The present application discloses a method of determining one or more fuel characteristics of an aviation fuel suitable for powering a gas turbine engine of an aircraft. The method comprises: determining, during use of the gas turbine engine, one or more exhaust content parameters by performing a sensor measurement on an exhaust of the gas turbine engine; and determining one or more fuel characteristics of the fuel based on the one or more exhaust parameters. Also disclosed is a fuel characteristic determination system, a method of operating an aircraft, and an aircraft.

Turbines and associated equipment are normally cleaned via water or chemical pressure washing via a mist, spray systems. However, these systems fail to reach deep across the gas path to remove fouling materials. Various embodiments herein pertain to apparatus and methods that utilize the water and exiting chemicals to generate a foam. The foam can be introduced at that gas-path entrance of the equipment, where it contacts the stages and internal surfaces to contact, scrub, carry, and remove fouling away from equipment to restore performance.

A state quantity acquisition unit acquires a state quantity of a target apparatus including a temperature of the target apparatus. A load specification unit specifies a load history of the target apparatus, based on the state quantity. A remaining life calculation unit calculates a parameter related to a remaining life of the target apparatus for each of a plurality of degradation types, based on the load history specified by the load specification unit.

A system and method of using a tool assembly is provided. The system includes a body, a first camera and a second camera fixed to the body, and a controller. The controller is configured to receive data indicative of images of a reference feature from the first camera, determine data indicative of a first spatial position of the first camera based at least in part on the received data indicative of the images of the reference feature, and determine data indicative of a second spatial position of the second camera based on the first spatial position, a known spatial relationship between the first location and the second location, or both. Further, the controller may be configured to receive data indicative of images of a target feature using the second camera, derive dimensions of the target feature based on the images, and generate a three-dimensional representation of the target feature.

A system and a method for configuring at least one variable geometry mechanism (VGM) of an aircraft engine are provided. Pass-off testing data for the aircraft engine is obtained, the pass-off testing data indicative of an actual value of at least one operating parameter of the aircraft engine. Based on the pass-off testing data, at least one trim value to be used to adjust a setting of the at least one VGM to bring the actual value of the at least one operating parameter towards a target value is determined, a running line of the aircraft engine being substantially constant when the actual value of the at least one operating parameter is at the target value. The setting of the at least one VGM is adjusted, during pass-off testing of the aircraft engine, using the at least one trim value.

A method for creating a three-dimensional (3D) mark in a protective coating including at least one of a TBC and a bond coating over a metal part, is provided. The method may include positioning a mask over the protective coating, the mask including an opening pattern therein; and performing an abrasive waterjet process on the protective coating using the mask. The abrasive waterjet erodes a first portion of the protective coating exposed through the first opening pattern to create the 3D mark. The mask is removed, leaving the 3D mark in the protective coating. The 3D mark only partially penetrates through the protective coating. A metal part may include a metal body, a protective coating over the metal body, and the 3D mark in the protective coating, is also provided. The 3D mark in the protective coating may include an opening having a width of between 30 and 300 micrometers.

Methods and systems for detecting an abnormal start of a gas turbine engine are described. Speed data points are sampled from a sensor associated with the engine in accordance with a sampling rate, the speed data points being indicative of a rotational speed of a gas generator of the engine during engine start. The speed data points are continuously stored during the engine start. Previously-obtained speed data points which are older than an abnormal start delay are discarded. An abnormal engine start event is detected by comparing a first one of the stored speed data points with a second one of the stored speed data points, the second one of the stored speed data points obtained before the first one.

A method of maintaining at least one gas turbine engine includes monitoring a compressor of the gas turbine engine. The compressor includes a compressor case at least partially defining a flow path, a plurality of stages and a vane actuator system configured to move at least one of the stages. The vane actuator system includes a vane mover having one or more slots formed therein and configured to actuate the at least one stage. The vane mover may be replaced after the gas turbine engine has experienced engine degradation.

Method for monitoring a turbomachine comprising a stator and a rotor, device, system, aircraft and computer program product. The method comprises a step of acquiring an input signal which represents a deformation of the stator or rotor of the turbomachine. The input signal has been acquired by a deformation gauge which is attached to the stator or rotor. The input signal comprises a first component which represents deformations of the stator or rotor which are caused by rotation of the rotor vanes in relation to the stator, and a second component which represents deformations which are caused by different elements of the rotor vanes. The method comprises a step of re-sampling the input signal in order to obtain a re-sampled input signal comprising a predefined whole number of samples per revolution of the turbomachine rotor. The method also comprises a step of processing the re-sampled input signal, comprising: filtering the re-sampled input signal, making it possible to acquire a filtered input signal in which the second component is attenuated, and separating the filtered input signal into a plurality of third components, each third component representing a contribution to the deformation caused by a respective associated vane. The method also comprises a step of detecting, in a third component, contact between the vane associated with the third component and the stator.

A method is provided for an engine. During this method, a database is provided for a parameter of the engine. The database includes a plurality of values for the parameter determined over a period of time. Confidence bands are established using a probability density function on the database. An action is performed in response to a comparison of a first updated value for the parameter to the confidence bands. The engine may be configured as a gas turbine engine or another type of heat engine.