A method for stabilizing a motion of a rotor blade of a rotor comprising the steps: read into a controller, a measurement from a sensor responsive to said rotor blade; determine an out-of-compliance motion of the rotor blade; and output a first control signal to an actuator affecting the rotor blade such that a vibration mode of said rotor blade is dampened. The damping may be achieved by changing the drag, lift or torsion of the rotor blade. The out-of-compliance motion may be a lead, lag, upward motion, downward motion or twist of the rotor blade away from a nominal value.

A method for stabilizing a motion of a rotor blade of a rotor comprising the steps: read into a controller, a measurement from a sensor responsive to said rotor blade; determine an out-of-compliance motion of the rotor blade; and output a first control signal to an actuator affecting the rotor blade such that a vibration mode of said rotor blade is dampened. The damping may be achieved by changing the drag, lift or torsion of the rotor blade. The out-of-compliance motion may be a lead, lag, upward motion, downward motion or twist of the rotor blade away from a nominal value.

A system to prevent or limit resonance in a rotocraft. The system comprises an airframe, a rotor system having a natural frequency and including a rotor and a mast attached to the airframe, and a non-linear spring positioned between the rotor system and the airframe. The rotor system and the airframe are operable to move relative to each other as the rotor system begins to oscillate. The non-linear spring is configured to be deformed when the rotor system and the airframe move relative to each other such that the deformation of the non-linear spring causes the natural frequency of the rotor system to change. Also disclosed is a related method for preventing or limiting resonance in a rotorcraft.

A system to prevent or limit resonance in a rotocraft. The system comprises an airframe, a rotor system having a natural frequency and including a rotor and a mast attached to the airframe, and a non-linear spring positioned between the rotor system and the airframe. The rotor system and the airframe are operable to move relative to each other as the rotor system begins to oscillate. The non-linear spring is configured to be deformed when the rotor system and the airframe move relative to each other such that the deformation of the non-linear spring causes the natural frequency of the rotor system to change. Also disclosed is a related method for preventing or limiting resonance in a rotorcraft.

A flight control system for an aircraft includes a flight control computer operatively interconnected with a main rotor system and a translational thrust system of the aircraft. A selectively enabled integrated target and flight control system arranged in communication with the flight control computer. The integrated target flight and control system is configured to control pitch attitude and heading of the aircraft. When the integrated target and flight control system is enabled, at least partial operation of the aircraft is controlled in response to a pilot input via the flight control computer.

A rotary wing aircraft includes an airframe including an extending tail. The airframe includes a longitudinal axis that extends through the extending tail. The rotary wing aircraft also includes a main rotor assembly including at least one rotor hub supporting a plurality of rotor blades configured and disposed to rotate about a main rotor axis, at least one elevator arranged at the extending tail, and a control system operably connected to the main rotor assembly and the at least one elevator. The control system is configured and disposed to adjust each of a pitch rate and an attitude of the airframe by selectively adjusting a position of the at least one elevator.

A rotary wing aircraft includes an airframe including an extending tail. The airframe includes a longitudinal axis that extends through the extending tail. The rotary wing aircraft also includes a main rotor assembly including at least one rotor hub supporting a plurality of rotor blades configured and disposed to rotate about a main rotor axis, at least one elevator arranged at the extending tail, and a control system operably connected to the main rotor assembly and the at least one elevator. The control system is configured and disposed to adjust each of a pitch rate and an attitude of the airframe by selectively adjusting a position of the at least one elevator.

A method of assisting a pilot in order to minimize the risks of an aircraft rolling over on the ground, the aircraft having a main rotor and a yaw movement control rotor (4), together with lateral cyclic pitch control means for the main rotor and yaw movement control means for the yaw movement control rotor. At least one measurement is taken relating to left forces exerted on a left side undercarriage and to right forces exerted on a right side undercarriage in order to evaluate asymmetry, if any, between the left and right forces, and then a recommended position (26) is determined for at least one of the yaw and lateral cyclic pitch control means in order to make the left and right forces more symmetrical. Each recommended position is displayed on a display unit.

A method of assisting a pilot in order to minimize the risks of an aircraft rolling over on the ground, the aircraft having a main rotor and a yaw movement control rotor (4), together with lateral cyclic pitch control means for the main rotor and yaw movement control means for the yaw movement control rotor. At least one measurement is taken relating to left forces exerted on a left side undercarriage and to right forces exerted on a right side undercarriage in order to evaluate asymmetry, if any, between the left and right forces, and then a recommended position (26) is determined for at least one of the yaw and lateral cyclic pitch control means in order to make the left and right forces more symmetrical. Each recommended position is displayed on a display unit.

A method of assisting in rotor speed control in a rotorcraft can include measuring a rotor speed with a sensor; detecting a droop in the rotor speed beyond a lower droop limit; and commanding a decrease in collective in response to the rotor speed drooping beyond the lower droop limit. A system of assisting in rotor speed control in a rotorcraft, the system can include: a computer having a control law, the control law operable to generate a decrease collective command to an actuator in response to a rotor speed decreasing below a lower droop limit; wherein the lower droop limit is below a normal lower rotor speed range.