A blade damage evaluation apparatus includes: a registration unit for design information of a turbine and maintenance information; an acquisition processor for detection data of sensors; a first discrimination processor for first facility states of the turbine at a plurality of past time points; a classification processor for classes C.sub.n of a plurality of first facility states; a first determination processor for first operating state values of the turbine; another registration unit for first damage rates at past time points; a setting processor of a characteristic function for each of the classes C.sub.n; a second discrimination processor for a second facility state of the turbine at the current time point; a second determination processor for a second operating state value of the turbine at the current time point; and an analyzer for a second damage rate at the current time point.

A method of repairing a rod guide assembly of a fuel control unit of an aircraft engine is provided. The method comprises disconnecting a used spring seat from the rod of the rod guide assembly and welding a replacement spring seat to the rod using an electron beam controlled using a circular beam deflection pattern.

A method of providing an engine family includes providing a first engine having a low pressure turbine driving a low pressure compressor at a first speed ratio, and a high pressure turbine driving a high pressure compressor. The method includes providing a second engine by changing the first speed ratio of the first engine to a second speed ratio.

A system can include a gas turbine and a processing system. The gas turbine can include a compressor coupled to a turbine through a shaft. The processing system can be configured to: automatically transition an operating condition of the system through a plurality of operating states; determine an efficiency of the system at each of a plurality of the operating states; for each of the plurality of operating states: select a future operating state of the system based on the determined efficiency of the current operating state.

A method for installing a gas turbine assembly of a first type at a position of an existing power plant where previously a gas turbine assembly of a second type was installed on a foundation specially designed for said second type. The gas turbine assembly includes at least one housing, a compressor, a combustion chamber, a gas turbine, and a plurality of venting and removal lines guided along the exterior of the housing. Modifications to the venting and/or removal lines of the gas turbine assembly of the first type are carried out in a first step, and the modified gas turbine assembly is installed on the existing foundation in a second step.

An aircraft turbomachine, including a fan that is able to rotate inside a casing, and an electric machine including a rotor secured to the fan and a stator secured to the casing, wherein the rotor of the electric machine includes a ring that is able to rotate inside the stator, which is linked by arms to a cone mounted upstream from the fan.

A flexible metal foil can be fixed on the inside part of a variable pitch vane control ring of a turbojet compressor, so as to close all through holes in which lever pins and their surrounding bushes are housed. As a result, the foil can retain the shank of the bush if the bush breaks. The use of such foil does not impose the development of a new model of control ring and its impact on the mass is small enough so that it does not affect engine performances. Therefore it avoids problems related to the breakage of bushes without having to make major changes to the existing system.

The present invention is directed to in situ methods for maintaining turbine assemblies. One such method includes: disposing a maintenance apparatus on the rotor; positioning the maintenance apparatus proximate to the damaged region by rotating the rotor; and repairing the damaged region by operating a repair tool disposed on the apparatus. Another method includes: disposing a maintenance apparatus on the stator; positioning the damaged region proximate to the maintenance apparatus by rotating the rotor; and repairing the damaged region by operating a repair tool disposed on the apparatus.

A coupon for replacing a cutout in a hot gas path component of a turbomachine is provided. In one embodiment, the coupon includes a body having an outer surface; and a plurality of grinding depth indicators in the outer surface of the body. In another embodiment, the coupon includes a body having an edge periphery configured to mate with an edge periphery of the cutout, and at least a portion of the edge periphery of the body has a wall thickness greater than a wall thickness of an edge periphery of the cutout. The embodiments may be used together or separately.

A coupon for replacing a cutout in a hot gas path component of a turbomachine is provided. The coupon includes a body having an outer surface; a chamber within the body for receiving a flow of a coolant; and a passage extending from the chamber to the outer surface of the body. The passage includes an internal portion within a wall of the body having a first perpendicular, cross-sectional area and an exit portion at the outer surface of the body having a second perpendicular, cross-sectional area that is greater than the first perpendicular, cross-sectional area.