Embodiments are directed to a flight control system for a helicopter comprises a pilot interface configured to receive a control input, at least one electronically controlled actuator, and a computing device configured to translate the control input to an actuator command, wherein the computing device is further configured to apply yaw rate limits to the actuator command to avoid loss of tail rotor effectiveness. The yaw rate limits are associated with a vortex ring state (VRS) envelope for a tail rotor of the helicopter. The electronically controlled actuator comprises a tail rotor actuator. The control input is a pedal input.

A rotorcraft including a main rotor, flight controls connected to the main rotor the main rotor, a plurality of engines connected to the main rotor and operable to drive the main rotor, a main rotor revolutions per minute (RPM) sensor, and a monitoring system operable to determine an engine failure of the plurality of engines. The monitoring system is further operable to engage an automated autorotation entry assist process in response to at least determining the engine failure and according to the measured main rotor RPM, where the automated autorotation entry assist process comprises the monitoring system generating one or more rotor RPM related commands according to at least a target main rotor RPM and the measured main rotor RPM, where the automated autorotation entry assist process further comprises controlling the one or more flight controls according to the one or more rotor RPM related commands.

The present invention includes a safety apparatus and method for protecting users during maintenance operations for a rotorcraft comprising: at least one permanent, semi-permanent, or detachable safety bar, strap, fastener, hook, or loop that is attached or attachable to a rotorcraft, wherein the safety bar, strap, fastener, hook, or loop is positioned in an area or surface between a windshield of the rotorcraft and a tail boom of the rotorcraft and is connectable to a user safety device to provide fall protection from the area or surface.

A method for stopping an engine of a rotorcraft in overspeed, the rotorcraft comprising at least one engine, the engine comprising a gas generator and a power assembly, the power assembly comprising at least one power turbine rotated by gases originating from the gas generator, the power assembly comprising at least one power shaft rotationally secured to the power turbine, the power assembly rotating about a longitudinal axis at a speed referred to as the “speed of rotation”. The method comprises steps consisting in measuring a current value of the speed of rotation, determining a time derivative of the current value of the speed of rotation, referred to as the “current derivative

[00001]$\left(\frac{dN2i}{dt}\right)”,$

and automatically stopping the engine when the current derivative

[00002]$\left(\frac{dN2i}{dt}\right)$

changes sign.

The invention relates to a method for controlling an emergency device of a helicopter, said helicopter comprising a rotor suitable for being rotated, said emergency device being suitable for supplying additional emergency propulsion power to the helicopter, in said method comprising a step (10) of measuring the rotation speed of the helicopter rotor, a step (12) of calculating the drift of the measured rotation speed, a step (20) of continuously verifying conditions such that the speed of rotation of the rotor is higher than a predetermined value, referred to as arming speed, and the drift of the rotation speed is lower than a predetermined value, referred to as arming drift, and a step (22) of activating the emergency device if the verified conditions are validated.

An exemplary distributed propulsion system with thermal management includes two or more rotors individually controlled by associated motors and an input control connected to the associated motors to demand the associated motors produce a demanded thrust, wherein a motor power output of each motor of the associated motors is independently controlled to produce the demanded thrust and to control a motor temperature of one or more of the associated motors.

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.

A multi-rotor aircraft includes a fuselage, a propulsion engine coupled to the fuselage that generates thrust to propel the aircraft along a first vector during forward flight, and rotors coupled to the fuselage, each rotor comprising blades, each rotor coupled to a motor, and each motor configured to supply power to and draw power from the coupled rotor. The aircraft includes a flight control system configured to control the motors coupled to the rotors in a power managed regime in which a net electrical power, consisting of a sum of the power being supplied to or drawn from each rotor by its motor, is maintained within a range determined by a feedback control system of the flight control system. The flight control system can also be leveraged to adjust rotor control inputs to modify at least one of thrust, roll, pitch, or yaw of the multi-rotor aircraft.

A method of evaluating fatigue damage of a rotor mast. The method includes performing an x-ray diffraction (“XRD”) inspection of the rotor mast, assessing fatigue damage sustained by the rotor mast based on results of the XRD inspection, and determining whether the rotor mast is suitable for continued use based on the assessed fatigue damage.

An aircraft provided with a rotary wing driven by a mechanical kinematic linkage, the aircraft having a power plant provided with at least one engine, the mechanical kinematic linkage comprising a free-wheel associated with the engine, the free-wheel comprising a driving part and a driven part, the driving part being connected by a mechanical connection to a working shaft of the associated engine and the driven part being connected kinematically to the rotary wing. A disengageable connection is arranged in parallel with the free-wheel in order to transmit mechanical power between the rotary wing and the engine on request, the power plant having a braking system comprising an engine brake of the engine.