Abstract: An exemplary gas turbine engine assembly includes a fan section including a fan, a first spool having a first turbine operatively mounted to a first turbine shaft, and a second spool having a second turbine operatively mounted to a second turbine shaft. The first and second towershafts are respectively coupled to the first and second turbine shafts. An accessory drive gearbox includes a set of gears. A compressor is driven by the first towershaft. A transmission couples a starter generator assembly to the set of gears. The transmission is transitionable between a first mode where the starter generator assembly is driven at a first speed relative to the second towershaft in response to rotation of the second towershaft, and a second mode where the starter generator assembly is driven at a different, second speed relative to the second towershaft in response to rotation of the second towershaft.

Abstract: An engine driven environmental control system (ECS) air circuit includes a gas turbine engine having a compressor section. The compressor section includes a plurality of compressor bleeds. A selection valve selectively connects each of said bleeds to an input of an intercooler. A second valve is configured to selectively connect an output of said intercooler to at least one auxiliary compressor. The output of each of the at least one auxiliary compressors is connected to an ECS air input.

Abstract: A turbine engine is disclosed that includes a fan case surrounding a fan rotatable about an axis. A core is supported relative to the fan case by support structure arranged downstream from the fan. The core includes a core housing having an inlet case arranged to receive airflow from the fan. A compressor case is arranged axially adjacent to the inlet case and surrounds a compressor stage having a rotor blade with a blade trailing edge. The support structure includes a support structure leading edge facing the fan and a support structure trailing edge on a side opposite the support structure leading edge. The support structure trailing edge is arranged axially forward of the blade trailing edge. In one example, a forward attachment extends from the support structure to the inlet case.

Abstract: A gas turbine engine may include a rotor overspeed protection (ROP) assembly. The ROP assembly may include an annular blade outer air seal (BOAS) assembly including a ROP segment. The ROP assembly may include a stator vane coupled with the BOAS assembly/. The stator vane may include a stator flange disposed about a forward edge portion of the stator vane. The ROP segment may include a ROP flange extending in an axially aft direction from a main body of the ROP segment toward the stator vane, wherein the ROP flange is disposed radially inward of the stator flange.

Abstract: A turbine engine is disclosed that includes a fan case surrounding a fan rotatable about an axis. A core is supported relative to the fan case by support structure arranged downstream from the fan. The core includes a core housing having an inlet case arranged to receive airflow from the fan. A compressor case is arranged axially adjacent to the inlet case and surrounds a compressor stage having a rotor blade with a blade trailing edge. The support structure includes a support structure leading edge facing the fan and a support structure trailing edge on a side opposite the support structure leading edge. The support structure trailing edge is arranged axially forward of the blade trailing edge. In one example, a forward attachment extends from the support structure to the inlet case.

Abstract: An engine driven environmental control system (ECS) air circuit includes a gas turbine engine having a compressor section. The compressor section includes a plurality of compressor bleeds. A selection valve selectively connects each of said bleeds to an input of an intercooler. A second valve is configured to selectively connect an output of said intercooler to at least one auxiliary compressor. The output of each of the at least one auxiliary compressors is connected to an ECS air input.

Abstract: An aircraft thermal management system includes a first fluid system containing a first fluid, a fluid loop containing a thermally neutral heat transfer fluid, a second fluid system containing a second fluid, a first heat exchanger configured to transfer heat from the first fluid to the thermally neutral heat transfer fluid, and a second heat exchanger configured to transfer heat from the thermally neutral heat transfer fluid to the second fluid. The fluid loop is configured to provide the thermally neutral heat transfer fluid to the first heat exchanger at a pressure that matches the pressure of the first fluid.

Abstract: An engine driven environmental control system (ECS) air circuit includes a gas turbine engine having a compressor section. The compressor section includes a plurality of compressor bleeds. A selection valve selectively connects each of said bleeds to an input of an intercooler. A second valve is configured to selectively connect an output of said intercooler to at least one auxiliary compressor. The output of each of the at least one auxiliary compressors is connected to an ECS air input.

Abstract: An exemplary gas turbine engine assembly includes a fan section including a fan, a first spool having a first turbine operatively mounted to a first turbine shaft, and a second spool having a second turbine operatively mounted to a second turbine shaft. The first and second towershafts are respectively coupled to the first and second turbine shafts. An accessory drive gearbox includes a set of gears. A compressor is driven by the first towershaft. A transmission couples a starter generator assembly to the set of gears. The transmission is transitionable between a first mode where the starter generator assembly is driven at a first speed relative to the second towershaft in response to rotation of the second towershaft, and a second mode where the starter generator assembly is driven at a different, second speed relative to the second towershaft in response to rotation of the second towershaft.

Abstract: A turbine exhaust assembly for a gas turbine engine according to an example of the present disclosure includes, among other things, a turbine exhaust case comprised of CMC material and attachable to a turbine case, a tail cone comprised of CMC material that has a leading edge and a trailing edge, and an exhaust mixer comprised of CMC material and coupled to the turbine exhaust case. The exhaust mixer has a plurality of lobes arranged about the tail cone to define an exhaust flow path. A plurality of struts extend from the tail cone to support the exhaust mixer at a location aft of the leading edge of the tail cone. A method of assembling a propulsion system is also disclosed.

Abstract: An exemplary gas turbine engine assembly includes a first spool having a first turbine operatively mounted to a first turbine shaft, and a second spool having a second turbine operatively mounted to a second turbine shaft. The first and second turbines are mounted for rotation about a common rotational axis within an engine static structure. The first and second turbine shafts are coaxial with one another. First and second towershafts are respectively coupled to the first and second turbine shafts. An accessory drive gearbox has a set of gears. A compressor is driven by the first towershaft. The engine assembly further includes a starter generator assembly, and a transmission coupling the starter generator assembly to the first set of gears.

Abstract: A turbine engine is disclosed that includes a fan case surrounding a fan rotatable about an axis. A core is supported relative to the fan case by support structure arranged downstream from the fan. The core includes a core housing having an inlet case arranged to receive airflow from the fan. A compressor case is arranged axially adjacent to the inlet case and surrounds a compressor stage having a rotor blade with a blade trailing edge. The support structure includes a support structure leading edge facing the fan and a support structure trailing edge on a side opposite the support structure leading edge. The support structure trailing edge is arranged axially forward of the blade trailing edge. In one example, a forward attachment extends from the support structure to the inlet case.

Abstract: An intercooled cooling system for a gas turbine engine includes a heat exchanger in fluid communication with a cooling airflow source directed through the heat exchanger and an auxiliary compressor fluidly coupled to the heat exchanger via a discharge duct to compress the cooling airflow exiting the heat exchanger. A compressor discharge pathway directs a first portion of the cooling airflow from the auxiliary compressor to a first cooling location of the gas turbine engine, and a bypass pathway is fluidly coupled to the discharge duct between the heat exchanger and the auxiliary compressor to direct a second portion of the cooling airflow to a second cooling location of the gas turbine without passing through the auxiliary compressor.

Abstract: A control system for a gas turbine engine comprises a case structure, a clearance control ring mounted for movement relative to the case structure, an outer air seal mounted to the clearance control ring and facing a first engine component, and a control and valve assembly that receives flow from a flow input source. The control and valve assembly is configured to direct flow into a first cavity positioned radially between the case structure and the outer air seal, and wherein the control and valve assembly is configured to direct flow into a second cavity positioned downstream of the first cavity to interact with a second engine component. A method of controlling flow between a compressor section and turbine section is also disclosed.

Abstract: A method for mounting a gas turbine engine having a compressor section, a combustor section, a turbine section, a pylon and a rear mount bracket, includes positioning the mounting bracket between the gas turbine engine and the pylon. The mounting bracket is connected to the turbine case reacting a least a vertical load, a side load, a thrust load, and a torque load from the gas turbine engine through the mounting bracket. The mounting bracket is attached to the pylon reacting the same loads from the gas turbine engine.

Abstract: A clearance control system for a gas turbine engine comprises at least one case support associated with an engine case defining an engine center axis. A clearance control ring is positioned adjacent the at least one case support to form an internal cavity between the engine case and the clearance control ring. The clearance control ring includes a first mount feature. An outer air seal has a second mount feature cooperating with the first mount feature such that the clearance control ring can move independently of the engine case in response to changes in temperature. An injection source inject flow into the internal cavity to control a temperature of the clearance control ring to allow the outer air seal to move in a desired direction to maintain a desired clearance between the outer air seal and an engine component. A gas turbine engine and a method of controlling tip clearance in a gas turbine engine are also disclosed.

Abstract: A non-metallic tailcone in a tip turbine engine includes a tapered wall structure disposed about a central axis. The non-metallic tailcone is fastened to a structural frame in the aft portion of the tip turbine engine. The tip turbine engine produces a first temperature gas stream from a first output source and a second temperature gas stream from a second output source. The second temperature gas stream is a lower temperature than the first temperature gas stream. The second temperature gas stream is discharged at an inner diameter of the tip turbine engine over an outer surface of the tailcone. Discharging the cooler second temperature gas stream at the inner diameter allows a non-metallic to be used to form the tailcone.

Abstract: A gas turbine engine includes a plurality of rotating components housed within a compressor section and a turbine section. A first tap is connected to the compressor section and configured to deliver air at a first pressure. A heat exchanger is connected downstream of the first tap and configured to deliver air to an aircraft fuselage. A cooling compressor is connected downstream of the heat exchanger. A high pressure feed is configured to deliver air at a second pressure which is higher than the first pressure. The cooling compressor is configured to deliver air to at least one of the plurality of rotating components. A valve assembly that can select whether air from the first tap or air from the high pressure feed is delivered to the aircraft pneumatic system.

Abstract: A gas turbine engine may include a rotor overspeed protection (ROP) assembly. The ROP assembly may include an annular blade outer air seal (BOAS) assembly including a ROP segment. The ROP assembly may include a stator vane coupled with the BOAS assembly/. The stator vane may include a stator flange disposed about a forward edge portion of the stator vane. The ROP segment may include a ROP flange extending in an axially aft direction from a main body of the ROP segment toward the stator vane, wherein the ROP flange is disposed radially inward of the stator flange.

Abstract: An exemplary gas turbine engine includes a turbine section and a fan mechanically connected to the turbine section such that rotation of the turbine drives rotation of the fan. The fan includes a hub, a plurality of blade bodies extending radially outward from the hub to a first partial shroud, and a plurality of blade tips extending radially outward from the partial shroud.