Abstract: A method of operating a multi-engine system of an aircraft having first and second engines includes accumulating compressed air in a pressure vessel external to the engines, and operating the first and second engines asymmetrically, by controlling the first engine to operate in an active operating condition providing sufficient power and/or rotor speed for demands of the aircraft, and controlling the second engine to operate in a standby operating condition wherein the second engine produces less power output than the first engine. In response to a power demand request, the second engine is accelerated out of the standby operating condition by introducing therein compressed air from the pressure vessel at a location upstream of a combustor of the second engine.

Abstract: Lubricant pump systems and associated methods for aircraft engines are provided. The method includes receiving an input torque, dividing the input torque between a first load path receiving a first portion of the input torque, and a second load path receiving a second portion of the input torque. A first lubricant pump of the aircraft engine is driven via the first load path using the first portion of the input torque. A second lubricant pump of the aircraft engine is driven via the second load path using the second portion of the input torque. When a malfunction of the second lubricant pump occurs, the method includes ceasing to drive the first lubricant pump and the second lubricant pump using the input torque.

Abstract: An assembly is provided for a turbine engine. This turbine engine assembly includes a static structure, a conduit and a bracket. The static structure includes a port. The conduit extends longitudinally through the port. The bracket couples the conduit to the static structure. The bracket includes a first base mount, a second bade mount, a conduit mount, a first damper and a second damper. The first base mount is attached to the static structure. The second base mount is attached to the static structure. The conduit mount is mechanically coupled with the conduit. The first damper is between the first base mount and the conduit mount. The second damper is between the second base mount and the conduit mount.

Abstract: The gas turbine intake can have a swirl housing having an inlet portion fluidly connecting an exhaust conduit, an annular outlet defined around a central axis and fluidly connecting a turbine gas path, a swirl path extending circumferentially around the central axis from the inlet portion to a circumferential outlet, the circumferential outlet fluidly connected back into the inlet portion, and vanes located in the swirl housing, the vanes circumferentially interspaced from one another relative the central axis and located radially inwardly from the swirl path relative the central axis, the swirl path being free of the vanes.

Abstract: An orifice pack is provided for delivering pressurized air to a compressor bleed valve of a gas turbine engine. The orifice pack has a diffusion chamber in serial flow communication with a tapering passage and a first outlet passage for venting a first portion of the pressurized air from the diffusion chamber. A second outlet passage branches off from the diffusion chamber at an axial location between the inlet and the tapering passage. The second outlet passage is fluidly connected to the compressor bleed valve for directing a second portion of the pressurized air from the diffusion chamber to the compressor bleed valve.

Abstract: An electronic controller for an engine and a propeller, a control system and related methods are described herein. The control system comprises the controller having a first channel and a second channel independent from and redundant to the first channel. Each channel comprises a control processor configured to receive first engine and propeller parameters and to output, based on the first engine and propeller parameters, at least one engine control command and at least one propeller control command. Each channel also comprises a protection processor configured to receive second engine and propeller parameters and to output, based on the second engine and propeller parameters, at least one engine protection command and at least one propeller protection command. The control system comprises sensors for measuring the parameters of the engine and/or the propeller and effectors configured to control the engine and the propeller.

Abstract: An aircraft has an exhaust duct assembly disposed in a low-pressure turbine portion of a gas turbine engine to discharge exhaust gas to the outside and includes a duct having an inlet through which an exhaust gas is introduced, an exhaust portion through which the exhaust gas is exhausted, and a mounting bore formed therethrough; a duct housing in which the duct is disposed therein, and including a mounting hole into which the exhaust portion is inserted; a shaft housing disposed inside the mounting bore, inserted into the duct housing so that one end thereof faces the inlet of the duct, and having a driving axis of the low-pressure turbine portion disposed therein; and a sealing portion having a ring shape, being coupled to one end of the shaft housing, and maintaining airtightness between the driving axis and the shaft housing.

Abstract: Methods and systems of operating a gas turbine engine in a low-power condition are provided. In one embodiment, the method includes supplying fuel to the combustor by supplying fuel to the first fuel manifold via a first flow divider valve and supplying fuel to the second fuel manifold via a second flow divider valve. While supplying fuel to the combustor by supplying fuel to the first fuel manifold, the method includes stopping supplying fuel to the second fuel manifold and supplying pressurized gas to the second fuel manifold via the second flow divider valve to flush fuel in the second fuel manifold into the combustor and hinder coking in the second fuel manifold and associated nozzles.

Abstract: The present disclosure relates to a housing for an engine component. The housing comprises a wall made of a light alloy. An epoxy primer coating having at least one layer of a primer containing at least 80 wt. % epoxy covering the wall. An intumescent paint coating having at least one layer of intumescent paint directly covering the epoxy primer. And, an epoxy top coat directly covering the intumescent paint coating, the epoxy top coat having at least one layer of a top coat containing at least 80 wt. % epoxy.

Abstract: In accordance with at least one aspect of this disclosure, a fluid system of an aircraft includes a primary fluid conduit that conveys a primary fluid, and a leak detection system disposed around at least a portion of the primary fluid conduit and forming one or more detection volumes. The leak detection system determines whether there is a primary fluid leak into the one or more detection volumes by sensing a pressure change in the one or more detection volumes.

Abstract: An article has a nickel-based alloy substrate having, in weight percent: 5.4-7.4 Re; 4.1-5.9 Ru; 3.0-6.2 Cr; 3.0-10.0 Co; 0.5-3.8 Mo; 3.0-6.0 W; 4.6-8.6 Ta; 5.0-6.4 Al; 0.050-0.30 Hf; no more than 0.50 all other elements, if any, individually; and no more than 2.0 all other elements, if any, combined. A nickel-based coating is on the substrate and comprising, in weight percent: 6.0-10.0 Al; 4.0-15.0 Cr; 11.0-15.0 Co; 0.1-1.0 Hf; 0.1-1.0 Si; 0.1-1.0 Y; up to 1.0 Zr if any; up to 7.0 Ta if any; up to 6.0 W if any; no more than 1.0 all other elements, if any, individually; and no more than 4.0 all other elements, if any, combined.

Abstract: A multi-rotor electric machine having a stator, a first rotor magnetically coupled to the stator and a second rotor magnetically coupled to the stator is disclosed. A method of operating the electric machine comprises driving a gear via a first face of the gear using the first rotor and driving the gear via a second face of the gear using the second rotor.

Abstract: Methods and systems for characterizing holes in a combustor liner of a gas turbine engine, and associated repair methods are provided. One method comprises receiving first measured data of the combustor liner in an uncoated state. The method includes determining a first location and a first orientation of a first hole and a first location and a first orientation of a second hole in the combustor liner using the first measured data. The method includes receiving second measured data of the combustor liner in a coated state where the second hole is at least partially obstructed by a coating and the first hole is substantially unobstructed by the coating. The method includes inferring a second location of the second hole of the combustor liner in the coated state using a known spacing between the first location of the first hole and the first location of the second hole. The characterization of the holes may be used to re-drill the obstructed second hole.

Abstract: An aircraft engine includes an air inlet duct and at least one strut having a leading edge and a trailing edge. The at least one strut extends across at least part of the air inlet duct and has a strut passage. The trailing edge has one or more edge contours, each defining a contour edge wall recessed from a baseline surface of the trailing edge. The one or more edge contours have a recessed tap in fluid communication with the strut passage.

Abstract: A diffuser nozzle for a gas turbine engine includes a housing disposed about a nozzle axis and extending between a first nozzle end and a second nozzle end. The housing defines a nozzle duct. A plurality of walls is disposed within the nozzle duct. The plurality of walls subdivides the nozzle duct into a plurality of duct sections. The plurality of walls further defines a plurality of axially-extending duct segments of the nozzle duct such that within a first axially-extending duct segment, the duct cross-sectional area of a first duct section of the plurality of duct sections is greater than the duct cross-sectional area of each other duct section and within a second axially-extending duct segment, the duct cross-sectional area of a second duct section of the plurality of duct sections is greater than the duct cross-sectional area of each other duct section.

Abstract: There is provided a blade angle feedback system for an aircraft-bladed rotor rotatable about a longitudinal axis and having an adjustable blade pitch angle. A feedback device is coupled to rotate with the rotor and to move along the axis with adjustment of the blade pitch angle. The feedback device comprises a body having position marker(s) embedded therein, the body made of a first material having a first magnetic permeability and the position marker(s) comprising a second material having a second magnetic permeability greater than the first. Sensor(s) are positioned adjacent the feedback device and configured for producing, as the feedback device rotates about the axis, sensor signal(s) in response to detecting passage of the position marker(s). A control unit is communicatively coupled to the sensor(s) and configured to generate a feedback signal indicative of the blade pitch angle in response to the sensor signal(s) received from the sensor(s).

Abstract: An aircraft engine includes a core gas path through which a core gas flow flows, an exhaust duct receiving the core gas flow, an air-cooled heat exchanger disposed in a heat exchanger duct having an air inlet providing cooling air to the air-cooled heat exchanger and an air outlet in fluid communication with the exhaust duct, and a cover disposed in the heat exchanger duct downstream of the air-cooled heat exchanger. The cover is movable between an open position, in which the cover allows the cooling air to flow through the air outlet into the exhaust duct, and a closed position, in which the cover substantially blocks the air outlet. The cover is operable to move from the open position to the closed position at a predetermined temperature of the cover.

Abstract: A combustor includes a combustor liner defining a combustion chamber and a fuel and air mixing body connected to the combustor liner to deliver mixed fuel and air into the combustion chamber. The mixing body includes an inner housing member centered on a center axis and an intermediate housing member. A mixing passage is defined between the inner and intermediate housing members. The mixing passage extends along a direction from an upstream end to a downstream end with a circumferential component, a component in an axially downstream direction, and a radially inward component with at least one air inlet into the mixing passage. A fuel supply extends into the mixing passage at a location downstream of the air inlet. The mixing passage extends downstream to supply fuel and air into the combustion chamber. A gas turbine engine is also disclosed.

Abstract: An aircraft power plant has a hybrid propulsion system having an electric motor, an output shaft drivingly connectable to a thrust generator, a combustion engine, a compressor, and a planetary gear train having an Auxiliary Power Unit (APU) mode in which the electric motor is in driving engagement with the compressor via the planetary gear train while the combustion engine is disengaged from the output shaft, and a propulsion mode in which the combustion engine and the electric motor are in driving engagement with the output shaft via the planetary gear train.

Abstract: A propulsion system for an aircraft having a nacelle and a fuselage is provided. The nacelle has a gas flow path and a nacelle interior region. The system includes a compressor section, an intermittent IC engine, a turbine section, a fan, and an IC cooling system. A first electric motor powers the compressor section. The compressor section produces a flow of elevated pressure compressor air. The intermittent IC engine selectively intakes the compressor air flow and produces an exhaust gas flow. The turbine section powered by exhaust gas in turn powers a first electric generator. The fan is driven by a second electric motor. The IC engine cooling system has a heat exchanger disposed within the gas flow path, coolant, coolant piping, and a pump. The heat exchanger is disposed in the nacelle.