A method of assisting the piloting of an aircraft. A collective pitch margin of a main rotor is determined by applying a recursive algorithm using a main relationship that supplies said collective pitch margin at each current calculation instant as a function of the quotient of a limiting power margin divided by a denominator, the denominator being equal to the product of a first term multiplied by a second term, the first term being a function of the current collective pitch at said current calculation instant and of the collective pitch limit at a previous calculation instant prior to said current calculation instant, said second term being a function at least of a predetermined coefficient for reducing said power margin of the power plant.

Multi-rotor rotorcraft comprise a fuselage, and at least four rotor assemblies operatively supported by and spaced-around the fuselage. Each of the at least four rotor assemblies defines a spin volume and a spin diameter. Some multi-rotor rotorcraft further comprise at least one rotor guard that is fixed relative to the fuselage, that borders the spin volume of at least one of the at least four rotor assemblies, and that is configured to provide a visual indication of the spin volume of the at least one of the at least four rotor assemblies. Various configurations of rotor guards are disclosed.

The present invention relates to a control method in case of engine failure of a hybrid helicopter having a power plant connected to at least one lift rotor and to at least one propeller, said lift rotor having a plurality of first blades and said at least one propeller having a plurality of second blades. The method comprises the following steps: (i) measuring a forward speed of the hybrid helicopter, (ii) on condition that said forward speed is greater than a first speed threshold and that each engine has failed, automatically implementing a first emergency piloting mode comprising a step for automatic reduction by an automatic piloting system of a pitch of said second blades toward an objective pitch making said at least one propeller produce a motive power which is transmitted to the lift rotor.

Systems, devices, and methods for stopping the rotation of propellers used in unmanned aerial vehicles (UAV) such as drones are disclosed. The propellers are stopped in response to detecting when beams of light adjacent the propellers are blocked.

An aerial vehicle, configured to transport cargo, and including a propulsion system and a foldable cage is described. The foldable cage is substantially linear while in a folded configuration, and substantially circular while in a deployed configuration. Moreover, the foldable cage includes a rods that form isosceles triangles. The rods are coupled together by flexible joints.

A helicopter rotor blade performance system (BPS) allows for accurate determination of blade track height and blade track phase while reducing size, weight, and complexity of the system. The BPS uses sensing technology that is scalable to adapt to a variety of helicopters and is readily and unobtrusively installed. The BPS includes a bused smart system methodology that can directly measure track height, while phase can be estimated using the time synchronous average of the magnitude or range of the return signal from a radar wave. The BPS includes a rotation monitor, radar tracker, and control unit, that allows for a determination of the track errors and consequentially whether a track rebalancing should occur.

An impact mitigation system for an aircraft and method of deploying the impact mitigation system is disclosed. A state parameter of the aircraft is obtained. The state parameter is used with an aircraft performance model to determine an acceleration capability of the aircraft. A trajectory of the aircraft is predicted using the state parameter of the aircraft and the acceleration capability of the aircraft. A location of an object with respect to the aircraft is determined and the impact mitigation system is deployed when the predicted trajectory indicates a contact with the object at a predicted contact velocity higher than a threshold velocity at a future time.

According to one embodiment, a rotorcraft includes a body, a rotor blade, a drive system that can be operated to rotate the rotor blade, and an emergency valve control unit. The drive system contains a first gearbox assembly, a second gearbox assembly, a first lubrication system that can deliver lubricant to the first gearbox assembly, and a second lubrication system that can deliver lubricant to the second gearbox assembly. The drive system also contains an emergency valve that can be opened to deliver lubricant from the first lubrication system to the second gearbox assembly. The emergency valve control unit can instruct the emergency valve to open.

A system for sensing data in an aircraft, includes a plurality of wireless sensors, a receiver to sample a random subset of the plurality of wireless sensors at each of a plurality of times to generate a data matrix with a plurality of sampled entries and a plurality of missing entries, and an analysis unit to analyze the data matrix to provide a plurality of solutions corresponding to the plurality of missing entries using numerical analysis.

Systems and methods of warning a pilot of a helicopter about a servo transparency condition include devices and steps for retrieving, from a design performance database, a plurality of design performance parameters of the helicopter, and receiving avionics data from an avionics data source, the avionics data representative of a plurality of actual performance parameters of the helicopter. The design performance parameters and the avionics data are processed to determine whether one or more of the actual performance parameters exceed the design performance parameters, thereby indicating a servo transparency condition exists. One or more alerts are generated when the servo transparency condition exists.