A method of operating an electrically powered rotorcraft of the type having a fuselage and a set of N rotors driven by a set of electric motors and coupled to the fuselage, N?4, under a failure condition preventing ordinary operation of the rotorcraft. The method includes entering a failsafe mode of operation wherein autorotation of at least four of the rotors is enabled. The method also includes using electrical braking associated with a selected group of the rotors to control pitch, roll and yaw of the rotorcraft.

[Object] To detect airspeed and an airflow direction with respect to an airframe of a motorized aircraft with high accuracy without increasing the cost and weight and rapidly control attitudes of an electric propulsion system and the airframe in accordance with fluctuations of the airspeed and airflow direction.

[Solving Means] An electric propulsion system control device includes: a first airspeed measurement unit that is mounted on an airframe of an aircraft and includes a first propulsion system parameter detector that detects a propulsion system parameter, the propulsion system parameter being a parameter of an electric propulsion system, the electric propulsion system being driven by an electric motor and rotating about a rotation axis as a center, and a first airspeed calculator that calculates first airspeed on a basis of the propulsion system parameter, the first airspeed being airspeed with respect to a first direction that is a direction of the rotation axis; a second airspeed measurement unit that is mounted on the airframe and measures second airspeed, the second airspeed being airspeed with respect to a second direction different from the first direction; and an airflow calculator that calculates airspeed and airflow direction with respect to the airframe on a basis of the first direction and the first airspeed and the second direction and the second airspeed.

[Object] To detect airspeed and an airflow direction with respect to an airframe of a motorized aircraft with high accuracy without increasing the cost and weight and rapidly control attitudes of an electric propulsion system and the airframe in accordance with fluctuations of the airspeed and airflow direction.

[Solving Means] An electric propulsion system control device includes: a first airspeed measurement unit that is mounted on an airframe of an aircraft and includes a first propulsion system parameter detector that detects a propulsion system parameter, the propulsion system parameter being a parameter of an electric propulsion system, the electric propulsion system being driven by an electric motor and rotating about a rotation axis as a center, and a first airspeed calculator that calculates first airspeed on a basis of the propulsion system parameter, the first airspeed being airspeed with respect to a first direction that is a direction of the rotation axis; a second airspeed measurement unit that is mounted on the airframe and measures second airspeed, the second airspeed being airspeed with respect to a second direction different from the first direction; and an airflow calculator that calculates airspeed and airflow direction with respect to the airframe on a basis of the first direction and the first airspeed and the second direction and the second airspeed.

An electrical module configured to be connected to a power shaft of a turbine engine of an aircraft. The electrical module being configured to draw off power from/inject power into the power shaft. The electrical module comprising an electric machine comprising a machine housing in which a stator and a rotor is mounted, configured to be mechanically connected to the power shaft, the machine housing having a cylindrical shape extending along a cylinder axis, a first electric converter mounted in a first housing, a second electric converter mounted in a second housing, the second converter being independent of the first converter, the first housing and the second housing each being in the shape of a half-cylinder extending along the cylinder axis so as to form a cylindrical assembly that is mounted as an extension of the machine housing of the electric machine to limit the size of the electrical module.

An electrical module configured to be connected to a power shaft of a turbine engine of an aircraft. The electrical module being configured to draw off power from/inject power into the power shaft. The electrical module comprising an electric machine comprising a machine housing in which a stator and a rotor is mounted, configured to be mechanically connected to the power shaft, the machine housing having a cylindrical shape extending along a cylinder axis, a first electric converter mounted in a first housing, a second electric converter mounted in a second housing, the second converter being independent of the first converter, the first housing and the second housing each being in the shape of a half-cylinder extending along the cylinder axis so as to form a cylindrical assembly that is mounted as an extension of the machine housing of the electric machine to limit the size of the electrical module.

An electrical machine for an aircraft electrical power system includes a stator having current-carrying coils and flux guiding stator iron defining one or more stator slots that house the current-carrying coils. The electrical machine further includes a rotor having a plurality of permanent magnets configured to interact with the stator to produce a torque. The electrical machine has an active parts mass, m.sub.act, which is a cumulated mass of components of the electrical machine that contribute to producing the torque. The electrical machine is configured to produce a peak rated torque, ?.sub.peak. The electrical machine has a slot current density, J.sub.slot,peak, when producing the peak rated torque, ?.sub.peak. A value of a machine parameter, ?, defined as: ?=?.sub.peak/(m.sub.act?J.sub.slot,peak) is greater than or equal to 5 ?Nm.sup.3 kg.sup.?1A.sup.?1.

An energy converter that utilizes compressed environmental air includes an air compressing unit, at least one first battery, at least one second battery, a plurality of direct current (DC) accessories. The air compressing unit includes a supply duct, a nozzle duct, a pressurized air tank, a compressor, a power-generating tube, and a plurality of air-flow generators. The compressor is in fluid communication with the supply duct. The pressurized air tank is in fluid communication with the compressor. The nozzle duct is in fluid communication with the pressurized air tank. The power-generating tube is in fluid communication with the pressurized air tank and nozzle duct. The plurality of air-flow generators is operatively coupled within the power-generating tube. The plurality of air-flow generators is electrically connected to the first battery that powers the plurality of DC accessories and is electrically connected to the second battery that powers the compressor via an inverter.

An electrical propulsion assembly that includes: a propeller that has a rotation axis, at least two electric motors offset relative to one another in a longitudinal direction parallel to the rotation axis of the propeller, a main drive shaft parallel to the rotation axis of the propeller to which the electric motor are coupled, a transmission system including an output shaft connected to the propeller and an input shaft connected to the main drive shaft. Also an aircraft including at least one such electrical propulsion assembly.

An electrical propulsion assembly that includes: a propeller that has a rotation axis, at least two electric motors offset relative to one another in a longitudinal direction parallel to the rotation axis of the propeller, a main drive shaft parallel to the rotation axis of the propeller to which the electric motor are coupled, a transmission system including an output shaft connected to the propeller and an input shaft connected to the main drive shaft. Also an aircraft including at least one such electrical propulsion assembly.

A power conversion system incorporated in a flight vehicle includes a power converter having a semiconductor element stored therein. An energy storage is disposed above the power converter in the vertical direction, the energy storage storing a solid or liquid energy source containing a neutron attenuating material. The power converter is provided with a movable mechanism that moves to shift in position according to a tilt of the flight vehicle. The movable mechanism includes slider rails and a slider movable unit.