A gas turbine engine includes first and second structures secured to one another at a bolted flange joint. A seal is supported by a third structure. A cover is arranged over the bolted flange joint and discrete from the first and second structures. The cover provides a seal land that engages the piston seal and protects the first structure from the adverse thermal environment.

A gas turbine engine includes first and second structures secured to one another at a bolted flange joint. A seal is supported by a third structure. A cover is arranged over the bolted flange joint and discrete from the first and second structures. The cover provides a seal land that engages the piston seal and protects the first structure from the adverse thermal environment.

A method of operating a compoundable engine that includes a turbine having a turbine shaft and an intermittent internal combustion engine having an engine shaft. The engine shaft is rotated at a first rotational speed. The turbine is driven by exhaust gases of the intermittent internal combustion engine to rotate the turbine shaft while the engine shaft rotates independently from the turbine shaft. A rotatable load is driven with the turbine shaft. A rotational speed of the engine shaft is increased from the first rotational speed until the turbine shaft reaches a predetermined rotational speed. After the turbine shaft has reached the predetermined rotational speed, the rotational speed of the engine shaft is adjusted until the turbine shaft and the engine shaft are drivingly engageable with each other, and the turbine shaft with the engine shaft are engaged such that both are in driving engagement with the rotatable load.

A gas turbine engine according to an example of the present disclosure may include, among other things, a propulsor section including a propulsor having a plurality of propulsor blades, a geared architecture, a first spool including a first shaft that interconnects a first compressor and a first turbine, the first driving the propulsor through the geared architecture. The gas turbine engine is rated to provide an amount of thrust at ground idle, and the gas turbine engine is rated to provide an amount of thrust at maximum takeoff. A thrust ratio is defined as a ratio of the amount of thrust at ground idle divided by the amount of thrust at maximum takeoff. The thrust ratio can be less than or equal to 0.050.

A gas turbine engine according to an example of the present disclosure may include, among other things, a propulsor section including a propulsor having a plurality of propulsor blades, a geared architecture, a first spool including a first shaft that interconnects a first compressor and a first turbine, the first driving the propulsor through the geared architecture. The gas turbine engine is rated to provide an amount of thrust at ground idle, and the gas turbine engine is rated to provide an amount of thrust at maximum takeoff. A thrust ratio is defined as a ratio of the amount of thrust at ground idle divided by the amount of thrust at maximum takeoff. The thrust ratio can be less than or equal to 0.050.

An embodiment of a torch ignitor system for combustor of a gas turbine engine includes a torch ignitor, the torch ignitor having a combustion chamber oriented about an axis, the combustion chamber having axially upstream and downstream ends defining a flow direction through the combustion chamber, along the axis. The torch ignitor system also includes a cap defining the axially upstream end of the combustion chamber and oriented about the axis, wherein the cap is configured to receive a fuel injector and at least one glow plug, a tip at a downstream end of the combustion chamber, and a passage for pressurized oxygen containing gas passing through the cap from an exterior of the combustion chamber and in fluid communication with the combustion chamber. An embodiment of a method for starting a gas turbine engine is also disclosed.

An embodiment of a torch ignitor system for combustor of a gas turbine engine includes a torch ignitor, the torch ignitor having a combustion chamber oriented about an axis, the combustion chamber having axially upstream and downstream ends defining a flow direction through the combustion chamber, along the axis. The torch ignitor system also includes a cap defining the axially upstream end of the combustion chamber and oriented about the axis, wherein the cap is configured to receive a fuel injector and at least one glow plug, a tip at a downstream end of the combustion chamber, and a passage for pressurized oxygen containing gas passing through the cap from an exterior of the combustion chamber and in fluid communication with the combustion chamber. An embodiment of a method for starting a gas turbine engine is also disclosed.

A method comprising: spraying a ceramic coating to a substrate to a thickness of at least 5.0 mils (127 micrometers) without quench; and after the spraying, directing a carbon dioxide flow to a surface of the coating.

A method comprising: spraying a ceramic coating to a substrate to a thickness of at least 5.0 mils (127 micrometers) without quench; and after the spraying, directing a carbon dioxide flow to a surface of the coating.

A method of installing a retaining ring assembly in a turbine case is provided. The method may include installing a blade outer air seal into a case before installation of a retaining ring assembly. The method may further include installing a key system on a retaining ring to create the retaining ring assembly. The method may also include installing the retaining ring assembly in a case. The method may further include rotating the retaining ring assembly in the case until key system is aligned with a case slot. The method may also include tightening the key system to the retaining ring and cause key system to engage the case slot.