An aircraft emergency descent method includes setting a pre-set maximum collective blade pitch and a pre-set altitude as part of a failure procedure; monitoring rotor assemblies through an aircraft control system and a failure detection module; determining when a rotor assembly has failed; and activating the failure procedure. The failure procedure includes commanding a maximum torque to a motor of each rotor assembly such that the rotational velocity of functioning rotors increases; detecting the increase in rotational velocity; adjusting either motor torque or a collective blade pitch to regulate rotational velocity; monitoring altitude of the aircraft; and upon determining when the aircraft reaches the pre-set altitude, adjusting the collective blade pitch to the pre-set maximum collective blade pitch via the at least one governor such that momentum is conserved, causing a descent rate of the aircraft to decrease as the aircraft approaches a ground surface.

A hybrid electric propulsion system includes a turbomachine, an electric machine coupled to the turbomachine, and a propulsor coupled to the turbomachine. A method for operating the hybrid electric propulsion system includes operating the turbomachine to drive the propulsor; receiving data indicative of a failure condition of the hybrid electric propulsion system; reducing a fuel flow to a combustion section of the turbomachine in response to receiving the data indicative of the failure condition; and extracting power from the turbomachine using the electric machine to slow down one or more rotating components of the turbomachine in response to receiving the data indicative of the failure condition.

A set of commands for each of a plurality of actuators to alter an aircraft's state responsive to one or more inputs is produced. The set of commands is provided to fewer than all actuators comprising the plurality of actuators.

A method of operating a rotorcraft with at least one main rotor and at least two engines, comprising: determining whether the rotorcraft is operated in an AEO mode wherein the at least two engines are powering the at least one main rotor, or in a SEO mode wherein only a first engine of the at least two engines is powering the at least one main rotor while a second engine of the at least two engines is inactive; if the rotorcraft is operated in the SEO mode, monitoring the first engine to enable detection of engine failures; and if during monitoring of the first engine an engine failure of the first engine is detected, entering into autorotation of the at least one main rotor upon detection of the engine failure by adjusting main rotor actuators of the at least one main rotor.

A method of operating a rotorcraft with at least one main rotor and at least two engines, comprising: determining whether the rotorcraft is operated in an AEO mode wherein the at least two engines are powering the at least one main rotor, or in a SEO mode wherein only a first engine of the at least two engines is powering the at least one main rotor while a second engine of the at least two engines is inactive; if the rotorcraft is operated in the SEO mode, monitoring the first engine to enable detection of engine failures; and if during monitoring of the first engine an engine failure of the first engine is detected, entering into autorotation of the at least one main rotor upon detection of the engine failure by adjusting main rotor actuators of the at least one main rotor.

In one aspect, a method for dynamically controlling the operation of an aircraft having a first gas turbine engine and a second gas turbine engine may generally include receiving, by a first engine controller and a second engine controller, one or more operator commands deriving from an operator manipulated input device. The method may also include controlling the operation of the first gas turbine engine via the first engine controller, and the second gas turbine engine via the second engine controller. In addition, the method may include detecting a fault condition associated with the first engine controller, and subsequently switching control of the first gas turbine engine from the first engine controller to the second engine controller. The method may further include dynamically controlling the operation of the first gas turbine engine with the second engine controller.

An aircraft comprising at least two engines and an electronic management arrangement comprising a control computer for each engine, each computer being configured for monitoring the operation of its associated engine and for activating an engine protection mode when the engine operation exceeds predetermined operational limits. The electronic management arrangement furthermore comprises an engine interface device to which the control computers are connected, the device prohibiting the activation of a protection mode by a control computer when a protection mode is activated by another control computer. A monitoring device is connected to the control computers and receives an information signal from each control computer to indicate if a protection mode is activated and transmits, in the case where a protection mode is activated on at least two engines, a control signal to the control computer having last activated a protection mode to cancel the activation of the protection mode.

Improved aircraft, which may be configured as unmanned drones or piloted aircraft, having improved fail-operational performance. The aircraft includes a twin fan arrangement and innovative motor, propeller, driver and/or power source redundancies configured to provide fail-operational functioning in the event of failure of one or more of these aircraft components. In various optional features, the aircraft may be configured for vertical takeoff and landing. The disclosed embodiments provide an aircraft that is safer and more reliable than current multi-propeller drones, while operably more versatile in cargo delivery.

Improved aircraft, which may be configured as unmanned drones or piloted aircraft, having improved fail-operational performance. The aircraft includes a twin fan arrangement and innovative motor, propeller, driver and/or power source redundancies configured to provide fail-operational functioning in the event of failure of one or more of these aircraft components. In various optional features, the aircraft may be configured for vertical takeoff and landing. The disclosed embodiments provide an aircraft that is safer and more reliable than current multi-propeller drones, while operably more versatile in cargo delivery.

The invention relates to a device for the rapid reactivation of a helicopter turbine engine (6), characterised in that it comprises a pneumatic turbine (7) mechanically connected to said turbine engine (6) so as to be able to rotate it and ensure reactivation thereof; a pneumatic storage (9) connected to said pneumatic turbine (7) by means of a pneumatic circuit (10) for supplying pressurised gas to said pneumatic turbine (7); a controlled fast-opening pneumatic valve (11) arranged on the pneumatic circuit (10) between said storage (9) and said pneumatic turbine (7) and suitable for being on demand placed at least in an open position in which the gas can supply said pneumatic turbine (7), or in a closed position in which said pneumatic turbine (7) is no longer supplied with pressurised gas.