An aircraft engine includes a low pressure spool, a high pressure spool, and an alternative power source. The alternative power source is configured to add power to the high pressure spool. A controller is configured to determine a noise sensitive condition; and control, in response to determining the noise sensitive condition, the alternative power source to add power to the high pressure spool.

Systems and methods involving dynamic recharge features and functionality for electric vehicles and other applications are disclosed. In one example, an illustrative electro-mechanical power system may comprise an electric vehicle (EV) motor that drives a shaft, an EV battery module coupled to the EV motor, and a dynamic recharge system coupled to the EV battery module, wherein the DRS includes an ambient air intake, a turbo coupled to the air intake and configured to create power that is used to charge the EV battery module, and a generator assembly. Further, the generator assembly may include a generator and a generator control module, wherein the generator includes a rotor coupled to the turbo, and the generator control module includes control electronics that manage and provide the electrical energy as an output to the EV battery module and/or the EV motor. Other embodiments for differing applications are also disclosed.

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 voltage converter for an aircraft electrical system includes an input power line configured to receive input electrical power, an output power line configured to supply output electrical power to aircraft loads, conversion circuitry, and a controller. The conversion circuitry is configured to convert the input electrical power to supply the output electrical power based on one or more control parameters. The controller is configured to receive data relating to the aircraft loads and modify at least one control parameter based on the data.

A hybrid propulsion update system includes a controller in signal communication with a replaceable battery. The controller includes a tuning parameters storage unit configured to store at least one tuning parameter corresponding to the replaceable battery. The controller is configured to execute at least one optimization algorithm that utilizes the tuning parameters to control operation of the hybrid electric aircraft according to a first performance. The tuning parameters storage unit is configured to receive at least one updated tuning parameter from a controller updating device. The controller executes the at least one optimization algorithm that utilizes the at least one updated tuning parameter such that the hybrid electric aircraft operates according to a second performance that improves upon the first performance.

A hybrid propulsion system for an aircraft comprising: an engine disposed within a fuselage of the aircraft, two electrical generators disposed within the fuselage and connected to the engine, and two nacelles. Each nacelle comprises a proprotor, and two electric motors connected to the proprotor. Each electrical generator is connected to the two electric motors in each nacelle. The proprotors provide lift for vertical takeoff and landing in a helicopter mode. A fan is coupled to the fuselage and connected to two additional electric motors. Each additional electric motor is connected to one of the two electric generators.

Methods and systems for detecting a torque transmission failure in an aircraft power plant are provided. The system comprises a hydrostatic transmission for transmitting torque between a first shaft and a second shaft using hydraulic fluid, an a failure detector including a sensor configured to detect a pressure change in the hydraulic fluid. The failure detector is configured to generate an output indicative of the torque transmission failure in response to the pressure change having crossed a threshold.

The hybrid aircraft power plant can have an output shaft connectable to a load, the output shaft rotatable about an axis; a thermal engine having a thermal engine shaft coaxial with the output shaft; an electric motor having a rotor shaft coaxial with the output shaft; a first clutch operable to engage the thermal engine shaft with the output shaft; a second clutch operable to engage the rotor shaft with the output shaft; a third clutch operable to engage the thermal engine shaft with the rotor shaft; the first clutch, second clutch and third clutch disposed axially between the electric motor and the thermal engine, relative to the axis.

A hybrid propulsion system for an aircraft comprising: an engine disposed within a fuselage of the aircraft, two electrical generators disposed within the fuselage and connected to the engine, and two nacelles. Each nacelle comprises a proprotor, and two electric motors connected to the proprotor. Each electrical generator is connected to the two electric motors in each nacelle. The proprotors provide lift for vertical takeoff and landing in a helicopter mode. A fan is coupled to the fuselage and connected to two additional electric motors. Each additional electric motor is connected to one of the two electric generators.

A system for determining and/or controlling motor thrust and engine thrust in a parallel hybrid aircraft. One or more sensors may be configured to monitor one or more flight parameters to generate sensor information. User input including one or more pilot estimates may be received. The sensor information may be obtained. A performance thrust ratio may be calculated based on the user input, the sensor information, an aerodynamic model, a propeller model, and a battery model. The performance thrust ratio may be used to control the motor thrust and engine thrust to improve utilization of electric energy throughout a flight. A first thrust setting for the motor and/or a second thrust setting for the engine may be determined based on the performance thrust ratio.