Abstract: A system for forming a nozzle inlet of a nozzle includes a nozzle body and an electro-chemical machining (ECM) assembly. The nozzle body includes an external surface. The nozzle body forms a nozzle orifice and a manifold passage. The nozzle orifice extends through the nozzle body between and to a nozzle inlet and a nozzle outlet. The nozzle inlet is disposed at the manifold passage. The nozzle outlet is disposed at the external surface. The ECM assembly is installed on the nozzle body. The ECM assembly includes a machining tool and a flexible line. The machining tool is disposed at the nozzle inlet. The flexible line is attached to the machining tool. The flexible line extends through the nozzle outlet from the machining tool to an exterior of the nozzle body.

Abstract: A fluid cooler for installation in a bypass duct of a turbofan gas turbine engine and associated methods are provided. The fluid cooler includes an inlet duct, a heat exchanger and an outlet duct. The inlet duct includes an inlet protruding into the bypass duct to receive a portion of the bypass air into the inlet duct. The heat exchanger is in fluid communication with the inlet duct. The heat exchanger facilitates heat transfer between a fluid and the portion of bypass air received into the inlet duct. The heat exchanger defines a general flow direction for the portion of bypass air that is different from the main flow direction of bypass air inside the bypass duct. The outlet duct conveys the portion of bypass air from the heat exchanger back to the bypass duct.

Abstract: A vapor-to-air heat exchanger for an aircraft powerplant that includes: a pressurized vapor source supplying vapor; and a condenser including a condenser inlet in fluid communication with the pressurized vapor source to receive the vapor, a condenser outlet, and at least one pneumatic vessel defining a cavity in fluid communication between the condenser inlet and the condenser outlet. The pneumatic vessel is reversibly inflatable to be configurable between a collapsed vessel configuration and an inflated vessel configuration. A volume of the cavity is greater in the inflated vessel configuration than in the collapsed vessel configuration. The pneumatic vessel is inflatable from the collapsed vessel configuration to the inflated vessel configuration when the cavity is pressurized by the vapor.

Abstract: An oil tank for a gas turbine engine is provided. The oil tank includes an oil cavity defined within structural walls of a nacelle of the gas turbine engine, the oil cavity having an oil inlet and an oil outlet. At least one of the structural walls has an interior side facing the oil cavity and an exterior side. The interior side includes a plurality of upstanding protrusions extending into the oil cavity and fully immersed in oil when the gas turbine engine is in use during steady state operation. The exterior side includes a plurality of fins extending therefrom and exposed to an ambient air stream during steady state operation of the gas turbine engine.

Abstract: A fluid supply system and method is provided that includes a fluid pump, a pressure sensor, a pressure relief valve (PRV), and a fluid monitoring device. The fluid pump receives fluid from a first conduit and discharges fluid into a second conduit. The pressure sensor produces sensed fluid pressure signals. The PRV is in signal communication with the pressure sensor. The fluid monitoring device includes a control orifice in fluid communication with second and third conduits. The second conduit has a first inner diameter, the third conduit has a second inner diameter, and the control orifice has an orifice inner diameter, and the orifice inner diameter is less than the first and second inner diameters. The pressure sensor senses fluid pressure in the third conduit at a position in close proximity to the control orifice. The fluid monitoring device may be in a lead or a lag domain configuration.

Abstract: Electric aircraft power plants and associated methods are provided. One power plant includes an emergency power unit (EPU) for providing electric power in the event of a malfunction of a battery pack of an electric aircraft to permit the electric aircraft to make an emergency maneuver. The EPU includes a rocket engine for generating a stream of exhaust fluid using a rocket propellant, a turbine operatively connected to extract energy from the stream of exhaust fluid generated by the rocket engine, and an electric generator operatively connected to be driven by the turbine and to supply electric power to an electric motor propelling the electric aircraft.

Abstract: An aircraft assist system described herein includes an aircraft coupling counterpart attached to a strut of a landing gear of an aircraft, and an assist vehicle. The assist vehicle includes a frame, ground-engaging wheels mounted to the frame, a power source for driving one or more of the ground-engaging wheels, and a vehicle coupling counterpart for engagement with the aircraft coupling counterpart. The aircraft coupling counterpart and the vehicle coupling counterpart define a swivel connection for transferring a propulsive force from the takeoff assist vehicle to the aircraft. The aircraft coupling counterpart is disengageable from the vehicle coupling counterpart by upward movement of the aircraft coupling counterpart relative to the vehicle coupling counterpart.

Abstract: Blowdown valves and associated methods for separating oil and air in a lubrication system of an aircraft engine are provided. A method includes receiving a mixture of air and oil at a blowdown valve including a valve member movable between a valve-closed position and a valve-open position. With the valve member in the valve-open position, the method includes impinging the mixture against the valve member. A first portion of the mixture having a first fraction of oil is released from the blowdown valve upstream of the valve member. A second portion of the mixture having a second fraction of oil greater than the first fraction of oil is guided around and past the valve member. The second portion of the mixture is released from the blowdown valve downstream of the valve member.

Abstract: Electric aircraft power plants and associated methods are provided. One power plant includes an emergency power unit (EPU) for providing electric power in the event of a malfunction of a battery pack of an electric aircraft to permit the electric aircraft to make an emergency maneuver. The EPU includes a rocket engine for generating a stream of exhaust fluid using a rocket propellant, a turbine operatively connected to extract energy from the stream of exhaust fluid generated by the rocket engine, and an electric generator operatively connected to be driven by the turbine and to supply electric power to an electric motor propelling the electric aircraft.

Abstract: Lubrication systems of an aircraft engine and associated methods are provided. The lubrication system includes a chamber having a fluid inlet for receiving lubricating fluid into the chamber, and a fluid outlet for draining the lubricating fluid from the chamber. The fluid outlet is disposed on a wall defining part of the chamber. A rotor is disposed inside the chamber and interacts with the lubricating fluid inside the chamber. The rotor is rotatable in a rotation direction about a rotation axis. A perforated baffle is disposed in the chamber for interacting with the lubricating fluid inside the chamber. The perforated baffle includes a base attached to the wall of the chamber. The base of the perforated baffle is disposed at an angular position preceding the fluid outlet relative to the rotation direction of the rotor.

Abstract: A system is provided for an aircraft. This aircraft system includes a propulsor, a powerplant and a control system. The powerplant is configured to output mechanical power to drive rotation of the propulsor. The powerplant includes a heat engine and an electric machine. The heat engine is configured to provide a first portion of the mechanical power. The electric machine is configured to provide a second portion of the mechanical power. The control system is configured to operate the powerplant to control a rotational speed of the propulsor by adjusting the second portion of the mechanical power.

Abstract: An aircraft assist system described herein includes an aircraft coupling counterpart attached to a strut of a landing gear of an aircraft, and an assist vehicle. The assist vehicle includes a frame, ground-engaging wheels mounted to the frame, a power source for driving one or more of the ground-engaging wheels, and a vehicle coupling counterpart for engagement with the aircraft coupling counterpart. The aircraft coupling counterpart and the vehicle coupling counterpart define a swivel connection for transferring a propulsive force from the takeoff assist vehicle to the aircraft. The aircraft coupling counterpart is disengageable from the vehicle coupling counterpart by upward movement of the aircraft coupling counterpart relative to the vehicle coupling counterpart.

Abstract: Systems and methods for delivering a buffer fluid to a shaft seal of a gas turbine engine are provided. An exemplary system includes, a buffer fluid source, one or more first conduits providing fluid communication between the buffer fluid source and the shaft seal along a first route, and one or more second conduits providing fluid communication between the buffer fluid source and the shaft seal along a second route different from the first route. A heat exchanger is also disposed along the first route to facilitate heat transfer between buffer fluid in the one or more first conduits and a cooling fluid.

Abstract: An aircraft engine comprises a casing extending circumferentially around a central axis. A support flange is secured to the casing and extends circumferentially around the axis. The support flange has an inner and an outer flange face. A component is drivingly engaged by a shaft of the engine. The component has a connecting section extending around the central axis. The connecting section has a connecting face. The inner flange face is in abutment against the connecting face. A retaining ring extends circumferentially around the central axis. The retaining ring is in abutment against the outer flange face of the support flange. The retaining ring has a coefficient of thermal expansion, which is less than that of the support flange.

Abstract: A vapor-to-air heat exchanger for an aircraft powerplant that includes: a pressurized vapor source supplying vapor; and a condenser including a condenser inlet in fluid communication with the pressurized vapor source to receive the vapor, a condenser outlet, and at least one pneumatic vessel defining a cavity in fluid communication between the condenser inlet and the condenser outlet. The pneumatic vessel is reversibly inflatable to be configurable between a collapsed vessel configuration and an inflated vessel configuration. A volume of the cavity is greater in the inflated vessel configuration than in the collapsed vessel configuration. The pneumatic vessel is inflatable from the collapsed vessel configuration to the inflated vessel configuration when the cavity is pressurized by the vapor.

Abstract: A heating system for heating a component in a liquid distribution system of an aircraft engine. The liquid distribution system feeds a liquid to the component. The heating system includes an acoustic generator disposed in communication with the component via a liquid passage of the liquid distribution system. The liquid passage defines a length between the acoustic generator and the component. The acoustic generator generates a resonant frequency selected as a function of the length of the liquid passage to generate a standing wave in the liquid within the liquid passage. The standing wave transmitting energy to the component to heat the component.

Abstract: A machine includes a liquid lubrication system and a shaft, the shaft being rotatable about a rotation axis, the shaft including a first part, a second part engaged coaxially with the first part, and a journal bearing between the first part and the second part, the first part being rotatable relative to the second part about the rotation axis, a helical feature disposed between the first part and the second part and configured to define a helical pump between the first part and the second part, the pump being hydraulically connected to the liquid lubrication system, the journal bearing being disposed adjacent to the helical feature.

Abstract: An oil supply system for supplying oil to a lubricating cavity of a gas turbine engine, the oil supply system has: a de-oiler having a de-oiler air-oil inlet, a de-oiler oil outlet hydraulically connected to the lubricating cavity, and a de-oiler air outlet in fluid flow communication with an environment outside of the oil supply system; and a closed-loop oil circuit including a main pump having a main pump inlet and a main pump outlet, the main pump outlet hydraulically connected to the lubricating cavity, a de-aerator having a de-aerator inlet hydraulically connected to a scavenge outlet of the lubricating cavity, a de-aerator air-oil outlet in fluid flow communication with the de-oiler inlet, and a de-aerator oil outlet hydraulically connected to the main pump inlet.

Abstract: A gas turbine engine includes a fan assembly, a compressor assembly, a combustion chamber, a turbine assembly, a bypass duct conveying rearward a bypass airstream driven by the fan assembly when the gas turbine engine is in use, a fairing extending across at least a portion of the bypass duct downstream of the fan assembly, and a heat exchanger having an inlet fluidly connected to the compressor assembly and an outlet fluidly connected to a pneumatic actuator of the gas turbine engine. The fairing has a leading edge and a trailing edge. The heat exchanger is disposed adjacent the trailing edge of the fairing.

Abstract: An aircraft engine comprises a casing extending circumferentially around a central axis. A support flange is secured to the casing and extends circumferentially around the axis. The support flange has an inner and an outer flange face. A component is drivingly engaged by a shaft of the engine. The component has a connecting section extending around the central axis. The connecting section has a connecting face. The inner flange face is in abutment against the connecting face. A retaining ring extends circumferentially around the central axis. The retaining ring is in abutment against the outer flange face of the support flange. The retaining ring has a coefficient of thermal expansion, which is less than that of the support flange.