An aircraft includes a fuselage; a propulsion system including a power source and a vertical thrust electric fan oriented to generate thrust along a vertical direction and powered by the power source; and a wing extending from the fuselage and including the vertical thrust electric fan positioned at least partially therein. The wing includes a variable geometry assembly having partial wing assembly, the partial wing assembly including a frame and a first member, the partial wing assembly moveable generally along a longitudinal direction when the variable geometry assembly is moved between a forward thrust position and a vertical thrust position, the first member moveable relative to the frame to form an exhaust path for the vertical thrust electric fan.

An aircraft includes a fuselage; a propulsion system including a power source and a plurality of vertical thrust electric fans driven by the power source; and a wing extending from the fuselage. The plurality of vertical thrust electric fans are arranged along the wing, the wing including one or more components being moveable to selectively expose the plurality of vertical thrust electric fans, the wing further including a diffusion assembly positioned downstream of at least one vertical thrust electric fan of the plurality of vertical thrust electric fans, the diffusion assembly defining a diffusion area ratio greater than 1:1 and less than about 2:1.

An aircraft includes a fuselage; a propulsion system including a power source and a vertical thrust propulsor driven by the power source; and a wing extending from the fuselage, the vertical thrust propulsor positioned on or at least partially within the wing, the wing including a diffusion assembly, the diffusion assembly including at least one diffusion member fixed in position and located downstream of the vertical thrust propulsor for diffusing an airflow from the vertical thrust propulsor.

An aircraft includes a fuselage; a wing coupled to, and extending from, the fuselage; and a propulsion system. The propulsion system includes a plurality of electric fans integrated into the wing and oriented to generate thrust along a vertical direction, the plurality of electric fans arranged along a length of the wing and including an outer-most electric fan along a transverse direction relative to the fuselage. The outer-most electric fan is at least one of a variable pitch fan or a variable speed fan to provide increased stability to the aircraft.

A method for operating a vertical takeoff and landing aircraft includes modifying a first variable component of a wing associated with a first portion of the plurality of vertical thrust electric fans relative to a second variable component of the wing associated with a second portion of the plurality of vertical thrust electric fans to adjust an exposure ratio of the first portion of the plurality of vertical thrust electric fans relative to the second portion of the plurality of vertical thrust electric fans.

An aircraft defining a vertical direction and a transverse direction. The aircraft may include a fuselage, a wing extending from the fuselage, and a hybrid-electric propulsion system. The hybrid-electric propulsion system may include a power source, a plurality of vertical thrust electric fans arranged along the wing and driven by the power source, and a forward thrust propulsor. The power source may include a combustion engine and an electric generator. The combustion engine may also define a flowpath for exhausting combustion gases. The forward thrust propulsor may be selectively or permanently mechanically coupled to the combustion engine. The forward thrust propulsor may include a propulsor fan having a plurality of fan blades arranged outside of the flowpath of the combustion engine for exhausting combustion gases.

An aircraft includes a fuselage; a wing coupled to, and extending from, the fuselage; and a hybrid-electric propulsion system. The hybrid-electric propulsion system includes a power source including a combustion engine and an electric generator; a plurality of vertical thrust electric fans integrated into the wing and oriented to generate thrust along the vertical direction, the plurality of vertical thrust electric fans arranged along a length of the wing and driven by the power source; and a forward thrust propulsor. The forward thrust propulsor it is selectively or permanently mechanically coupled to the combustion engine.

A thermal management system for battery includes a plurality of cells, at least one inlet element having main inlet conduit and a plurality of inlet rail conduits, at least one outlet element having a main outlet conduit and a plurality of outlet rail conduits, and a plurality of battery holders. Each battery holder of the plurality of battery holders includes: a hollow wall structure surrounding a cavity in which a respective cell of the plurality of cells is to be accommodated; an inlet orifice; and an outlet orifice. The thermal management system may further include a coolant configured to be received via the main inlet conduit into a respective inlet rail conduit, wherein the coolant is configured to: circulate through the cavity of the hollow wall structure and exchange heat generated by the respective cell; and flow via a respective outlet rail conduit to the main outlet conduit.

A method of operating a hybrid engine for an aircraft, the hybrid engine having a thermal engine and an electric motor. The method includes verifying, using an engine control unit of the hybrid engine, that a selected power level is under a predetermined threshold for operation of the hybrid engine in a sub-idle hybrid mode. The method further includes operating the hybrid engine in the sub-idle hybrid mode, using the engine control unit, by controlling the thermal engine to operate in a standby mode, and by controlling the electric motor to operate in an active mode wherein the electric motor provides a majority of a propulsive power to the aircraft, wherein in the standby mode the thermal engine operates in a sub-idle condition to provide at most minimal propulsive power to the aircraft.

A secondary battery includes an electrode wound body including a positive electrode and a negative electrode, and includes an electrolytic solution. The positive electrode includes a positive electrode covered part and a positive electrode exposed part. The negative electrode includes a negative electrode covered part and a negative electrode exposed part. First edge parts of the positive electrode exposed part that is wound, second edge parts of the negative electrode exposed part that is wound, or both are bent toward a central axis to overlap each other, the first edge parts being adjacent to each other in a radial direction of the electrode wound body, the second edge parts being adjacent to each other in the radial direction. The electrolytic solution includes LiPF.sub.6 as an electrolyte salt. A concentration of the electrolyte salt in the electrolytic solution is within a range from 1.25 mol/kg to 1.45 mol/kg both inclusive.