A hybrid airship (drone, UAV) capable of significantly extended flight times can use one of two technologies, or both together. The first technology uses a combination of a lifting gas (such as hydrogen or helium) in a central volume or balloon and multirotor technology for lift and maneuvering. The second technology equips the airship with an on board generator to charge the batteries during flight for extended flight operations, with an internal combustion engine (such as a high power to weight ratio gas turbine engine) driving the generator. A quadcopter or other multicopter configuration is desirable.

An electrical architecture for an aircraft having a main electrical machine connected to a fuel burning engine and a secondary electrical machine connected to a power transmission assembly. A high-voltage electrical master box is connected by a first line and by a second line to a multifunction converter, the high-voltage electrical master box connecting the first line to the secondary electrical machine, and the second line to at least the main electrical machine and the secondary electrical machine. The multifunction converter includes a supervisor connected to an avionics system and to a control system controlling the engine, and to a controller of the high-voltage electrical master box.

A gas turbine engine includes a core having a compressor section with a first compressor and a second compressor, and a turbine section with a first turbine and a second turbine. The first compressor is connected to the first turbine via a first shaft and the second compressor is connected to the second turbine via a second shaft. An electric motor is connected to the first shaft such that rotational energy generated by the electric motor is translated to the first shaft. An electric energy storage component is electrically connected to the electric motor, and electrically connected to at least one aircraft taxiing system. The gas turbine engine is configured such that the gas turbine engine requires supplemental power from the electric motor during at least one mode of operations.

A gas turbine engine includes a core having a compressor section with a first compressor and a second compressor, a turbine section with a first turbine and a second turbine, and a primary flowpath fluidly connecting the compressor section and the turbine section. The first compressor is connected to the first turbine via a first shaft, the second compressor is connected to the second turbine via a second shaft, and a motor is connected to the first shaft such that rotational energy generated by the motor is translated to the first shaft. The gas turbine engine includes a takeoff mode of operation, a top of climb mode of operation, and at least one additional mode of operation. The gas turbine engine is undersized relative to a thrust requirement in at least one of the takeoff mode of operation and the top of climb mode of operation, and a controller is configured to control the mode of operation of the gas turbine engine.

Methods and systems for operating an aircraft power plant including an electric motor configured to propel an aircraft are provided. The methods and systems are used to mitigate a fault associated with the electric motor. The method includes receiving a power request from a power lever of the aircraft and using a controller to control the electric motor according to the power request. After a fault associated with the electric motor has been detected, the method includes receiving a deactivation request from the power lever. After receiving the deactivation request, the electric motor is deactivated independently of the controller.

An aircraft hybrid electrical propulsion (HEP) propulsion and attitude control system includes a propulsion system, electrical system and HEP controller. The propulsion system includes at least one propulsor and at least one electric motor configured to drive the at least one propulsor to generate to generate one or both of thrust and lift. The electrical system delivers a first amount of power to the at least one electric motor and a second amount of power to a plurality of electrical loads. The HEP controller determines at least one attitude goal of the aircraft, and controls the electrical system to adjust at least one of the thrust or lift to achieve the at least one attitude goal.

A method of operation is provided. During this method, a first power system of an aircraft powerplant is operated to provide a first quantity of power and/or torque to drive rotation of a propulsor rotor. A second power system of the aircraft powerplant is tested during the operating of the first power system. The second power system is configured as or otherwise includes an electric machine. The testing of the second power system includes: signaling the second power system to use the electric machine to provide a second quantity of power and/or torque to further drive the rotation of the propulsor rotor; determining an operational parameter of the aircraft powerplant following the signaling; and evaluating operability of the second power system by comparing the operational parameter to a threshold.

A series hybrid propulsion system of an aircraft includes a gas turbine engine, an electrical generator operably connected to the gas turbine engine configured to generate electrical power from operation of the gas turbine engine, and one or more electrically-driven propulsors configured to provide propulsion for the aircraft, and an electrical power grid configured to distribute electrical power generated at least at the electrical generator to the one or more electrically-driven propulsors. A voltage regulator is positioned downstream of the electrical generator and is configured to take one or more actions to compensate for a loss of load on the generator.

A turbo-compounded engine includes a piston engine connected to drive a propulsor. An outlet of the piston engine is operable to connect products of combustion from the piston engine to pass over a turbine. The turbine is connected to drive a turbine shaft also connected to drive the propulsor. An outlet of the turbine is connected into an exhaust duct configured to exhaust the products of combustion. The exhaust duct is provided with an exhaust duct outer wall defining an exhaust chamber. A further cooling air outer wall is positioned outwardly of the exhaust duct. Flow dividers are received within an exhaust chamber inward of the exhaust duct outer wall. The exhaust duct outer wall has an inner surface and the flow dividers have an outer surface. Acoustic treatment is provided on both the inner surface of the exhaust duct outer wall and the outer surface of the flow dividers.

The disclosure relates to an electrical power system for connecting an electrical machine to first and second DC networks operating at different voltages. In an embodiment, an electrical power system comprises: an electrical machine having first, second, third and fourth windings; first, second, third and fourth AC:DC power electronics converters each connected to receive an input AC supply from the respective first, second, third and fourth windings, each AC:DC power electronics converter having first and second DC output terminals connecting the AC:DC power electronics converters to first, second and third DC supply output terminals, wherein the first and second windings are arranged to provide an AC supply to the respective first and second AC:DC power electronics converters in quadrature to each other and the third and fourth windings are arranged to provide an AC supply to the respective third and fourth AC:DC power electronics converters in quadrature to each other.