Abstract: A method for reducing a turbine clearance gap between a plurality of rotor blades of a turbine engine and a shroud of the turbine engine is provided. The method includes determining that an airplane is in a first flight condition, and adjusting the turbine clearance gap to a first clearance gap distance associated with the first flight condition. The method also includes determining a demand for a second flight condition, and adjusting an engine responsiveness to a first engine responsiveness for a first predetermined change in a power parameter of the engine. The method further includes reducing the engine responsiveness from the first engine responsiveness level to a second engine responsiveness level for a second predetermined change in the power parameter of the engine, and closing a clearance control valve associated with the shroud during the second predetermined change in the power parameter of the engine.

Abstract: A method for reducing a turbine clearance gap between a plurality of rotor blades of a turbine engine and a shroud of the turbine engine is provided. The method includes determining that an airplane is in a first flight condition, and adjusting the turbine clearance gap to a first clearance gap distance associated with the first flight condition. The method also includes determining a demand for a second flight condition, and adjusting an engine responsiveness to a first engine responsiveness for a first predetermined change in a power parameter of the engine. The method further includes reducing the engine responsiveness from the first engine responsiveness level to a second engine responsiveness level for a second predetermined change in the power parameter of the engine, and closing a clearance control valve associated with the shroud during the second predetermined change in the power parameter of the engine.

Abstract: A compressor blade having an airfoil that comprises oppositely-disposed convex and concave surfaces, oppositely-disposed leading and trailing edges defining therebetween a chord length of the airfoil, a forward-most nose of the airfoil located at the leading edge and having a profile, a blade tip, and an erosion-resistant coating. The coating is present on the concave surface near the trailing edge, optionally present on the nose, optionally present on the convex surface, wherein the convex surface is free of the erosion resistant coating within at least 20% of the chord length from the nose. The thickness of the coating on the concave surface, the convex surface, and the nose is such that, if the gas turbine engine is exposed to an erosive environment, deterioration of the concave surface, the convex surface and the leading edge does not form a pronounced cusp at an intersection of the convex surface and leading edge.

Abstract: A method for reducing a turbine clearance between a plurality of rotor blades of a turbine engine and a shroud of the turbine engine is provided. Said method includes determining, with a flight operation controller, that an airplane is in a first flight condition, wherein the first flight condition is associated with a first turbine clearance and a first engine responsiveness level, determining, with the flight operation controller, that the airplane is in a second flight condition, adjusting an engine responsiveness level from the first engine responsiveness level to a second engine responsiveness level based on determining the airplane is in the second flight condition, and adjusting the turbine clearance from the first turbine clearance to a second turbine clearance based on the engine responsiveness level.

Abstract: Erosion- and impact-resistant ceramic coatings suitable for protecting surfaces subjected to collisions with particles, including nominally round particles that typically inflict impact damage and more aggressive irregular-shaped particles that typically inflict erosion damage. The ceramic coating is formed to have one of three compositions: at least one layer of titanium aluminum nitride (TiAlN) having a thickness of about 25 to about 100 micrometers; multiple layers of chromium nitride (CrN) and TiAlN, each layer having a thickness of about 0.2 to about 1.0 micrometers to yield a total coating thickness of at least about 3 micrometers; and at least one layer of titanium silicon carbonitride (TiSiCN) having a thickness of about 15 to about 100 micrometers. The ceramic coating preferably has a total coating thickness of up to about 100 micrometers, and is deposited by a physical vapor deposition process to have a columnar and/or dense microstructure.

Abstract: A process for depositing coatings, and particularly erosion-resistant coatings suitable for protecting surfaces subjected to collisions with particles, such as a compressor blade of a gas turbine engine. The blade has an airfoil comprising oppositely-disposed convex and concave surfaces, oppositely-disposed leading and trailing edges defining therebetween a chord length of the airfoil, and a blade tip. An erosion-resistant coating is present on at least the concave surface, but not on the convex surface within at least 20% of the chord length from the leading edge.

Abstract: Erosion- and impact-resistant ceramic coatings suitable for protecting surfaces subjected to collisions with particles, including nominally round particles that typically inflict impact damage and more aggressive irregular-shaped particles that typically inflict erosion damage. The ceramic coating is formed to have one of three compositions: at least one layer of titanium aluminum nitride (TiAlN) having a thickness of about 25 to about 100 micrometers; multiple layers of chromium nitride (CrN) and TiAlN, each layer having a thickness of about 0.2 to about 1.0 micrometers to yield a total coating thickness of at least about 3 micrometers; and at least one layer of titanium silicon carbonitride (TiSiCN) having a thickness of about 15 to about 100 micrometers. The ceramic coating preferably has a total coating thickness of up to about 100 micrometers, and is deposited by a physical vapor deposition process to have a columnar and/or dense microstructure.

Abstract: A butterfly valve for a gas turbine engine includes a valve shaft and a valve disk. The valve disk has a centerline axis that extends through the valve disk. The valve disk also includes a shaft opening, an outer periphery, an outer surface, a first side, and a second side. The first side is opposite the second side. The shaft opening extends through the valve disk adjacent the centerline axis, and is sized to receive the valve shaft therein. The disk outer surface extends over the first and second sides, and is tapered between the outer periphery and the centerline axis over at least one of the disk first and second sides.

Abstract: A butterfly valve for a gas turbine engine includes a valve shaft and a valve disk. The valve disk has a centerline axis that extends through the valve disk. The valve disk also includes a shaft opening, an outer periphery, an outer surface, a first side, and a second side. The first side is opposite the second side. The shaft opening extends through the valve disk adjacent the centerline axis, and is sized to receive the valve shaft therein. The disk outer surface extends over the first and second sides, and is tapered between the outer periphery and the centerline axis over at least one of the disk first and second sides.