Abstract: A cooling system for providing a buffer cooled cooling air to a turbine section of a gas turbine engine is disclosed. The cooling system may comprise a first conduit configured to transmit a cooling air toward the turbine section, a heat exchanger configured to cool a bleed airflow diverted from the first conduit to provide a buffer air, and a bypass conduit configured to direct at least a portion of the buffer air through at least one passageway that bypasses a bearing compartment of the gas turbine engine. The cooling system may further comprise a manifold configured to allow the cooling air exiting the first conduit and the buffer air exiting the bypass conduit to mix and provide the buffer cooled cooling air, and a nozzle assembly configured to deliver the buffer cooled cooling air to the turbine section.

Abstract: Aspects of the disclosure are directed to an assembly associated with an engine of an aircraft, comprising a bolt comprising at least one groove, and at least one seal seated within the at least one groove, where the at least one seal is configured to seal radially against a counter bore that the bolt is coupled to. Aspects of the disclosure are directed to a bolt comprising a head, a first groove formed in a first side of the head and configured to seat a first seal, and an internal feature formed in the head and interfacing with a surface of the head, where the internal feature is configured to enable the bolt to be tightened.

Abstract: A cooling system for providing a buffer cooled cooling air to a turbine section of a gas turbine engine is disclosed. The cooling system may comprise a first conduit configured to transmit a cooling air toward the turbine section, a heat exchanger configured to cool a bleed airflow diverted from the first conduit to provide a buffer air, and a bypass conduit configured to direct at least a portion of the buffer air through at least one passageway that bypasses a bearing compartment of the gas turbine engine. The cooling system may further comprise a manifold configured to allow the cooling air exiting the first conduit and the buffer air exiting the bypass conduit to mix and provide the buffer cooled cooling air, and a nozzle assembly configured to deliver the buffer cooled cooling air to the turbine section.