Abstract: The gas turbine engine can have an engine core; a core output shaft drivable by the engine core; a power output shaft; an auxiliary power shaft; and a reduction gearbox having gears, the gears drivingly connecting the core output shaft to the auxiliary power shaft. The gears can include an epicyclic gearing drivingly connecting the core output shaft and the auxiliary power shaft to the power output shaft. The gas turbine engine can further have a second auxiliary power shaft interconnected to the auxiliary power shaft, the power output shaft, and the core output shaft by the gears.

Abstract: A system and method for detecting fixed pitch operation of a variable pitch propeller of an engine are provided. A command signal for maintaining a rotational speed of the propeller at a reference speed is output. An actual value of at least one of the rotational speed and a blade angle of the propeller is obtained. From the actual value, it is assessed whether an expected change in the at least one of the rotational speed and the blade angle of the propeller has occurred in response to the command signal. Responsive to determining that the expected change in the at least one of the rotational speed and the blade angle of the propeller has not occurred in response to the command signal, operation of the propeller at fixed pitch is detected and an alert output accordingly.

Abstract: A tool and an associated process for removing a press-fit component from an associated engine component, wherein the engine component is pushed in a first axial direction while the press-fit component is restrained from axially moving in the first axial direction.

Abstract: In an asymmetric operating regime, a first engine is operating in an active mode to provide motive power to an aircraft while a second engine is operating in a standby mode and de-clutched from a gearbox of the aircraft. In response to an emergency exit request, the second engine's speed is increased, at a maximum permissible rate, to a re-clutching speed while increasing the first engine's power output at a maximum permissible rate. When the re-clutching speed is reached, the second engine's power output is increased at a maximum permissible rate. In response to a normal exit request, the second engine's speed is increased to the re-clutching speed at a rate lower than the maximum permissible rate. When the re-clutching speed is reached, the second engine's power output is increased at a rate lower than the maximum permissible rate.

Abstract: A deaeration system for an engine lubrication system, the deaeration system comprising: a deaeration rotor rotatable about an axis and including: a rotor inlet extending circumferentially around the axis, a first and a second rotor outlet, a first rotor passage in fluid communication between the rotor inlet and the first rotor outlet, and a second rotor passage in fluid communication between the rotor inlet and the second rotor outlet in parallel to the first rotor passage; and a deaeration conduit including: a conduit inlet, a splitter downstream of the conduit inlet relative to a flow of lubricant through the deaeration conduit, a first conduit outlet and a second conduit outlet downstream of the splitter, the first conduit outlet in fluid communication with the rotor inlet, the conduit inlet having a curved portion extending away from the splitter.

Abstract: An assembly includes a rotor housing, a first rotor, a lubrication system, a first vibration sensor, and an engine control system. The rotor housing forms a first rotor cavity. The first rotor is configured for rotation within the first rotor cavity. The first rotor includes the plurality of apex seals. The lubrication system is configured to supply a lubrication flow for lubrication of the plurality of apex seals. The first vibration sensor is on the rotor housing. The first vibration sensor is configured to generate a vibration measurement signal. The engine control system includes a processor in communication with a non-transitory memory storing instructions, which instructions when executed by the processor, cause the processor to: identify that the vibration measurement signal exceeds a first vibration threshold, and increase a flow rate of the lubrication flow based on an identification of the vibration measurement signal exceeding the first vibration threshold.

Abstract: A turbine blade for a gas turbine engine has an airfoil including leading and trailing edges joined by spaced-apart pressure and suction sides to provide an external airfoil surface extending from a platform in a spanwise direction to a tip. The external airfoil surface is formed in substantial conformance with multiple cross-sectional profiles of the airfoil defined by a set of Cartesian coordinates set forth in Table 1, the Cartesian coordinates provided by an axial coordinate scaled by a local axial chord, a circumferential coordinate scaled by a local axial chord, and a span location.

Abstract: A combustor includes a liner defining a combustion chamber, and receiving an air and fuel mixing body. The mixing body includes a forward face facing into the combustion chamber. A plurality of circumferentially spaced columns about a central axis of the combustor each have at least two fuel supply passages and two air supply passages extending to the forward face. At least one of the two air supply passages and one of the fuel supply passages extending along a direction with a circumferentially extending component in a first circumferential direction. The other of the two air supply passages and the fuel supply passages extend with a circumferential component in a second opposed circumferential direction. A gas turbine engine is also disclosed.

Abstract: A combustor for a gas turbine engine includes a liner surrounding a fuel and air mixing body. A gaseous fuel supply passage delivers gaseous fuel into the mixing body. A wall of the mixing body has air openings to communicate air into mixing passages. At least one fuel opening in each of the mixing passages allows fuel to flow into the mixing passages and mix with the air. There are passage sections downstream of a location of the fuel openings, such that the mixed air and fuel travel downstream of the location and into a combustion chamber. The passage sections have baffles that create a tortuous path. A gas turbine engine is also disclosed.

Abstract: A fuel manifold adapter for a fuel system of an aircraft engine, the fuel manifold adapter comprising: a body having a body-output interface defining a downstream end of a body passage including a body bore about a bore axis, the body-output interface movably and fluidly connectable to a first component of the fuel system mounted to a first mounting point of the engine, and a body-input interface defining an upstream end of the body passage, the body-input interface rigidly and fluidly connectable to a second component of the fuel system mounted to a second mounting point of the engine, and a transfer tube having an upstream-tube end slidably engaged with the body along the bore axis via the body bore, the transfer tube having a downstream-tube end opposite the upstream-tube end slidably engageable along the bore axis with the first component, the downstream-tube end defining a downstream end of the fuel manifold adapter relative to fuel flow through the fuel manifold adapter.

Abstract: Aircraft power plants and associated methods are provided. A method for driving a load on an aircraft includes: transferring motive power from an internal combustion (IC) engine to the load; discharging a flow of first exhaust gas from the IC engine when transferring motive power from the IC engine to the load; receiving the flow of first exhaust gas from the IC engine into a combustor; mixing fuel with the first exhaust gas in the combustor and igniting the fuel to generate a flow of second exhaust gas; receiving the flow of second exhaust gas at a turbine and driving the turbine with the flow of second exhaust gas from the combustor; and transferring motive power from the turbine to the load.

Abstract: 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.

Abstract: A coupling nut for sealingly engaging a ferrule of a fluid line to a component of a hydraulic system, has: a shank extending along a central axis and having threads to engage a nipple, the threads extending circumferentially around the central axis, the shank defining an inner passage extending along the central axis and sized to receive the fluid line; and a head extending from the shank circumferentially around the inner passage relative to the central axis, the head: defining faces circumferentially distributed about the central axis and edges at junctions between the faces, the faces including torque-transmitting faces each facing a direction having a circumferential component relative to the central axis, and having a cross-section in a plane normal to the central axis, the cross-section defining a plurality of symmetry planes containing the central axis, the torque-transmitting faces free of intersection with the plurality of symmetry planes.

Abstract: A method of determining an inlet total air pressure includes determining a first parameter indicative of a first inlet total air pressure. The method includes executing a sequence that includes: determining a mass air flow passing through the air inlet based on the first parameter, determining a Mach number of air passing through the air inlet based on the mass air flow, determining a static air pressure at the air inlet, determining an air pressure ratio based on the Mach number, generating a subsequent parameter indicative of the revised inlet total air pressure based on the air pressure ratio and the static air pressure, and substituting the subsequent parameter for the first parameter. The method includes executing at least one additional instance of the sequence with the subsequent parameter, and outputting the subsequent parameter as the inlet total air pressure.

Abstract: A probe shielding arrangement comprises a sleeve having a radially inner end mounted to a turbine housing and a radially outer end floatingly received in a probe boss on an exhaust case. The sleeve circumscribes an annular cavity around the probe. The annular cavity is sealed at opposed ends thereof to form a dead air cavity around the probe for insulation purposes.

Abstract: A method of operating an engine of an aircraft, the engine having a bleed air system. The method includes in flight, directing pressurized air from a source of pressurized air external to the engine to the bleed air system of the engine. An aircraft, comprising a first engine having a bleed air system, a second engine having a bleed air system, and a source of pressurized air that is external to the first and/or the second engine, the source of pressurized air being selectively fluidly connectable to the bleed air system of the first and/or the second engine, is also disclosed.

Abstract: A structure is provided for a gas turbine engine. This gas turbine engine structure includes an engine case, an engine pylon and an engine line. The engine case includes a base, a mounting boss and a first support element. The base extends axially along and circumferentially about an axial centerline of the engine case. The mounting boss projects radially out from the base. The first support element projects radially out from the base and laterally out from the mounting boss. The first support element is configured as or otherwise includes a peripheral boss. The engine pylon is mounted to the mounting boss. The engine line is coupled to the peripheral boss.

Abstract: A diffuser pipe has a tubular body defining a pipe center axis extending therethrough. The tubular body includes a first portion extending in a generally radial direction from an inlet of the tubular body, a second portion extending in a generally axial direction and terminating at a pipe outlet, and a bend portion fluidly linking the first portion and the second portion. The tubular body has a length defined between the inlet and the pipe outlet. The tubular body has cross-sectional profiles defined in a plane normal to the pipe center axis. An area of the cross-sectional profile at the pipe outlet is at least 20% greater than an area of the cross-sectional profile at a point upstream from the pipe outlet a distance corresponding to 10% of the length of the tubular body.

Abstract: A multi-engine aircraft includes first and second gas turbine engines for providing motive power to the aircraft, each of the first and second engines comprising an air system, an air pressure line extending between and fluidly connecting the air systems of the first and second engines, and a pressure wave damper communicating with the air pressure line extending between the first and second engines.

Abstract: An electric machine system described herein comprises a first electric machine rotor, a first gear and a second gear. The first gear is connected to the first electric machine rotor and to a first input/output shaft. The second gear is connected to the first electric machine rotor and to a second input/output shaft. The first electric machine rotor is disposed between the first gear and the second gear.