A propeller-type propulsion system for aircraft, comprises a propeller, a plurality of electric motors comprising nested coaxial respective driveshafts, and a gearbox having an output shaft onto which the propeller is mechanically coupled, and an input shaft to which the coaxial driveshafts of the electric motors are mechanically coupled. As a result, the diameter of the propulsion system, in a plane perpendicular to the axis of rotation of the propeller, is reduced. This improves the aerodynamics and the fuel consumption of the aircraft.

A propeller-type propulsion system for aircraft, comprises a propeller, a plurality of electric motors comprising nested coaxial respective driveshafts, and a gearbox having an output shaft onto which the propeller is mechanically coupled, and an input shaft to which the coaxial driveshafts of the electric motors are mechanically coupled. As a result, the diameter of the propulsion system, in a plane perpendicular to the axis of rotation of the propeller, is reduced. This improves the aerodynamics and the fuel consumption of the aircraft.

A system of an electric aircraft with pitch control using an elevator is presented. In some embodiments, the electric aircraft may include an elevator configured to deflect. In some embodiments, the electric aircraft may further include a lift lever configured to generate a lift command upon activation by a pilot. In some embodiments, the electric aircraft may further include a flight controller communicatively connected with the lift lever and the elevator, wherein the flight controller is configured to receive the lift command from the lift lever and adjust the elevator as a function of the lift command.

In accordance with one embodiment of the present invention, an aircraft comprises a battery pack mounted external to the aircraft structure. The batteries are configured to vent directly to the environment during battery thermal runaway. In one embodiment, an aerodynamic fairing provides an aerodynamically efficient surface and weather protection during nominal flight conditions. During battery thermal runaway however, the aerodynamic fairing is configured to expose the battery to the environment.

In accordance with one embodiment of the present invention, an aircraft comprises a battery pack mounted external to the aircraft structure. The batteries are configured to vent directly to the environment during battery thermal runaway. In one embodiment, an aerodynamic fairing provides an aerodynamically efficient surface and weather protection during nominal flight conditions. During battery thermal runaway however, the aerodynamic fairing is configured to expose the battery to the environment.

In an embodiment, proprotor pitch ranges used during nominal cruise flight may be varied. By selecting ideal combinations of proprotor pitch angle and proprotor rpm, instead of the proprotor blade pitch bearing spending most of its time in a first range, multiple ranges may be alternated between. Additionally, in an aircraft with multiple proprotors, the portion of total thrust produced by each individual proprotor may be varied over time in order to allow for proprotor blade pitch angle to be varied without varying proprotor rpm. By properly cycling between different blade pitch ranges, bearing life can be significantly increased.

In an embodiment, proprotor pitch ranges used during nominal cruise flight may be varied. By selecting ideal combinations of proprotor pitch angle and proprotor rpm, instead of the proprotor blade pitch bearing spending most of its time in a first range, multiple ranges may be alternated between. Additionally, in an aircraft with multiple proprotors, the portion of total thrust produced by each individual proprotor may be varied over time in order to allow for proprotor blade pitch angle to be varied without varying proprotor rpm. By properly cycling between different blade pitch ranges, bearing life can be significantly increased.

A propulsor is provided including a gas turbine engine having a shaft and one or more bearings supporting the shaft, a rotor hub operatively coupled to the shaft and comprising a hub flange, an electric machine comprising a stator assembly and a rotor assembly, a rotor connection member operatively coupled to the rotor assembly of the electric machine and comprising a connection flange, and an insulated joint for operatively coupling the rotor assembly with the shaft. The insulated joint includes a plurality of insulative layers, at least one of the plurality of insulative layers extending between the hub flange and the connection flange to interrupt common mode electric current from flowing between the rotor assembly and the shaft.

A propulsor is provided including a gas turbine engine having a shaft and one or more bearings supporting the shaft, a rotor hub operatively coupled to the shaft and comprising a hub flange, an electric machine comprising a stator assembly and a rotor assembly, a rotor connection member operatively coupled to the rotor assembly of the electric machine and comprising a connection flange, and an insulated joint for operatively coupling the rotor assembly with the shaft. The insulated joint includes a plurality of insulative layers, at least one of the plurality of insulative layers extending between the hub flange and the connection flange to interrupt common mode electric current from flowing between the rotor assembly and the shaft.

An electric aircraft engine includes an electric motor driving a propulsor. A power source powers the electric motor. An electric compressor supplies compressed air. A nacelle surrounds the electric motor, the power source and the electric compressor. An aircraft and a method are also disclosed.