; and indicate a first warning to a pilot in response to the current extension of the tail rotor actuator being within the margin of the maximum extension of the tail rotor actuator.

Abstract: In an embodiment, a rotorcraft includes: tail rotor blades; a tail rotor actuator coupled to the tail rotor blades such that the pitch of the tail rotor blades varies according to a current extension of the tail rotor actuator; pilot flight controls electrically coupled to the tail rotor actuator; and a flight control computer electrically coupled to the tail rotor actuator and the pilot flight controls, the flight control computer configured to: determine the current extension of the tail rotor actuator; determine whether the current extension of the tail rotor actuator is within a margin of a maximum extension of the tail rotor actuator; and indicate a first warning to a pilot in response to the current extension of the tail rotor actuator being within the margin of the maximum extension of the tail rotor actuator.

Abstract: A rotorcraft including a fly-by-wire control system also includes a flight control computer (FCC) operable to control flight of the rotorcraft by sending control signals to flight control elements of the rotorcraft. The rotorcraft includes a flight director system coupled to the FCC and configured to send a target signal to the FCC. The target signal indicates a desired flight characteristic of the rotorcraft. The FCC is configured to receive the target signal from the flight director system, determine control signals based on the target signal, and send the control signals to the flight control elements of the rotorcraft to control the flight of the rotorcraft based on the target signal.

Abstract: In an embodiment, a rotorcraft includes: a rotor system; a sensor; a flight control device; and a flight control computer (FCC) coupled to the rotor system, the sensor, and the flight control device, the FCC configured to: determine a rotation speed of the rotor system; select a first aeroservoelasticity filter configuration from a plurality of aeroservoelasticity filter configurations according to the rotation speed of the rotor system, the aeroservoelasticity filter configurations being predetermined configurations corresponding to different rotation speeds of the rotor system; receive a signal from the sensor; filter the signal according to the first aeroservoelasticity filter configuration; and adjust the flight control device according to the filtered signal.

Abstract: A flight control system includes a pilot control module configured to receive commands from a pilot, a flight control module operable to transmit an instruction to change at least one operating condition of an aircraft, and a flight control computer in communication between the flight control module and the pilot control module. The flight control computer is configured to receive a pilot command to change a first flight characteristic, wherein changing the first flight characteristic would result in an expected change to a second flight characteristic. The flight control computer may instruct the flight control module to transmit an instruction to change a first operating condition of the aircraft and instruct the flight control module to transmit an instruction to change a second operating condition of the aircraft to at least partially offset the expected change to the second flight characteristic.

Abstract: In an embodiment, a rotorcraft includes: tail rotor blades; a tail rotor actuator coupled to the tail rotor blades such that the pitch of the tail rotor blades varies according to a current extension of the tail rotor actuator; pilot flight controls electrically coupled to the tail rotor actuator; and a flight control computer electrically coupled to the tail rotor actuator and the pilot flight controls, the flight control computer configured to: determine the current extension of the tail rotor actuator; determine whether the current extension of the tail rotor actuator is within a margin of a maximum extension of the tail rotor actuator; and indicate a first warning to a pilot in response to the current extension of the tail rotor actuator being within the margin of the maximum extension of the tail rotor actuator.

Abstract: In an embodiment, a method of indicating flight modes of a rotorcraft includes: detecting a change in flight mode of the rotorcraft from a previous flight mode to an active flight mode, the active flight mode and the previous flight mode each being from one of a first subset or a second subset of a plurality of flight modes; determining whether the active flight mode and the previous flight mode are from different subsets of the plurality of flight modes; and updating one or more flight mode indicators on an instrument panel of the rotorcraft in response to the active flight mode and the previous flight mode being from different subsets of the plurality of flight modes.

Abstract: In an embodiment, a rotorcraft includes: tail rotor blades; a tail rotor actuator coupled to the tail rotor blades such that the pitch of the tail rotor blades varies according to a current extension of the tail rotor actuator; pilot flight controls electrically coupled to the tail rotor actuator; and a flight control computer electrically coupled to the tail rotor actuator and the pilot flight controls, the flight control computer configured to: determine the current extension of the tail rotor actuator; determine whether the current extension of the tail rotor actuator is within a margin of a maximum extension of the tail rotor actuator; and indicate a first warning to a pilot in response to the current extension of the tail rotor actuator being within the margin of the maximum extension of the tail rotor actuator.

Abstract: A flight control system having a control law, the control law operable to generate a modified pitch command, the modified pitch command representing a greater amount of collective pitch compared to an amount of collective pitch generated by a first pitch command, the modified pitch command being generated because a vertical descent speed of the rotorcraft at a given forward airspeed is greater than a threshold. A method of avoiding entry into an undesired vertical descent speed region during operation of a rotorcraft, including measuring a forward airspeed; evaluating a vertical descent of the rotorcraft; and generating a modified collective pitch command in respond to a first collective pitch command having a collective pitch value that would cause the rotorcraft to experience a vertical descent rate greater than a threshold value at the forward airspeed of the rotorcraft.

Abstract: A flight control system includes a pilot control module configured to receive commands from a pilot, a flight control module operable to transmit an instruction to change at least one operating condition of an aircraft, and a flight control computer in communication between the flight control module and the pilot control module. The flight control computer is configured to receive a pilot command to change a first flight characteristic, wherein changing the first flight characteristic would result in an expected change to a second flight characteristic. The flight control computer may instruct the flight control module to transmit an instruction to change a first operating condition of the aircraft and instruct the flight control module to transmit an instruction to change a second operating condition of the aircraft to at least partially offset the expected change to the second flight characteristic.

Abstract: According to one embodiment, a flight control system includes a pilot control assembly and a flight control computer. The pilot control assembly can receive commands from a pilot. The flight control computer can receive, from the pilot control assembly, a pilot command to change a first flight characteristic, wherein changing the first flight characteristic would result in an expected change to a second flight characteristic. The flight control computer can instruct, in response to the received pilot command, the flight control system to change a first operating condition of the flight control system based on an inherently-coupled relationship between the first flight characteristic and the second flight characteristic. The flight control computer can instruct, in response to the expected change to the second flight characteristic, the flight control system to change a second operating condition of the flight control system.

Abstract: According to one embodiment, a flight control system includes a pilot control assembly and a flight control computer. The pilot control assembly can receive commands from a pilot. The flight control computer can receive, from the pilot control assembly, a pilot command to change a first flight characteristic, wherein changing the first flight characteristic would result in an expected change to a second flight characteristic. The flight control computer can instruct, in response to the received pilot command, the flight control system to change a first operating condition of the flight control system based on an inherently-coupled relationship between the first flight characteristic and the second flight characteristic. The flight control computer can instruct, in response to the expected change to the second flight characteristic, the flight control system to change a second operating condition of the flight control system.

Abstract: According to one embodiment, a flight control system includes a pilot control module configured to receive commands from a pilot, a flight control module operable to transmit an instruction to change at least one operating condition of an aircraft, and a flight control computer in communication between the flight control module and the pilot control module. The flight control computer is configured to receive a pilot command to change a first flight characteristic, wherein changing the first flight characteristic would result in an expected change to a second flight characteristic. The flight control computer may instruct the flight control module to transmit an instruction to change a first operating condition of the aircraft and instruct the flight control module to transmit an instruction to change a second operating condition of the aircraft to at least partially offset the expected change to the second flight characteristic.

Abstract: According to one embodiment, a flight control system includes a pilot control module configured to receive commands from a pilot, a flight control module operable to transmit an instruction to change at least one operating condition of an aircraft, and a flight control computer in communication between the flight control module and the pilot control module. The flight control computer is configured to receive a pilot command to change a first flight characteristic, wherein changing the first flight characteristic would result in an expected change to a second flight characteristic. The flight control computer may instruct the flight control module to transmit an instruction to change a first operating condition of the aircraft and instruct the flight control module to transmit an instruction to change a second operating condition of the aircraft to at least partially offset the expected change to the second flight characteristic.

Abstract: A flight control system having a control law, the control law operable to generate a modified pitch command, the modified pitch command representing a greater amount of collective pitch compared to an amount of collective pitch generated by a first pitch command, the modified pitch command being generated because a vertical descent speed of the rotorcraft at a given forward airspeed is greater than a threshold. A method of avoiding entry into an undesired vertical descent speed region during operation of a rotorcraft, including measuring a forward airspeed; evaluating a vertical descent of the rotorcraft; and generating a modified collective pitch command in respond to a first collective pitch command having a collective pitch value that would cause the rotorcraft to experience a vertical descent rate greater than a threshold value at the forward airspeed of the rotorcraft.

Abstract: A rotor hub and method to dampen a force exerted on a rotor hub by a rotor blade during flight. The rotor hub including a central member rotatably coupled to a rotor mast, a blade grip rigidly attached to a blade and movably coupled to the central member, and an adjustable damper operably associated with the blade grip. The method includes damping the force exerted on the rotor hub with the adjustable damper and selectively adjusting the adjustable damper between a first spring rate and a second spring rate.

Abstract: A rotor hub and method to dampen a force exerted on a rotor hub by a rotor blade during flight. The rotor hub including a central member rotatably coupled to a rotor mast, a blade grip rigidly attached to a blade and movably coupled to the central member, and an adjustable damper operably associated with the blade grip. The method includes damping the force exerted on the rotor hub with the adjustable damper and selectively adjusting the adjustable damper between a first spring rate and a second spring rate.

Abstract: A damper has a piston having an axis, an outer surface, and opposing ends. Elastomeric seals are in sealing contact with the outer surface of the piston, the seals being coaxial with the piston and limiting movement of the piston to a path along the axis of the piston. The seals also define fluid chambers adjacent the ends of the piston. A primary passage communicates the fluid chambers, and a selectively switchable valve for controls a flow of fluid from one of the chambers to another of the chambers through the primary passage. When the flow of fluid through the primary passage is permitted, movement of the piston is resisted by a first spring rate due to a shear force required to cause shear deflection of the seals. When the flow of fluid through the primary passage is restricted, movement of the piston is resisted by a second spring rate due to a fluid force required to cause bulging deflection of the seals.