A method can include perturbing an electric motor of a hybrid powerplant having the electric motor and a fuel powered engine. The method can include measuring a frequency response of the powerplant due to the perturbing of the electric motor to determine a health of the powerplant and/or one or more components thereof.

This disclosure describes at least embodiments of an aircraft monitoring system for an electric or hybrid airplane. The aircraft monitoring system can be constructed to enable the electric or hybrid aircraft to pass certification requirements relating to a safety risk analysis. The aircraft monitoring system can have different subsystems for monitoring and alerting of failures of a component, such as a battery pack, a motor controller, and/or a motors. The failures that pose a greater safety risk may be monitored and indicated by one or more subsystems without use of programmable components.

Nuclear Aircraft Transportation System “KARAVAN” with its components is represented by a group of inventions in the technical and organizational relations. The main and basic invention is Nuclear Aircraft Transportation System “KARAVAN” (NATS). This invention includes two other ones: Aircraft Thrust Nuclear Power Plant, (ATNPP), which in turn includes—Thermal Power Cycle of ATNPP, (TPC ATNPP). In addition, the represented group of inventions is made up of two more inventions: Maintenance System of ATNPP, (MS ATNPP) and Emergency Response System of NATSK, (ERS NATSK).

The concept of practical implementation of the presented group of inventions involves the fact that ATNPP, which is a large unmanned drone aircraft “Tiagach”, supplies the aero-train composed of a number of passenger liners and cargo transport planes using electric motors with traction electric energy in the air.

The power supply of such an aero-train is based on the onboard Nuclear Power Plant of the aircraft “Tiagach”. In this case, the transmission of electric power to the towed electric aircraft of the aero-train is carried out by means of electric split feeders and cables, connecting and disconnecting of which between airplanes of the aero-train is carried out in the air, by analogy with refueling of airplanes in the air with JP fuel.

During the flight of the aero-train on a logistically optimized route, electric airplanes can detach from and attach to the aero-train, taking off and landing along the flight route of the aero-train using their own electric accumulators. In addition, extra ATNPP may be included in the aero-train during its flight, if it is necessary to increase the thrust. At the same time, due to the use of nuclear power, such ATNPP can remain in the air for a conditionally indefinite period of time.

The invention is aimed at creating cost-effective air freight and passenger traffic.

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.

A system of a hybrid aircraft includes a first gas turbine engine including a fan, a high speed spool, and a low spool motor configured to drive rotation of the fan. The system also includes a second gas turbine engine and a controller. The controller is operable to determine an operating mode of the hybrid aircraft, control the low spool motor to drive rotation of the fan of the first gas turbine engine responsive to a thrust command while the second gas turbine engine is driven by commanding fuel combustion based on the operating mode, and accelerate the high speed spool of the first gas turbine engine and command fuel combustion at the first gas turbine engine based on a transition of the operating mode to perform a starting operation of the first gas turbine engine.

A system includes a gas turbine engine having a low speed spool, a high speed spool, and a combustor. The system also includes a low spool motor configured to augment rotational power of the low speed spool. The system further includes a controller configured to cause fuel flow. The controller is operable to control the low spool motor to drive rotation of the low speed spool responsive to a thrust command while the controller does not command fuel flow to the combustor.

A propulsion system including: a fuel cell assembly comprising a fuel cell, the fuel cell defining an outlet positioned to remove output products from the fuel cell and a fuel cell assembly operating condition; a combustion section that includes a combustor configured to receive a flow of aviation fuel from the aircraft fuel supply and further configured to receive the output products from the fuel cell; and a controller comprising memory and one or more processors, the memory storing instructions that when executed by the one or more processors cause the propulsion system to perform operations including: determining data indicative of at least one of an enthalpy or a composition of the output products from the fuel cell; and modifying the flow of aviation fuel from the aircraft fuel supply to the combustor based on the at least one of the enthalpy or the composition of the output products.

A gas turbine engine includes a fuel cell assembly including a fuel cell stack and defining a fuel cell assembly operating parameter, a fuel source, and a turbomachine. The turbomachine includes a compressor section, a combustor, and a turbine section arranged in serial flow order. The combustor is configured to receive a flow of fuel from the fuel source and further configured to receive output products from the fuel cell stack. A controller is configured to perform operations including receiving data indicative of system operation conditions, determining a set of fuel cell operating conditions to move the system emission output into or maintain the system emission output within an emissions range, and controlling the fuel cell assembly operating parameter according to the determined set of fuel cell operating conditions.

Systems and methods of aircraft thrust management are provided. For example, a propulsion system for an aircraft comprises a fuel cell assembly comprising a fuel cell, a turbomachine, and a controller comprising memory and one or more processors. The memory stores instructions that, when executed by the one or more processors, cause the propulsion system to perform operations including receiving data indicative of a propulsion system thrust discrepancy and modifying an output of the fuel cell in response to receiving data indicative of the propulsion system thrust discrepancy. Modifying the fuel cell output may include modifying output products, an electrical power output, or both of the fuel cell to balance the thrust provided by the propulsion system.

A safety management system for an aircraft, or a propulsion system thereof including a fuel cell assembly and a combustion engine, may include various sensors and controllers configured to execute a safety action. At least one sensor is configured to detect at least one operating parameter of the propulsion system, and a controller is configured to determine that the at least one operating parameter has achieved a safety threshold and to execute a safety action when the at least one operating parameter has achieved the safety threshold. The safety action is configured to control operation of the fuel cell assembly and to control operation of the combustion engine.