An anti-ice arrangement for a gas turbine engine may comprise an engine static structure, a fan blade housed for rotation within the engine static structure, and a magnetic field source mounted in close proximity to the fan blade and configured for inducing eddy currents in the fan blade to increase a surface temperature of the fan blade.

This invention concerns an aircraft propulsion system in which an engine has an engine core comprising a compressor, a combustor and a turbine driven by a flow of combustion products of the combustor. At least one propulsive fan generates a mass flow of air to propel the aircraft. An electrical energy store is provided on board the aircraft. At least one electric motor is arranged to drive the propulsive fan and the engine core compressor. A controller controls the at least one electric motor to mitigate the creation of a contrail caused by the engine combustion products by altering the ratio of the mass flow of air by the propulsive fan to the flow of combustion products of the combustor. The at least one electric motor is controlled so as to selectively drive both the propulsive fan and engine core compressor.

Herein provided are systems and methods for operating an aircraft engine during inclement weather. At least one image of a location substantially in line with a heading of the aircraft is acquired. Based on the at least one image, an inclement weather condition in the location is detected. An alert mode of the engine is triggered upon detecting the inclement weather condition. Responsive to the alert mode being triggered, at least one predetermined performance parameter of the engine is monitored. Upon detecting a change in the at least one predetermined performance parameter beyond a predetermined threshold, at least one operating condition of the engine is altered.

A condensation irradiation system is disclosed comprising an electromagnetic radiation emitter mounted on a locating structure, the locating structure being arranged in use to position the radiation emitter so as radiation emitted therefrom travels through a condensation detection region adjacent an upstream side of a gas turbine engine fan.

A method of mitigating contrails produced by an aircraft having a set of gas turbine engines, comprises the steps of (i) for each engine in a first subset of the engines, reducing the operating efficiency of the engine to produce a reduction in thrust provided by that engine and (ii) for each engine in a second subset, increasing the fuel flow to the engine to increase the thrust provided by that engine, the set of at least two gas turbine engines consisting of the first and second subsets. The method provides for contrail mitigation action by means of engine operating efficiency reduction to be directed to a first subset of engines for which contrail mitigation per unit engine operating efficiency reduction is greatest, the resulting reduction in thrust provided by such engines being at least partially compensated by increasing fuel flow to engines of the second subset.

A variable-geometry system for a gas turbine engine can be used to improve operations in various inclement weather conditions. This may be achieved by varying the orientation of an element in a gas turbine engine flowpath in response to a comparison between sensor-gathered parameter data and stored parameter values and ranges using a pre-programmed algorithm. The orientation of the element may be infinitely variable within a range of orientations.

This invention concerns an aircraft propulsion system in which an engine has an engine core comprising a compressor, a combustor and a turbine driven by a flow of combustion products of the combustor. At least one propulsive fan generates a mass flow of air to propel the aircraft. An electrical energy store is provided on board the aircraft. At least one electric motor is arranged to drive the propulsive fan and the engine core compressor. A controller controls the at least one electric motor to mitigate the creation of a contrail caused by the engine combustion products by altering the ratio of the mass flow of air by the propulsive fan to the flow of combustion products of the combustor. The at least one electric motor is controlled so as to selectively drive both the propulsive fan and engine core compressor.

A method and system for correlating engine thrust and engine thrust lever angle (TLA) during operation of a gas turbine engine powered aircraft is provided. The method includes: a) providing current flight conditions including a Mach number of the aircraft, altitude of the aircraft, and a TLA; b) determining a corrected fan speed value based on a sensed fan speed and flight conditions; c) determining a first corrected net thrust value based on the corrected fan speed value and the Mach number; d) determining a compensation factor using the corrected fan speed value, the Mach number, and the corrected net thrust value; e) determining a second corrected net thrust value as a function of the TLA; and f) correlating an engine fan speed to the TLA using the second corrected net thrust value as a function of the TLA and the compensation factor.

A method for determining an engine heath of an aircraft engine includes determining, by one or more control devices, the aircraft engine is operating in a bleed off condition; determining, by the one or more control devices, a first engine health modifier value while the aircraft engine is operating in the bleed off condition, the first of engine health modifier value including a compressor leakage flow value; determining, by the one or more control devices, a second plurality of engine health modifier values while the aircraft engine is operating in a bleed on condition; and determining, by the one or more control devices, an engine health parameter using at least one of the second plurality of engine health modifier values determined while the aircraft engine is operating in the bleed on condition and the compressor leakage flow value determined while the aircraft engine was operating in the bleed off condition.

A system for identifying timeframes for borescope inspections for a gas turbine engine, having: monitoring systems monitor engine conditions, derive engine condition information and communicate such information to processors; feature interpreter module electronically communicates (i) with processors to process engine condition information, and (ii) feature interpreter information to processors, such information defines a probability of a FOD event; accumulator module electronically communicates (i) with processors to processes feature interpreter information, stored information since a last borescope inspection, and (ii) accumulator information to processors, such information defines an accumulated probability of a FOD event; and predictor and inspection planner module electronically communicates (i) with processors to processes accumulator information and stored information defines a threshold limits for a probability of a FOD event, and (ii) predictor and inspection planner information to processors, such information identifies a timeframe for a next borescope inspections predicted to occur before a FOD event.