A method, apparatus, system, and computer program product for managing pumps in an aircraft. Flight information about an operation of the pumps in a pump package in the aircraft is received by a computer system. The flight information is received from the aircraft. A number of times that an abnormal switching occurred for the pumps within a window of consecutive flights is determined by the computer system when the abnormal switching is identified from the flight information. A set of actions is performed by the computer system when the abnormal switching occurred a number of times for the pumps within the window of consecutive flights that exceeds a set of thresholds for the abnormal switching that is considered healthy for the pumps.

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.

The present application discloses a method of determining one or more fuel characteristics of an aviation fuel used for powering a gas turbine engine of an aircraft. The method comprises: determining one or more performance parameters of the gas turbine engine during a first time period of operation of the gas turbine engine; and determining one or more fuel characteristics of the fuel based on the one or more performance parameters. A method of operating an aircraft, a fuel characteristic determination system, and an aircraft are also disclosed.

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.

A method is used for determining an operating point of a compressor that includes at least one impeller, compressor blades attached to the impeller, a housing and at least two sensors. The method includes calculating a deflection of the compressor blades. An operating point and a surge margin with respect to a surge limit are determined based on the calculating of the deflection by measuring passage times of the compressor blades at a sensor. A signal that is representative of a rotation speed is determined and is associated with the compressor impeller. In a learning or adaptation mode, compressor blade-specific, state-induced and position-induced deviations from an ideal state are determined using compressor blade-specific passage times that are measured and compared with ideal passage times. In a working mode, compressor blade-specific passage times are measured and the compressor blade-specific passage times are corrected using the determined state-induced and position-induced deviations.

Systems and methods for turbomachine control based upon magnetostrictive sensor measurements are provided. A turbomachine (e.g., a compressor) can be instrumented with at a sensor configured to measure an operating parameter, and a magnetostrictive sensor configured to acquire a torsional measurement (e.g., torsional vibration and/or torque) of a turbomachine shaft. An analyzer can receive the operating parameter measurement and torsional measurement and determine an updated operating parameter limit and/or an updated exclusion zone based upon the torsional measurement for control of the operating parameter.

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.

A control system for a variable area fan nozzle (VAFN) is disclosed. The VAFN may have a plurality of petals and may be for use with a gas turbine engine. The control system may include a primary system configured to acquire primary data indicative of an operating condition of the VAFN, a secondary system configured to acquire secondary data indicative of a current operating condition of the gas turbine engine, and a control module in operative communication with the primary system and the secondary system. The control module may be configured to: determine a nozzle area of the VAFN based at least in part on the primary data, adjust the determined nozzle area based on the secondary data, and position the plurality of petals according to the adjusted nozzle area.

There is provided a rotor bow mitigation system and method for an aircraft engine. At least one value of at least one engine parameter prior to a shutdown of the engine is obtained, the at least one engine parameter comprising a first temperature internal to the engine. A second temperature external to the engine is measured and a motoring duration and a motoring interval for the engine are determined based on at least the first temperature and on the second temperature. Upon detecting a start indication for the engine, the engine is motored for the motoring duration and at the motoring interval.

To sensing an anomaly on the basis of a multi-dimensional time series sensor signal, in order to determine the next action for a countermeasure, survey, or the like, the present invention is configured such that a multi-dimensional feature vector for each time is extracted on the basis of a sensor signal, a reference feature vector for each time is extracted on the basis of a set of characteristic vectors for a predetermined learning period and the characteristic vector of each time, an anomaly measure is calculated on the basis of the difference between the feature vectors for the times and the reference feature vectors, an anomaly is detected by comparing the anomaly measure and a predetermined threshold value, and the anomaly-related sensor for the time the anomaly is detected is identified on the basis of a 2-dimensional distribution density of feature values.