Abstract: A gas turbine engine includes a first spool associated with a primary combustor, a second spool associated with a secondary combustor, and a third spool, each spool including a compressor and a turbine mounted to a shaft. A transmission and accessory gearing are enclosed within an housing of an accessory gearbox. The transmission rotationally couples the third spool to the second spool and accessory gearing. A method of operating the gas turbine engine includes supplying a first fuel flow rate to the primary combustor and supplying a second fuel flow rate to the secondary combustor within an intermediate speed range of the gas turbine engine.

Abstract: An assembly is provided for an aircraft. This aircraft assembly includes a carrier, a first gear system, a second gear system and an idler. The first gear system includes a first sun gear, a first ring gear and a plurality of first intermediate gears. Each of the first intermediate gears is between and is meshed with the first sun gear and the first ring gear. Each of the first intermediate gears is rotatably mounted to the carrier. The second gear system includes a second sun gear, a second ring gear and a plurality of second intermediate gears. Each of the second intermediate gears is between and is meshed with the second sun gear and the second ring gear. Each of the second intermediate gears is rotatably mounted to the carrier. The idler gear couples the first ring gear to the second ring gear.

Abstract: An assembly is provided for an aircraft propulsion system. This assembly includes a carrier, a first gear system, a second gear system and a lock device. The first gear system includes a sun gear, a first ring gear and a plurality of first intermediate gears between and meshed with the sun gear and the first ring gear. Each of the first intermediate gears is rotatably mounted to the carrier. The second gear system includes a second ring gear and a plurality of second intermediate gears meshed with the second ring gear. Each of the second intermediate gears is rotatably mounted to the carrier. The lock device is configured to lock rotation of the carrier about an axis during a first mode. The lock device is configured to unlock rotation of the carrier about the axis during a second mode.

Abstract: An assembly is provided for an aircraft propulsion system. This assembly includes a compressor section, a combustor section, a turbine section and a flowpath extending sequentially through the compressor section, the combustor section and the turbine section. The assembly also includes a rotating structure, a geartrain, a propulsor rotor and a turbine. The rotating structure includes a turbine rotor within the turbine section. The geartrain is coupled to the rotating structure. The propulsor rotor is coupled to the geartrain. The rotating structure is configured to drive rotation of the propulsor rotor through the geartrain. The turbine is coupled to the geartrain. The turbine is configured to receive bleed gas from the flowpath.

Abstract: An assembly is provided for an aircraft propulsion system. This assembly includes a carrier, a first gear system, a second gear system and a lock device. The first gear system includes a sun gear, a first ring gear and a plurality of first intermediate gears between and meshed with the sun gear and the first ring gear. Each of the first intermediate gears is rotatably mounted to the carrier. The second gear system includes a second ring gear and a plurality of second intermediate gears meshed with the second ring gear. Each of the second intermediate gears is rotatably mounted to the carrier. The lock device is configured to lock rotation of the carrier about an axis during a first mode. The lock device is configured to unlock rotation of the carrier about the axis during a second mode.

Abstract: An assembly is provided for an aircraft propulsion system. This assembly includes a compressor section, a combustor section, a turbine section and a flowpath extending sequentially through the compressor section, the combustor section and the turbine section. The assembly also includes a turbine rotor, a propulsor rotor and an auxiliary turbine. The turbine rotor is within the turbine section. The turbine rotor is configured to rotatably drive the propulsor rotor. The auxiliary turbine includes an auxiliary turbine rotor. The auxiliary turbine rotor is configured to rotatably drive the propulsor rotor with the turbine rotor. The auxiliary turbine is configured to receive bleed gas from the flowpath.

Abstract: An assembly is provided for an aircraft propulsion system. This assembly includes a compressor section, a combustor section, a turbine section and a flowpath extending sequentially through the compressor section, the combustor section and the turbine section. The assembly also includes a rotating structure, a geartrain, a propulsor rotor and a turbine. The rotating structure includes a turbine rotor within the turbine section. The geartrain is coupled to the rotating structure. The propulsor rotor is coupled to the geartrain. The rotating structure is configured to drive rotation of the propulsor rotor through the geartrain. The turbine is coupled to the geartrain. The turbine is configured to receive bleed gas from the flowpath.

Abstract: An aircraft assembly includes a geartrain with a first gear system and a second gear system. The first gear system includes a first sun gear, a first ring gear, a plurality of first intermediate gears and a first carrier. The first sun gear and the first ring gear are each rotatable about an axis. The first intermediate gears are between and meshed with the first sun gear and the first ring gear. Each of the first intermediate gears is rotatably mounted to the first carrier. The second gear system is interconnected with the first gear system. The second gear system includes a second sun gear, a second ring gear, a plurality of second intermediate gears and a second carrier. The second intermediate gears are between and meshed with the second sun gear and the second ring gear. Each of the second intermediate gears is rotatably mounted to the second carrier.

Abstract: A first gear system includes a first sun gear, a first ring gear, first intermediate gears and a first carrier. The first intermediate gears are between and meshed with the first sun gear and the first ring gear. Each first intermediate gear is rotatably mounted to the first carrier. A second gear system includes a second sun gear, a second ring gear, second intermediate gears and a second carrier. The second ring gear is coupled to the first carrier. The second intermediate gears are between and meshed with the second sun gear and the second ring gear. Each second intermediate gear is rotatably mounted to the second carrier. A first propulsor rotor is coupled to the first carrier. A rotating structure is coupled to the first ring gear and includes a turbine rotor. The rotating structure is configured to drive rotation of the first propulsor rotor through the geartrain.

Abstract: An assembly is provided for an aircraft propulsion system. This assembly includes an engine core, a bypass duct and a bleed circuit. The engine core includes a compressor section, a combustor section, a turbine section and a core flowpath extending sequentially through the compressor section, the combustor section and the turbine section. The bypass duct includes a bypass flowpath outside of the engine core. The bleed circuit includes a bleed passage and a flow regulator. The bleed circuit is configured to direct bypass gas through the bleed passage from the bypass flowpath into the core flowpath when the flow regulator is in an open position. The bleed circuit is configured to cutoff gas flow through the bleed passage between the bypass flowpath and the core flowpath when the flow regulator is in a closed position.

Abstract: An assembly is provided for an aircraft. This assembly includes a first rotating structure, a second rotating structure and a seal assembly. The seal assembly is configured to seal an annular gap radially between the first rotating structure and the second rotating structure. The seal assembly includes an arm, a seal element and a seal land. The arm is cantilevered from and extends axially along the second rotating structure. The seal element is connected to the arm and forms a seal interface with the seal land. The seal land is connected to the first rotating structure.

Abstract: A gas turbine engine includes a first spool, a second spool, a third spool, and a epicyclic differential. The epicyclic differential includes a sun gear, planet gears supported from a planet carrier, a ring gear, and a locking member, each housed within an accessory gearbox. The planet carrier couples to the second spool. The sun gear couples to the third spool, and the ring gear couples to engine accessories. A method of operating the gas turbine engine includes supplying a first fuel flow rate to a primary combustor associated with the first and third spools and supplying a second fuel flow rate to a secondary combustor associated with the second spool based on a power lever angle within an intermediate power level range.

Abstract: An aircraft heat exchanger system according to an exemplary embodiment of this disclosure, among other possible things includes a first heat exchanger assembly that is disposed in an inlet duct assembly, and a skin heat exchanger assembly is in thermal communication with an outer surface of an aircraft structure. The skin heat exchanger is in fluid communication with the first heat exchanger such that a working fluid is communicated therebetween.

Abstract: A method of distributing power within a gas turbine engine is disclosed. In various embodiments, the method includes driving a high pressure turbine having a first stage and a second stage with an exhaust stream from a combustor, the first stage connected to a high pressure turbine first stage spool and the second stage connected to a high pressure turbine second stage spool; driving a high pressure compressor connected to a high pressure compressor spool via a differential system, the differential system having a first stage input gear connected to the high pressure turbine first stage spool, a second stage input gear connected to the high pressure turbine second stage spool and an output gear assembly connected to the high pressure compressor spool; and selectively applying an auxiliary input power into at least one of the high pressure compressor spool and the high pressure turbine.

Abstract: 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.

Abstract: A section for a gas turbine engine according to an example of the present disclosure includes, among other things, a rotor including a row of blades extending in a radial direction outwardly from a hub. The row of blades deliver flow to a bypass flow path, an intermediate flow path, and a core flow path. A first case surrounds the row of blades to establish the bypass flow path. A first flow splitter divides flow between the bypass flow path and a second duct. An aftmost row of guide vanes extends in the radial direction across the bypass flow path. A second flow splitter radially inboard of the first flow splitter divides flow from the second duct between the intermediate flow path and the core flow path. A bypass port interconnects the intermediate and bypass flow paths.

Abstract: A gas turbine engine includes a fan positioned at an engine central longitudinal axis, and a fan drive turbine located at the engine central longitudinal axis and configured to drive rotation of the fan. A gas generator is non-coaxial with the fan drive turbine and operably connected to the fan drive turbine such that exhaust from the gas generator drives rotation of the fan drive turbine. An auxiliary power core is located at the engine central longitudinal axis, and one or more bleed passages connect the gas generator and the auxiliary power core. The one or more bleed passages are configured to selectably combine a bleed airflow from the gas generator and an auxiliary core airflow at the auxiliary power core to direct the combined airflow to the fan drive turbine to increase output of the fan drive turbine.

Abstract: A propulsion system includes a first propulsor rotor, a second propulsor rotor and a gas turbine engine core. The first propulsor rotor is configured to generate propulsive thrust. The second propulsor rotor is configured to generate propulsive lift. The gas turbine engine core includes a compressor section, a combustor section, a turbine section and a rotating structure. The rotating structure includes a turbine rotor within the turbine section. The gas turbine engine core is configured to rotate the rotating structure at a first rotational speed during a first mode to drive the first propulsor rotor to generate the propulsive thrust. The gas turbine engine core is configured to rotate the rotating structure at a second rotational speed during a second mode to drive the second propulsor rotor to generate the propulsive lift. The second rotational speed may be less than eighty percent of the first rotational speed.

Abstract: An assembly is provided for an aircraft propulsion system. This assembly includes a sun gear, a ring gear, a plurality of intermediate gears, a carrier, a first brake and a second brake. The sun gear is rotatable about a centerline axis. The ring gear circumscribes the sun gear and is rotatable about the centerline axis. The intermediate gears are arranged circumferentially about the centerline axis. Each of the intermediate gears is meshed between the sun gear and the ring gear. The carrier is rotatable about the centerline axis. Each of the intermediate gears is rotatably mounted to the carrier. The first brake is configured to slow and/or stop rotation of the ring gear about the centerline axis. The second brake is configured to slow and/or stop rotation of the carrier about the centerline axis.

Abstract: A propulsion system is provided for an aircraft. This aircraft propulsion system includes a gas turbine engine core, a first propulsor rotor and a second propulsor rotor. The gas turbine engine core includes a compressor section, a combustor section, a turbine section and a rotating structure. The rotating structure includes a turbine rotor within the turbine section. The first propulsor rotor is rotatably driven by the rotating structure during a first mode and a second mode. The first propulsor rotor includes a plurality of variable pitch blades. The variable pitch blades include a first blade configured to pivot between a thrust position and an idle position. The first blade is in the thrust position during the first mode. The first blade is in the idle position during the second mode. The second propulsor rotor is rotatably driven by the rotating structure during the second mode.