A method includes obtaining a first test matrix for a first aircraft system and a second test matrix for a second aircraft system. The method also includes, during a first operational test of the first test matrix, obtaining sensor data that includes second sensor data that is not specified by the first test matrix. The method includes evaluating a second operational test of the second test matrix by processing the second sensor data using a second analytic model of the second aircraft system. The method also includes generating second predicted sensor data based on the evaluation of the second operational test. The method includes generating a second error measure by comparing a second subset of the sensor data to the second predicted sensor data. The method includes determining, based at least in part on a range of the second sensor data, a test coverage metric of the second test matrix.

The present disclosure provides a device for controlling a variable section ejection nozzle of a turbojet engine nacelle of an aircraft. The device includes a calculator adapted to determine a position setpoint of the nozzle and a management system of the servo-control of the position of the variable nozzle depending on the flow rate of the fuel supplying the turbojet engine. The management system includes at least one instantaneous flow rate sensor of the fuel and a management unit which is designed to compare the flow rate measured by the flow rate sensor with a theoretical fuel flow rate depending on the parameters of the flight of the aircraft, to determine a correction value of the position of the nozzle depending on the comparison of the measured flow rate and the theoretical fuel flow rate, and to correct the position setpoint of the nozzle according to the correction value.

A method and system for establishing sets of blade frequency values for each rotating blade of a rotor assembly at two or more different points in time and determining an indication of blade health from the change in the blade frequency values is provided. Blade frequency values are determined by receiving measurements of vibratory responses from blade monitoring equipment (20) and processing via a processing device (30) vibration data as a system of rotating blades to extract a frequency of each blade. Sets of blade frequency values are compared to determine a change in the blade frequency values for each rotating blade to provide the indication of blade health.

A method for monitoring cold start of Brayton cycle power generation system comprises: measuring an ambient temperature to obtain a Brayton cycle predetermined operating line of a working fluid, parameter values and calculated values of three monitoring points of the Brayton cycle predetermined operating line, and a position of a saturation curve of the working fluid according to the ambient temperature and a LUT; starting the cold start, continuously measuring the parameter values of the three monitoring points, and meanwhile continuously recording and displaying moving trajectories of the parameter values and the calculated values of the three monitoring points; after the parameter values and the calculated values of the three monitoring points are close to the default values, operating the Brayton cycle power generation system for a predetermined time; and ending the cold start, to enter a stable operating state of the Brayton cycle power generation system.

An aspect includes a system for a gas turbine engine. The system includes one or more bleeds of the gas turbine engine and a control system configured to check one or more activation conditions of a dirt rejection mode in the gas turbine engine. A bleed control schedule of the gas turbine engine is adjusted to extend a time to hold the one or more bleeds of the gas turbine engine partially open at a power setting above a threshold based on the one or more activation conditions. One or more deactivation conditions of the dirt rejection mode in the gas turbine engine are checked. The dirt rejection mode is deactivated to fully close the one or more bleeds based on the one or more deactivation conditions.

Methods and systems for measuring an axial position of a rotating component of an engine are described herein. The method comprises obtaining a signal from a sensor coupled to the rotating component, the rotating component having a plurality of position markers distributed about a surface thereof, the position markers having an axially varying characteristic configured to cause a change in a varying parameter of the signal as a function of the axial position of the rotating component. Based on the signal, the method comprises determining a rotational speed of the rotating component from the signal, determining the varying parameter of the signal, and finding the axial position of the rotating component based on a known relationship between the axial position, the rotational speed, and the varying parameter of the signal.

In an embodiment, a rotorcraft includes: a plurality of engines; a flight control computer connected to the plurality of engines, the flight control computer being configured to: receive an operating parameter of a first engine of the plurality of engines; determine an engine output ramping rate for the first engine according to a difference between the operating parameter of the first engine and a nominal limit of the first engine; and increase the output of the first engine in response to detecting an outage of another engine of the plurality of engines, the output of the first engine being increased according to the engine output ramping rate.

A fuel supply control device controls a fuel supply pump based on a front-rear differential pressure across a metering valve for a fuel supply amount, which is detected by a differential pressure gauge, using parallel flow passages of an orifice and a pressurizing valve as the metering valve, in which the fuel supply control device includes a first control amount generation unit generating a first control amount based on the front-rear differential pressure, a second control amount generation unit generating a second control amount based on the rotation speed of the fuel supply pump, a control amount selection unit, a subtractor, and a control calculation unit, in which the control amount selection unit selects the first control amount in a case where the rotation speed is equal to or lower than a predetermined threshold and select the second control amount in a case where the rotation speed exceeds the threshold.

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 including the nvPM content of the exhaust. Also disclosed is a fuel characteristic determination system, a method of operating an aircraft, and an aircraft.

A method for tuning a gas turbine engine includes performing a sensitivity step process on a tuning parameter. An operating parameter is monitored. The gas turbine is operating in a first operational state and the operating parameter has an initial condition. The tuning parameter is selected for adjustment. The tuning parameter is adjusted by a predefined amount. The adjustment includes applying an incremental bias adjustment to a fuel flow fraction schedule. The gas turbine engine transitions to a second operational state, wherein the operating parameter has an adjusted condition. The adjusted condition and the initial condition of the operating parameter are applied to a cost function. It is then determined that the cost function results in a cost function value indicative of a decreased cost. The incremental bias adjustment and the cost function value is written to a bias look-up table and are associated with the selected tuning parameter.