Abstract: The present disclosure relates to gas turbine engine and seal configurations, and components for a gas turbine engine. In one embodiment, a seal for a gas turbine engine includes a rotary seal element, the rotary seal element configured to rotate during operation of a gas turbine engine, and a stationary seal element having an annular seal surface. The stationary seal element includes a first area of the annular seal surface configured to engage with the rotary seal element, and the stationary seal element includes a second area of the annular seal surface configured to provide reduced resistance to the rotary seal element during a flight windmilling event.

Abstract: Aspects of the disclosure are directed to an active clearance control system for an engine of an aircraft, comprising: a collector that is configured to receive a cooling fluid, at least two manifolds coupled to the collector, where a first of the manifolds is configured to receive at least a first portion of the cooling fluid from the collector and a second of the manifolds is configured to receive at least a second portion of the cooling fluid from the collector, and an insert coupled to the collector and the manifolds, where the insert is configured to seal an interface between the collector and the at least two manifolds over an operating range of the engine.

Abstract: A fastener assembly for a gas turbine engine, and method of assembly, includes a first body having a first surface and a recess communicating through the first surface. The recess may be defined by a bottom surface and a side face spanning between the first and bottom surfaces. A shank of the assembly is generally engaged between the first body and a second body and includes opposite first and second end portions. The first end portion is located in the recess and the second end portion is engaged to the second body. A filler of the assembly is generally located in the recess to cover the first end portion. To reduce windage, the filler has an outer surface that is substantially flush with the first surface.

Abstract: Aspects of the disclosure are directed to systems and methods for receiving operating state parameters associated with an operative state of an aircraft, determining a clearance value between a first structure of the engine and a second structure of the engine, where the clearance value is determined based on the operating state parameters and a passive clearance model that includes a specification of an uncertainty in the clearance value, determining that the clearance value deviates from a clearance target in an amount that is greater than a threshold, and engaging an active clearance control (ACC) mechanism based on the deviation.

Abstract: Aspects of the disclosure are directed to an active clearance control system for an engine of an aircraft, comprising: a collector that is configured to receive a cooling fluid, at least two manifolds coupled to the collector, where a first of the manifolds is configured to receive at least a first portion of the cooling fluid from the collector and a second of the manifolds is configured to receive at least a second portion of the cooling fluid from the collector, and an insert coupled to the collector and the manifolds, where the insert is configured to seal an interface between the collector and the at least two manifolds over an operating range of the engine.

Abstract: Aspects of the disclosure are directed to systems and methods for receiving operating state parameters associated with an operative state of an aircraft, determining a clearance value between a first structure of the engine and a second structure of the engine, where the clearance value is determined based on the operating state parameters and a passive clearance model that includes a specification of an uncertainty in the clearance value, determining that the clearance value deviates from a clearance target in an amount that is greater than a threshold, and engaging an active clearance control (ACC) mechanism based on the deviation.

Abstract: The present disclosure relates to gas turbine engine and seal configurations, and components for a gas turbine engine. In one embodiment, a seal for a gas turbine engine includes a rotary seal element, the rotary seal element configured to rotate during operation of a gas turbine engine, and a stationary seal element having an annular seal surface. The stationary seal element includes a first area of the annular seal surface configured to engage with the rotary seal element, and the stationary seal element includes a second area of the annular seal surface configured to provide reduced resistance to the rotary seal element during a flight windmilling event.

Abstract: A fastener assembly for a gas turbine engine, and method of assembly, includes a first body having a first surface and a recess communicating through the first surface. The recess may be defined by a bottom surface and a side face spanning between the first and bottom surfaces. A shank of the assembly is generally engaged between the first body and a second body and includes opposite first and second end portions. The first end portion is located in the recess and the second end portion is engaged to the second body. A filler of the assembly is generally located in the recess to cover the first end portion. To reduce windage, the filler has an outer surface that is substantially flush with the first surface.