An example system includes a turbine comprising an input port and mechanically coupled to a motor-generator and a compressor and control circuitry configured to determine whether a pressure of a fluid at the input port of the turbine is less than or equal to than a threshold pressure. In response to determining that the pressure of the fluid at the input port of the turbine is less than or equal to the threshold pressure, the control circuitry is configured to cause the motor-generator to operate in motor mode. The motor-generator is configured to be mechanically coupled to the compressor, and the motor-generator is configured to provide mechanical energy to drive the compressor when operating in motor mode.

A drive unit, particularly for the main rotor of a rotary wing aircraft, comprises: a planetary gear mechanism including a plurality of planetary gears. Each planetary gear has at least one planet wheel with toothing and the planetary gears are arranged concentrically to a central axis inside the planetary gear mechanism so that a rotatable shaft, in particular a rotor shaft of the rotary wing aircraft, can be driven by the planetary gears or the sun wheel. A compact and simplified drive unit can be provided in a very wide range of fields of use, particularly for driving a main rotor of a rotary wing aircraft. This can be achieved in that a first drive, particularly an electric drive, is integrated into at least one planetary gear, comprising a planet wheel and a planet wheel carrier, to form a first drive unit, so that the shaft can be set rotating by the first drive.

A battery heating system for a hybrid aircraft powertrain includes a combustion engine, a battery pack, a combustion engine coolant circuit, and a battery pack coolant circuit. The battery heating system further includes a heat exchanger configured to exchange heat between the combustion engine coolant circuit and the battery pack coolant circuit. The battery heating system further includes at least one throttling device operatively connected to one of the combustion engine coolant circuit or the battery pack coolant circuit. The battery heating system further includes a controller configured to transmit a signal to the at least one throttling device to adjust a flow of coolant through the heat exchanger of at least one of the combustion engine coolant circuit or the battery pack coolant circuit.

An electricity generation and propulsion system of an aircraft is provided. The electricity generation and propulsion system includes a fuselage, a hybrid-electric power generation system operably disposed in the fuselage and a ram air turbine (RAT) device. The RAT device is coupled with the hybrid-electric power generation system and is stowable in the fuselage and deployable to an exterior of the fuselage. The RAT device is operable as a RAT when deployed into an airstream that drives rotations of the RAT from which the hybrid-electric power generation system generates electricity, and the RAT device is operable as a propulsor when deployed and driven by the hybrid-electric power generation system.

An unmanned vehicle includes at least one navigation sensor configured to measure navigation data indicative of an environment, at least one status sensor configured to measure status data indicative of operating parameters of a hardware system and a computing system. The computing system includes a navigation engine configured to receive the navigation data and status data and plan a path through the environment and a security engine. The security engine is configured to detect that an unauthorized user is attempting to access the navigation data or the status data, send an alert to an authorized user indicating that the unauthorized user is attempting to access navigation data or status data, and send, to the unauthorized user, simulated data including one or both of simulated navigation data and simulated status data.

A hybrid electric propulsion system including: a gas turbine engine comprising a low speed spool, a high speed spool, and a combustor; a lubrication circuit comprising a bearing compartment, a supply pump, and a scavenger pump; an electric motor configured to augment rotational power of the low speed spool or the high speed spool; and a controller operable to: control the electric motor based upon a pressure differential between an interior of the bearing compartment and an exterior of the bearing compartment and to drive rotation of the low speed spool and/or the high speed spool via the electric motor responsive to a thrust command while fuel flow to the combustor is inhibited.

A propulsion system of an aircraft includes a hybrid electric gas turbine engine, and a nacelle at least partially enclosing the hybrid electric gas turbine engine. The nacelle includes a first nacelle half and a second nacelle half. Each of the first nacelle half and the second nacelle half include an outer nacelle sleeve, an inner nacelle sleeve radially offset from the outer nacelle sleeve such that a flowpath is defined between the outer nacelle sleeve and the inner nacelle sleeve, and an upper bifurcation connecting the outer nacelle sleeve to the inner nacelle sleeve at an upper end of the nacelle. The flowpath is circumferentially continuous between the upper bifurcation of the first nacelle half and the upper bifurcation of the second nacelle half.

An aircraft system is provided that includes a first gas turbine engine, a propulsor rotor, a second gas turbine engine, an electric generator and an electric component. The first gas turbine engine includes a first compressor section, a first combustor section, a first turbine section and a first flowpath. The propulsor rotor is rotatably driven by the first gas turbine engine. The second gas turbine engine includes a second compressor section, a second combustor section, a second turbine section and a second flowpath between a second inlet and a second exhaust. The second inlet and the second exhaust are each fluidly coupled with the first flowpath upstream of a combustor of the first combustor section. The electric generator is rotatably driven by the second gas turbine engine. The electric component receives electricity generated by the electric generator. The electric component is discrete from the first gas turbine engine.

Systems, apparatuses, and methods for overcoming the disadvantages of current air transportation systems that might be used for regional travel by providing a more cost effective and convenient regional air transport system. In some embodiments, the inventive air transport system, operational methods, and associated aircraft include a highly efficient plug-in series hybrid-electric powertrain (specifically optimized for aircraft operating in regional ranges), a forward compatible, range-optimized aircraft design, enabling an earlier impact of electric-based air travel services as the overall transportation system and associated technologies are developed, and platforms for the semi-automated optimization and control of the powertrain, and for the semi-automated optimization of determining the flight path for a regional distance hybrid-electric aircraft flight.

A turbomachine is provided. In one aspect, the turbomachine includes a rotating component and an electric machine that includes a stator assembly and a rotor assembly rotatable with the rotating component relative to the stator assembly. Further, the turbomachine includes an actuator coupled with the rotor assembly, the stator assembly, or both for moving the rotor assembly, the stator assembly, or both relative to one another. In addition, the turbomachine includes a controller configured to receive data indicating an operating state of the rotating component and cause the actuator to adjust a position of at least one of the stator assembly and the rotor assembly based at least in part on the operating state of the rotating component.