Abstract: A hybrid powerplant is provided for an aircraft. This hybrid powerplant includes a housing, an electric machine, a machine fluid circuit, a heat engine and a geartrain. The housing includes a machine containment zone and an engine compartment outside of the machine containment zone. The electric machine is arranged within the machine containment zone. The machine fluid circuit services the electric machine. The machine fluid circuit extends in the machine containment zone and is arranged outside of the engine compartment. The heat engine is arranged within the engine compartment. The geartrain is operatively connected to the electric machine and the heat engine.

Abstract: A housing assembly for a rotary engine, has: a rotor housing having a peripheral inner face, a first face and a second face; a first side defining a first inner side face; and a second side housing defining a second inner side face, the rotor cavity bounded between the first side housing and the second side housing, one or more of the rotor housing, the first side housing, and the second side housing having: a main body made of a base material; and an external layer made of an external material, the base material and the external material being dissimilar to one another, a wear-resistance of the external material greater than that of the base material, the external layer defining at least a part of one or more of the first face, the second face, the peripheral inner face, the first inner side face, and the second inner side face.

Abstract: A hydrogen supply assembly for an aircraft propulsion system includes a storage housing, a hydrogen supply component, and a leak detection system. The storage housing surrounds and forms a storage plenum. The hydrogen supply component is disposed within the storage housing coincident with the storage plenum. The leak detection system includes an interior pressure sensor, an exterior pressure sensor, and a controller. The interior pressure sensor is connected in fluid communication with the storage plenum. The exterior pressure sensor is connected in fluid communication with an ambient atmosphere outside the storage housing.

Abstract: A fuel injector for a gas turbine engine combustor is provided that includes a swirler, a mounting stage, and a distributor. The swirler has a shaft, a collar, a throat section, and first and second axial ends. The throat section includes an inner radial surface that defines a central passage that extends between the swirler inner bore and the collar. The collar includes a plurality of apertures extending therethrough disposed radially outside of the central passage. The mounting stage is disposed in the inner bore, and has an annular flange, a central hub, and at least one strut. The distributor has a stem attached to a head. The stem has a distal end opposite the head portion engaged with the central hub. The head portion has an end surface and a side surface. The distributor is selectively positionable relative to the throat section.

Abstract: A vane outer shroud for a gas turbine engine is disclosed. The vane outer shroud includes a vane coupled to the vane outer shroud, an area downstream of the vane through which a rotor blade rotates about an axis relative to the vane, and a groove formed in the vane outer shroud upstream and adjacent to a leading edge of the rotor blade. The groove is configured to recirculate air and/or gas radially inward toward the rotor blade.

Abstract: A rotor of an aircraft engine has a plurality of blades extending radially from a disc. At least one of the blades has an airfoil, a root and a tip. The airfoil has a crack-mitigating rib extending chordwise along the airfoil. The crack-mitigating rib is disposed radially closer to the root than to the tip.

Abstract: A rotor assembly for an aircraft engine that includes a compressor rotor and a turbine rotor mounted to a shaft for rotation about a central axis, and a gyroscopic stiffener also mounted to shaft. The gyroscopic stiffener includes a gyroscopic disk extending radially away from the shaft and located at an axial position that is spaced apart from the bearings, and an attachment mechanism connecting the gyroscopic disk to the rotor assembly. The attachment mechanism allows the gyroscopic disk to move in one of two degrees of freedom relative to the shaft, the two degrees of freedom including a rotational degree of freedom wherein the gyroscopic disk is rotatable at a greater rotational speed that a remainder of the rotor assembly, and an angular degree of freedom wherein the gyroscopic disk is orientated at a precession deflection angle relative to the plane and/or the central axis.

Abstract: A fuel injector includes a first fuel path, a second fuel path, and an air path. The first fuel path is independent from the second fuel path. The ratio of a first outlet area of the first fuel path, a second outlet area of the second fuel path, and a third outlet area of the air path is constant. A fuel system includes a first fuel source, a second fuel source, an air source, and the injection. The first fuel source is fluidly connected to the first fuel path. The second fuel source is fluidly connected to the second fuel path. The air source is fluidly connected to the air path.

Abstract: An air duct interface for an aircraft engine is disclosed herein. The air duct interface includes a first air duct, a first outer wall, a mating interface disposed circumferentially around the first outer wall, a second air duct, a second outer wall, and a gasket interface disposed circumferentially around the second outer wall. The mating interface includes a first angled portion extending away from the first outer wall in a first direction and a second angled portion extending away from the first outer wall in a second direction opposite the first direction. The gasket interface includes a first portion extending away from the second outer wall in the first direction, wherein the first portion is configured to engage the first angled portion and a second portion extending away from the second outer wall in the second direction, wherein the second portion is configured to engage the second angled portion.

Abstract: A method of machining a feature in a component using a machine having a support rotatable about a rotation axis and having a cutting tool movable relative to the component, the component being mounted on the support for rotation about a central axis of the component, the method includes: determining coordinates of at least three points on a reference surface of the component, the at least three points being circumferentially offset from one another relative to the central axis; determining an angular correction to apply to the cutting tool based on the coordinates of the at least three points; and machining the feature in the component using the cutting tool angled with the angular correction.

Abstract: A power supply arrangement (PSA) for an aircraft having an electrical system and an environmental control system (ECS) operatively connected to a cabin of the aircraft, the PSA has: at least one propelling engine; a secondary power unit (SPU) having a rotary engine, at least one generator in driving engagement with the rotary engine and operatively connectable to the electrical system of the aircraft, and at least one load compressor operatively connected to the rotary engine and pneumatically connected to a pneumatic circuit connectable to the ECS of the aircraft, the PSA having a propelling configuration in which the at least one propelling engine and the SPU are both powered and a hotel configuration in which the at least one propelling engine is unpowered while the SPU is powered, the pneumatic circuit pneumatically disconnected from the at least one propelling engine in both of the hotel and propelling configurations.

Abstract: Aircraft engine oil tanks, lubrication systems, and associated methods are provided. The oil tank includes a first tank portion defining a first volume for holding oil and a second tank portion defining a second volume for holding oil, in fluid communication with the first volume. The first tank portion includes an oil outlet for delivering oil to a lubrication load via a pump. The first volume is in fluid communication with a vent opening for venting the oil tank. At least part of the second tank portion is disposed higher than the vent opening for retaining a quantity of oil inside the oil tank during a negative-g force flight condition and facilitate the recovery of the lubrication system following the negative-g force flight condition.

Abstract: A gas turbine engine includes a casing including a plurality of interconnected casing segments defining an outer surface of the casing. One of the casing segments is a gearbox segment enclosing a gearbox and having a gearbox flange extending radially outwardly from the outer surface of the casing. The engine includes a bearing housing enclosing at least one bearing and having an annular body with an inner segment disposed within the casing. The annular body having an extension segment extending radially outwardly from the inner segment to a bearing housing flange disposed radially-outwardly of the outer surface of the casing. The bearing housing flange is engageable with the gearbox flange to removably mount the gearbox segment to the bearing housing.

Abstract: A logic circuit includes a timer and a plurality of switch assemblies in signal communication with the timer. Each switch assembly of the plurality of switch assemblies includes a switch including a true input gate, a false input gate, and an output gate, a first delay in signal communication with the output gate, and a second delay in signal communication between the output gate and the false input gate.

Abstract: A hybrid-electric propulsion (HEP) system is provided that includes a gas turbine engine, an electrical power motive system, a system controller, and a propulsor. The gas turbine engine has a free turbine configuration and a compressor. The electrical power motive system has first and second electric motors and first and second inverters. The gas turbine engine provides motive force to the propulsor. The first electric motor is configurable in a drive mode or in generator mode. The second electric motor is in communication with the compressor. The system controller is in communication with the gas turbine engine, the first and second inverters, and a non-transitory memory storing instructions, which instructions cause the system controller to control the second inverter to operate the second electric motor to provide a motive force to the compressor of the gas turbine engine during a low power setting of the gas turbine engine.

Abstract: A containment assembly is provided for an aircraft engine having a rotor with a set of blades. The containment assembly comprises a containment casing annularly surrounding the rotor radially outward of the set of blades. The containment casing is made of a material having a density less than that of steel. A layer of thermal insulation is disposed radially inward of the containment casing. The layer of thermal insulation is radially disposed between the containment casing and the set of blades.

Abstract: An engine carcass stiffener for a turboprop engine is provided. The engine carcass stiffener includes a first longitudinal reinforcement member, a proximal end of the first longitudinal reinforcement member is coupled to a first end of a proximal flange; a second longitudinal reinforcement member, a proximal end of the second longitudinal reinforcement member is coupled to a second end of the proximal flange; a first bushing holder, the first bushing holder is coupled to a first end of a distal flange; a second bushing holder, the second bushing holder is coupled to a second end of the distal flange; a first bolt, the first bolt is inserted through the first bushing holder and couples to a distal end of the first longitudinal reinforcement member; and a second bolt, the second bolt is inserted through the second bushing holder and couples to a distal end of the second longitudinal reinforcement member.

Abstract: A gas turbine engine includes a compressor section and a turbine section. A heat exchanger is operable to cool a fluid utilized by a component of the gas turbine engine. The heat exchanger has an inlet and an outlet for the accessory fluid. A strain gauge is associated with the fluid inlet and operable to produce a signal indicative of a temperature of the fluid at the fluid inlet and a strain gauge is associated with the fluid outlet and operable to produce a signal indicative of a temperature of the fluid at the fluid outlet. A controller determines a temperature differential across the heat exchanger by utilizing the signal from the strain gauge at the fluid inlet and the signal from the strain gauge at the fluid outlet. A method and a heat exchanger are also disclosed.

Abstract: A test rotor blade for an aircraft engine bladed rotor includes a blade body. The blade body extends between and to a leading edge and a trailing edge. The blade body forms a first side surface and a second side surface. The blade body forms a leading-edge pocket at the leading edge, a trailing-edge pocket at the trailing edge, and a hole extending through the blade body from the leading-edge pocket to the trailing edge pocket. The blade body includes a first side wall and a second side wall. The first side wall has a first wall thickness extending between and to the first side surface and the hole. The second side wall has a second wall thickness extending between and to the second side surface and the hole. The second wall thickness is 0.4 to 0.9 times the first wall thickness.

Abstract: Hybrid aircraft power plants are provided together with associated systems and methods for operating such hybrid aircraft power plants. A hybrid aircraft power plant includes a thermal engine, an electric motor and one or more controllers operatively connected to the thermal engine and to the electric motor. The thermal engine and the electric motor are drivingly connected to an air mover of an aircraft via a combining gear train. The one or more controllers are configured to govern an actual output torque of the electric motor to reduce an error between a target operating speed for the air mover and an actual operating speed of the air mover, and govern an output of the thermal engine to reduce an error between a target output torque for the electric motor and the actual output torque of the electric motor.