Abstract: An aircraft powerplant assembly includes a rotor, a shroud, a casing, a structure and an air system. The structure circumscribes the casing with a plurality of air plenums formed by and disposed radially between the structure and the casing. The air plenums are arranged circumferentially around the axis in an array. The air plenums include a first plenum and a second plenum. The air system is configured to control a clearance between the shroud and an array of rotor blades using air. The air system includes a first air circuit and a second air circuit. The first air circuit is configured to direct a first flow of the air into the first plenum to cool a first section of the casing. The second air circuit is configured to direct a second flow of the air into the second plenum to cool a second section of the casing.

Abstract: An aircraft powerplant assembly includes a gearbox and a power coupler. The gearbox includes a first power transfer apparatus and a second power transfer apparatus. The first power transfer apparatus is configured to couple and transfer first mechanical power through the gearbox between a first engine apparatus and a first engine accessory. The second power transfer apparatus is configured to couple and transfer second mechanical power through the gearbox between a second engine apparatus and a second engine accessory during a first mode. The power coupler includes a variable speed transmission and a clutch. The variable speed transmission is coupled between the clutch and the second power transfer apparatus. The clutch is configured to couple the variable speed transmission to the second engine apparatus during the first mode. The clutch is configured to decouple the variable speed transmission from the second engine apparatus during a second mode.

Abstract: A method is provided for operating a turbine engine. During this method, a bladed turbine rotor is rotated about an axis. A turbine shroud is next to and circumscribes the bladed turbine rotor. A clearance is controlled between the bladed turbine rotor and the turbine shroud using a clearance control system. Operation of the clearance control system is tuned during turbine engine operation based on a change in an engine operating parameter over a period of time.

Abstract: An aircraft powerplant assembly includes a first electric device and a cooling system. The first electric device includes a first device heat exchanger, a first device housing and first electrical circuitry. The cooling system includes a liquid circuit, an air circuit and a system heat exchanger. The cooling system is configured to cool the first electrical circuitry using a liquid flowing in the liquid circuit and air flowing in the air circuit. The liquid circuit extends through the system heat exchanger and the first electric device. The first device heat exchanger is configured to transfer heat energy from the first electrical circuitry into the liquid in the liquid circuit. The air circuit extends through the system heat exchanger. The system heat exchanger is configured to transfer at least some of the heat energy from the liquid in the liquid circuit into the air in the air circuit.

Abstract: A propulsion system includes a gas turbine engine, a nacelle, a bifurcation, an electrical assembly, and a thermal management assembly. The gas turbine engine includes a rotational assembly and an engine static structure. The engine static structure houses the rotational assembly. The nacelle forms an annular bypass duct radially between the engine static structure and the nacelle. The bifurcation extends between the engine static structure and the nacelle. The electrical assembly includes an electric machine and a control unit. The electric machine is coupled with the rotational assembly. The control unit is electrically connected to the electric machine. The control unit is disposed within the bifurcation. The thermal management assembly includes a control unit cooling circuit. The control unit cooling circuit is connected in fluid communication with and formed by the control unit. The control unit cooling circuit is disposed within the bifurcation.

Abstract: A propulsion system for an aircraft includes a propulsor rotor, a powerplant, a nacelle and a lockout system. The powerplant is coupled to and configured to drive rotation of the propulsor rotor. An electrical system for the powerplant is configured to receive electrical power from an electrical power source. The nacelle includes an access structure configured to move between a first position and a second position. The access structure at least partially covers the electrical system when in the first position. The access structure is arranged in the first position for propulsion system operation. The access structure is operable to be arranged in the second position for propulsion system maintenance and/or propulsion system inspection. The lockout system is configured to automatically trigger an operation to cut off the electrical power to the electrical system from the electrical power source when the access structure moves away from the first position.

Abstract: A system for and method of operating a propulsion system for an aircraft is provided. The propulsion system includes a gas turbine engine, an accessory gearbox, and an electric motor. The gas turbine engine includes a spool having a fan rotor with a plurality of fan blades, and a pitch control mechanism engaged with the fan blades. The method includes: providing rotational drive from the spool to the accessory gearbox; using the accessory gearbox to drive an electric motor to produce electrical energy, wherein the electric motor has a predetermined maximum rotational speed limit; and controlling the propulsion system to follow a predetermined descent portion of a flight profile for the aircraft, wherein controlling the propulsion system includes controlling the pitch control mechanism to alter an amount of thrust produced by the fan blades by altering a pitch of the fan blades.

Abstract: An assembly is provided for an aircraft powerplant. This assembly includes an aircraft engine, a control system and a conduit. The control system includes an electronic engine controller, a first electric device and a first electric cable electrically coupling the first electric device to the electronic engine controller. The electronic engine controller is configured to control operation of the aircraft engine using the first electric device. The conduit extends longitudinally from a first end of the conduit to a second end of the conduit. The first electric cable extends longitudinally in a bore of the conduit between the electronic engine controller and the first electric device. The conduit is configured to shield the first electric cable from electromagnetic interference generated outside of the conduit.

Abstract: A gas turbine engine is provided that includes first and second spools, an accessory gearbox, and a spool coupling device. The first spool includes a first compressor section and a first turbine section. The second spool includes a second compressor section and a second turbine section. The accessory gearbox (AG) is in drive communication with the second spool. The accessory gearbox includes an AG output shaft. The spool coupling device (SCD) is in drive communication with the first spool and the AG output shaft. The spool coupling device includes an SCD accessory dock and a transmission that is disposable in first or second spool engaged configurations. In the first spool engaged configuration, rotational drive from the first spool is provided to the SCD accessory dock, and in the second spool engaged configuration, rotational drive from the second spool is provided to the SCD accessory dock.

Abstract: An aircraft powerplant assembly includes a first electric device, a second electric device and a cooling system. The first electric device includes a first device housing and first electrical circuitry housed within an interior of the first device housing. The second electric device includes a second device housing and second electrical circuitry. The second electrical circuitry is housed within an interior of the second device housing. The cooling system is configured to cool the first electrical circuitry and the second electrical circuitry. The cooling system includes a first heat exchanger disposed laterally between and thermally coupled to the first electric device and the second electric device.

Abstract: An aircraft powerplant assembly includes a gearbox housing, a power transfer shaft, a first gear system, a second gear system and a power coupler. The second gear system is operationally independent of the first gear system. The power coupler is disposed within the interior of the gearbox housing. The power coupler is arranged with the power transfer shaft and is disposed between the first gear system and the second gear system. The power coupler is configurable in a first arrangement and a second arrangement. In the first arrangement, the power coupler operatively couples the first gear system to the power transfer shaft and operatively decouples the second gear system from the power transfer shaft. In the second arrangement, the power coupler operatively couples the second gear system to the power transfer shaft and operatively decouples the first gear system from the power transfer shaft.

Abstract: An aircraft propulsion system assembly includes a fan rotor, an inner flowpath, an outer flowpath and an inter-flowpath structure. The fan rotor includes a plurality of fan blades arranged circumferentially about an axis. The outer flowpath includes an outer flowpath inlet downstream of the fan rotor. The outer flowpath inlet is radially outboard of the inner flowpath inlet. The inter-flowpath structure is disposed radially between and partially forms the inner flowpath inlet and the outer flowpath inlet. The inter-flowpath structure includes a splitter and an actuator. The splitter forms a leading edge of the inter-flowpath structure. The actuator is configured to translate the splitter axially along the axis between a first position and a second position.

Abstract: An assembly is provided for an aircraft propulsion system. This assembly includes a compressor section, a combustor section, a turbine section, a flowpath, a tail cone structure, an electric machine and an electric fan. The flowpath includes a flowpath inlet and a flowpath exhaust. The flowpath extends through the compressor section, the combustor section and the turbine section from the flowpath inlet to the flowpath exhaust. The tail cone structure forms an inner peripheral boundary of the flowpath at the flowpath exhaust. The tail cone structure includes an internal volume and an outlet fluidly coupled with the internal volume. The electric machine is disposed within the internal volume. The electric fan is configured to flow air within the internal volume such that the air cools the electric machine and is exhausted from the tail cone structure through the outlet.

Abstract: A hybrid-electric aircraft propulsion system includes a gas turbine engine, an electrical assembly, and a gear train. The gas turbine engine includes a first rotational assembly rotatable about a rotational axis of the gas turbine engine. The electrical assembly includes a plurality of electric machines. The plurality of electric machines includes a first electric machine and a second electric machine. The gear train includes a first shaft, a second shaft, a third shaft, a first gear, a second gear, and a transmission assembly. The first shaft couples the first electric machine with the first rotational assembly. The second shaft is coupled with the second electric machine. The second shaft is selectively coupled with the third shaft by the transmission assembly. The first gear is mounted on the first shaft. The second gear is mounted on the third shaft and engaged with the first gear.

Abstract: A propulsion system includes an electrical assembly. The electrical assembly includes an electric machine, a control unit, and a thermal management assembly. The control unit is electrically connected to the electric machine. The thermal management assembly includes an electric machine cooling circuit, a control unit (CU) cooling circuit, and a pump assembly. The electric machine cooling circuit is connected in fluid communication with the electric machine. The CU cooling circuit is connected in fluid communication with the control unit. The pump assembly includes a pump shaft, a first pump rotor, and a second pump rotor. The first pump rotor and the second pump rotor are mounted on the pump shaft. The first pump rotor forms a coolant pump of the electric machine cooling circuit. The second pump rotor forms a coolant pump of the CU cooling circuit.

Abstract: An aircraft system includes a powerplant configured to drive rotation of a propulsor rotor during a first mode and a second mode. The powerplant includes a turbine engine, a first electric machine and a power coupler. A first rotating structure includes a first turbine rotor disposed along a core flowpath. The first electric machine is configured as an electric motor during the second mode. The first electric machine is disposed between the propulsor rotor and the turbine engine. The first electric machine includes a first electric machine rotor coupled to the propulsor rotor. The power coupler is disposed between the first electric machine and the turbine engine. The power coupler is configured to couple the first rotating structure to the first electric machine rotor during the first mode. The power coupler is configured to decouple the first rotating structure from the first electric machine rotor during the second mode.

Abstract: A system includes a nacelle, a gas turbine engine, and an electrical machine. The nacelle includes an upper bifurcation and an engine core compartment. The gas turbine engine includes a low pressure spool and is disposed within the nacelle. The electrical machine is disposed within the upper bifurcation and is configured to transfer mechanical power between the low pressure spool and the electrical machine.

Abstract: An assembly is provided for an aircraft powerplant. This assembly includes an electric device and a closed loop fluid circuit. The electric device includes a device housing and electrical circuitry housed within an interior of the device housing. The closed loop fluid circuit is configured to cool the electrical circuitry. The closed loop fluid circuit includes a circuit path and a plurality of circuit components. The circuit path extends through the circuit components. Each of the circuit components are at least partially housed within the interior of the device housing. The circuit components may include a heat exchanger.

Abstract: An assembly is provided for an aircraft powerplant. This assembly includes a first electric machine, a first controller and an air circuit. The first electric machine is configurable as a first electric motor and/or a first electric generator. The first controller is configured to control operation of the first electric machine. The first controller includes first electrical circuitry. The air circuit extends through the first controller. The air circuit is configured to cool the first electrical circuitry using pressurized air.

Abstract: An assembly is provided for an aircraft powerplant. This assembly includes a first powerplant component, a second powerplant component, a third powerplant component and a fluid system. The fluid system includes a first fluid circuit, a second fluid circuit, a third fluid circuit and a heat exchanger. The first fluid circuit extends through the heat exchanger and is configured to service the first powerplant component. The second fluid circuit extends through the heat exchanger and is configured to service the second powerplant component. The third fluid circuit extends through the heat exchanger and is configured to service the third powerplant component. The heat exchanger is configured as or otherwise includes a radiator.