Methods and systems for starting an aircraft gas turbine engine are described. The method comprises, in a first phase of a startup upon receipt of a start request, modifying a first set of engine control parameters to cause light-up; in a second phase of the startup, modifying a second set of engine control parameters to set conditions for light-around; and in a third phase of the startup, modifying a third set of engine control parameters to propagate a flame around a combustor of the gas turbine engine.

Provided area second-order sliding mode observation-based fan power control method and system. The method includes: calculating, by second-order sliding mode observation, an observed rotational speed value of a fan, and calculating a maximum power reference current corresponding to maximum power of the fan according to a relational expression between the rotational speed and maximum power point; and performing, by controlling a Pulse Width Modulation (PWM) switch to be toggled, system Maximum Power Point Tracking (MPPT) according to the maximum power reference current, so as to control the fan to operate stably at the maximum power point.

Systems and methods for optimizing clearances within an engine include an adjustable coupling configured to couple a thrust link to the aircraft engine, an actuator coupled to the adjustable coupling, where motion produced by the actuator adjusts a hinge point of the adjustable coupling, sensors configured to capture real time flight data, and an electronic control unit. The electronic control unit receives flight data from the sensors, implements a machine learning model trained to predict clearance values within the engine based on the received flight data, predicts, with the machine learning model, the clearance values within the engine based on the received flight data, determines an actuator position based on the clearance values, and causes the actuator to adjust to the determined actuator position.

A plant monitoring device (20) is provided with: a state quantity acquiring unit (211) which acquires state quantities for each of a plurality of characteristic items relating to a plant; an abnormality degree calculating unit (212) which calculates a degree of abnormality representing a degree of approach toward an abnormal side relative to a limit value that is predetermined for each characteristic item, for the state quantities acquired at a plant monitoring timing; a distance calculating unit (213) which uses a statistical technique to calculate distances representing the degrees of separation, from the normal operating state of the plant, of the state quantity and the degree of abnormality acquired at the monitoring timing; and a determining unit (214) which determines the operating state of the plant on the basis of the calculated distances.

Methods and systems for starting an aircraft gas turbine engine are described. The method comprises, in a first phase of a startup upon receipt of a start request, modifying a first set of engine control parameters to cause light-up; in a second phase of the startup, modifying a second set of engine control parameters to set conditions for light-around; and in a third phase of the startup, modifying a third set of engine control parameters to propagate a flame around a combustor of the gas turbine engine.

Methods and systems for operating a rotorcraft comprising a plurality of engines are provided. A request to enter into an asymmetric operating regime (AOR), in which at least one active engine of the plurality of engines is operated in an active mode to provide motive power to the rotorcraft and at least one standby engine of the plurality of engines is operated in a standby mode to provide substantially no motive power, is obtained. Engine usage data for the plurality of engines, including at least one first engine and at least one second engine, is determined. Based on the engine usage data, one of the at least one first and second engines is operated as the at least one active engine for the AOR, and the other one of the at least one first and second engines is operated as the at least one standby engine for the AOR.

Systems and method for filling a fuel manifold comprising at least a primary and a second manifold of a gas turbine engine are described. The method comprises providing fuel flow to the secondary manifold of the gas turbine engine, the secondary manifold being partly or completely empty; monitoring at least one engine operational parameter of the gas turbine engine as fuel fills the secondary manifold; and accelerating the engine when a transition threshold is reached, the transition threshold being associated with the engine operational parameter and indicative that fuel has reached the combustor.

A method for qualifying a gas turbine engine component includes creating a first set of substantially identical gas turbine engine components via a uniform manufacturing procedure, determining a set of as-manufactured parameters of each gas turbine engine component in the first set, and determining a variance model of the first set. The variance model includes a representative parameter profile, which includes a plurality of component parameter profiles. The sum of each of the component parameter profiles is the representative parameter profile. The method also includes determining at least one predicted response models based at least in part on the variance model, identifying as-manufactured parameters of a second engine component, applying the as-manufactured parameters of the second engine component to the at least one predicted response models, thereby generating a predicted response output, and qualifying the second engine component for usage in at least one gas turbine engine corresponding to the at least one predicted response model.

A method for operating a turbine engine is provided. The method includes receiving operating data comprising at least an engine operation parameter, an environmental parameter, a location parameter, and a time parameter; operating the turbine engine based on a baseline ground operation schedule; generating an adjusted ground operation schedule based on the operating data and the baseline ground operation schedule, wherein generating the adjusted ground operation schedule is based on a machine learning algorithm; and operating the engine based on the adjusted ground operation schedule.

A qualification system for gas turbine engine components includes a computer system configured to receive a set of measured parameters for each gas turbine engine component in a plurality of substantially identical gas turbine engine components, and determine a variation model based on the set of measured parameters. The computer system includes at least one simulated engine model configured to determine a predicted operation of each gas turbine engine component in the plurality of substantially identical gas turbine engine components, a correlation system configured to correlate variations in the set of parameters for each of the gas turbine engine components with a set of the predicted operations of each gas turbine engine, thereby generating a predictive model based on the variations. The computer system also includes a qualification module configured to generate a qualification formula based on the predictive model. The qualification formula is configured to receive a set of measured parameters of an as-manufactured gas turbine engine component and determine when the as manufactured gas turbine engine component is qualified for inclusion in at least one engine.