Abstract: An assembly for an aircraft propulsion system includes a case assembly, at least one seal, a first pressure sensor, and a computing system. The case assembly forms a cavity. The at least one seal is disposed on the case assembly. The at least one seal is configured to seal the cavity. The first pressure sensor is in fluid communication with the cavity. The first pressure sensor is configured to measure a first pressure within the cavity. The computing system is in signal communication with the first pressure sensor. The computing system includes a processor in communication with a non-transitory memory storing instructions, which instructions when executed by the processor, cause the processor to compare the first pressure to a pressure threshold value to identify a wear condition of the at least one seal.

Abstract: A secondary air system (SAS) of an aircraft engine that produces secondary airflow from a source of secondary air includes a hollow strut and one or more SAS feed pipes upstream thereof. The hollow strut extends radially through the main gas path of the engine and defines therein a strut conduit extending between a strut inlet and a strut outlet at opposite ends of the hollow strut. The strut outlet is in fluid flow communication with a buffer cavity for feeding the secondary airflow to the engine core. The SAS feed pipe includes an inlet receiving the secondary airflow from the source of secondary air, and an outlet in fluid flow communication with the strut inlet to feed the secondary airflow into the strut conduit. The SAS feed pipe has a sonic orifice therein, between the inlet and the outlet thereof.

Abstract: An aircraft engine has: a first component and a second component coaxially mounted about a central axis; a flow passage extending within an annular gap defined radially between the first component and the second component, the flow passage fluidly connecting a first zone to a second zone; a seal disposed in the flow passage between the first zone and the second zone, the seal extending from a seal base secured to the first component to a seal end radially spaced apart from the seal base; a deflector located downstream of the seal relative to a first flow flowing from the first zone to the second zone through the seal, the deflector extending from a deflector base secured to the second component to a deflector end radially spaced apart from the deflector base; and a radial gap defined radially between the seal end and the deflector end.

Abstract: A secondary air system (SAS) of an aircraft engine that produces secondary airflow from a source of secondary air includes a hollow strut and one or more SAS feed pipes upstream thereof. The hollow strut extends radially through the main gas path of the engine and defines therein a strut conduit extending between a strut inlet and a strut outlet at opposite ends of the hollow strut. The strut outlet is in fluid flow communication with a buffer cavity for feeding the secondary airflow to the engine core. The SAS feed pipe includes an inlet receiving the secondary airflow from the source of secondary air, and an outlet in fluid flow communication with the strut inlet to feed the secondary airflow into the strut conduit. The SAS feed pipe has a sonic orifice therein, between the inlet and the outlet thereof.

Abstract: A gas turbine engine has: a high-pressure turbine; a low-pressure turbine (LPT) having a LPT outer case and a LPT plenum extending around a central axis; a mid-turbine frame (MTF) assembly connecting the low-pressure turbine and the high-pressure turbine, the MTF assembly having: a MTF outer case defining an inlet for connection to a source of the cooling air, an intermediary plenum fluidly connected to the source of cooling air via the inlet, the intermediary plenum having a first air outlet and a second air outlet, and a MTF plenum disposed radially inwardly of the MTF outer case and fluidly connected to the source of the cooling air via the first air outlet of the intermediary plenum; and a cooling air conduit fluidly connecting the second air outlet of the intermediary plenum to the LPT plenum while bypassing the MTF plenum.