A method and system for operating a hybrid propulsion system, includes controllably providing a first power to a first bus and a first inverter, electrically coupling a first motor with a second inverter by way of a second bus, operably converting, by the second inverter, the first power received by the first inverter to a starting power adapted for starting the first motor, and increasing, by the second inverter, the starting power to match the first power received.

A method for operating a propulsion system for an aircraft, the propulsion system including a gas turbine engine and a fuel cell assembly, the fuel cell assembly including a fuel cell stack having a fuel cell defining an outlet positioned to remove output products from the fuel cell during operation, the method including: executing a startup sequence for the fuel cell assembly, wherein executing the startup sequence for the fuel cell assembly includes initiating the startup sequence for the fuel cell assembly; executing a startup sequence for the gas turbine engine, wherein executing the startup sequence for the gas turbine engine comprises initiating the startup sequence for the gas turbine engine subsequent to initiating the startup sequence for the fuel cell assembly; and operating the fuel cell assembly to provide output products to a combustion section of the gas turbine engine.

A method for operating a propulsion system for an aircraft, the propulsion system including a gas turbine engine and a fuel cell assembly, the fuel cell assembly including a fuel cell stack having a fuel cell defining an outlet positioned to remove output products from the fuel cell during operation, the method including: executing a startup sequence for the fuel cell assembly, wherein executing the startup sequence for the fuel cell assembly includes initiating the startup sequence for the fuel cell assembly; executing a startup sequence for the gas turbine engine, wherein executing the startup sequence for the gas turbine engine comprises initiating the startup sequence for the gas turbine engine subsequent to initiating the startup sequence for the fuel cell assembly; and operating the fuel cell assembly to provide output products to a combustion section of the gas turbine engine.

A method for operating a propulsion system for an aircraft, the propulsion system including a gas turbine engine and a fuel cell assembly, the fuel cell assembly including a fuel cell stack having a solid oxide fuel cell defining an outlet positioned to remove output products from the solid oxide fuel cell during operation, the method including: operating the fuel cell assembly to provide output products to a combustor of a combustion section of the gas turbine engine; and operating the fuel cell assembly, the gas turbine engine, or both such that a pressure within an anode of the solid oxide fuel cell is less than a pressure within a cathode of the solid oxide fuel cell, is less than a pressure within a combustion chamber of the gas turbine engine, or both while operating the gas turbine engine.

A method for operating a propulsion system for an aircraft, the propulsion system including a gas turbine engine and a fuel cell assembly, the fuel cell assembly including a fuel cell stack having a solid oxide fuel cell defining an outlet positioned to remove output products from the solid oxide fuel cell during operation, the method including: operating the fuel cell assembly to provide output products to a combustor of a combustion section of the gas turbine engine; and operating the fuel cell assembly, the gas turbine engine, or both such that a pressure within an anode of the solid oxide fuel cell is less than a pressure within a cathode of the solid oxide fuel cell, is less than a pressure within a combustion chamber of the gas turbine engine, or both while operating the gas turbine engine.

An aircraft control system includes: a first engine attached to an airframe of an aircraft; a second engine attached to the airframe; a first power generator connected to an engine shaft of the first engine; a second power generator connected to an engine shaft of the second engine; an electric motor driven with electric power supplied from one or both of the first power generator and the second power generator; a rotor driven with a driving force output from the electric motor; and a controller configured to estimate whether noise excess conditions have been satisfied on the basis of information for estimating noise and to change one or both of a rotation speed and a magnitude of a torque such that noise is lower than that before the noise excess conditions have been satisfied when it is estimated that the noise excess conditions have been satisfied.

An aircraft control system includes: a first engine attached to an airframe of an aircraft; a second engine attached to the airframe; a first power generator connected to an engine shaft of the first engine; a second power generator connected to an engine shaft of the second engine; an electric motor driven with electric power supplied from one or both of the first power generator and the second power generator; a rotor driven with a driving force output from the electric motor; and a controller configured to estimate whether noise excess conditions have been satisfied on the basis of information for estimating noise and to change one or both of a rotation speed and a magnitude of a torque such that noise is lower than that before the noise excess conditions have been satisfied when it is estimated that the noise excess conditions have been satisfied.

In some embodiments, a lift augmentation system for a blown lift aircraft includes a blown lift tailplane operatively coupled to the blown lift aircraft. The blown lift tailplane may include a leading edge and a trailing edge, an upper surface and a lower surface, and a first side and a second side. The lift augmentation system may include one or more tailplane thrust-producing devices on the first side and the second side of the blown lift tailplane operatively coupled to the leading edge of the blown lift tailplane. The one or more tailplane thrust-producing devices on the first side and the second side of the blown lift tailplane may produce a plurality of slipstreams corresponding to each of the tailplane thrust-producing devices. The plurality of slipstreams corresponding to each of the tailplane thrust-producing devices may blow over the upper surface and the lower surface of the blown lift tailplane.

In some embodiments, a lift augmentation system for a blown lift aircraft includes a blown lift tailplane operatively coupled to the blown lift aircraft. The blown lift tailplane may include a leading edge and a trailing edge, an upper surface and a lower surface, and a first side and a second side. The lift augmentation system may include one or more tailplane thrust-producing devices on the first side and the second side of the blown lift tailplane operatively coupled to the leading edge of the blown lift tailplane. The one or more tailplane thrust-producing devices on the first side and the second side of the blown lift tailplane may produce a plurality of slipstreams corresponding to each of the tailplane thrust-producing devices. The plurality of slipstreams corresponding to each of the tailplane thrust-producing devices may blow over the upper surface and the lower surface of the blown lift tailplane.

A double-ring rotary wing spherical cabin aircraft includes a spherical cabin; an upper protective cover; a lower protective cover; a rotary wing fixing ring connected between inner circles of the upper and lower protective covers, and mounted with a gyroscope and a rotatable attitude-adjusting ring; an upper rotary wing rotor and a lower rotary wing rotor rotationally mounted on the rotary wing fixing ring; and a control system. The spherical cabin is rotationally mounted in the attitude-adjusting ring. Two attitude-adjusting articulated shafts opposite to each other are connected between the attitude-adjusting ring and the rotary wing fixing ring. Two cabin articulated shafts opposite to each other are connected between the spherical cabin and the attitude-adjusting ring. The attitude-adjusting articulated shaft and the cabin articulated shaft are in transmission connection with an attitude-adjusting motor. The attitude-adjusting motor and the gyroscope are electrically connected to the control system.