Abstract: An oil filler assembly for an aircraft engine, has: a filler tube extending from a bottom end to a top end; a valve having a tube side fluidly connected to the filler tube and a tank side; a cap removably secured to the top end; a dipstick secured to the cap and extending into the filler tube; and a piston secured to the dipstick, the piston having: a sealing configuration in which the piston sealingly engages the filler tube to fluidly disconnect the top end from the valve, the piston being in the sealing configuration when the cap is secured to the top end of the filler tube; and a venting configuration in which the piston permits fluid communication between the top end and the valve, the piston being in the venting configuration when the cap is moved away from the top end of the filler tube.

Abstract: An oil filler assembly, has: a filler tube extending from a bottom end to a top end; a non-return valve having a tube side and a tank side; a cap assembly including a cap removably secured to the filler tube and a dipstick projecting from the cap; a vent having an inlet connected to the tank side and an outlet connected to the tube side, the vent defining a flow path bypassing the non-return valve; and a safety valve connected to the vent and having an open configuration in which fluid flow is permitted and a closed configuration in which fluid flow is prevented, the safety valve being engageable by the cap assembly to bias the safety valve in the open configuration when the cap is secured to the top end, the safety valve being in the closed configuration when the cap assembly is detached from the top end.

Abstract: The seal assembly can have a support ring having an annular shape defined around a seal axis, and a plurality of strips of a metal material, each strip of the plurality of strips being folded along a length of the strip forming a fold and a pair of segments extending radially inwardly from the fold, relative the seal axis, the fold secured at the support ring, the fold having a bending radius defined around a bending axis, the bending axis oriented parallel to the seal axis, the plurality of strips being arranged circumferentially relative one another, around the seal axis.

Abstract: Dual bypass gas turbine engines and associated methods are provides. A dual bypass turbofan gas turbine engine includes counter-rotating first and second fans through which ambient air is received and propelled in an aft direction; a first bypass duct receiving first bypass air including a first portion of the propelled air; a second bypass duct receiving second bypass air including a second portion of the propelled air; a core gas path receiving core air including a third portion of the propelled air; a compressor pressurizing the core air; an intercooler facilitating heat removal from the pressurized core air; a combustor in which the pressurized core air is mixed with fuel and ignited to generate a stream of combustion gas; a turbine extracting energy from the combustion gas; and a differential gear train apportioning an input torque received from the turbine between the first fan and the second fan.

Abstract: The coupling can have a female member having a plurality of female member connections circumferentially arranged along a radially inner face; a male member having a plurality of male member connections circumferentially arranged along a radially outer face; and a coupling member extending annularly around the axis, the coupling member having a strip, the strip having, circumferentially relative the axis, an alternating sequence of outer folds and inner folds, the outer folds connected to the female member via respective ones of the female member connections, the inner folds connected to the male member via respective ones of the male member connections, the inner folds being circumferentially offset from the outer folds in a given angular direction.

Abstract: A gas turbine engine includes a turbine for driving a shaft to in turn drive a rotor. A combustor receives compressed air, and combusts the compressed air. The shaft is supported by at least one bearing. An oil delivery system is associated with the at least one bearing including an oil scoop rotating with the at least one shaft and a stationary oil jet provided with a source of lubricant. A mixed fluid chamber is within the shaft. The mixed fluid chamber is connected to an air exit. There further is an oil chamber radially outward of the mixed fluid chamber. The oil chamber is connected to the at least one bearing.

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: An assembly for a gas turbine engine includes at least one burner and a hydrogen manifold. The at least one burner includes an outer nozzle and an inner nozzle. The outer nozzle forms a combustion chamber. The outer nozzle includes an outer converging axial portion and an outer diverging axial portion. The outer converging axial portion is disposed at an upstream axial end of the outer nozzle. The outer diverging axial portion is disposed axially downstream of the outer converging axial portion. The inner nozzle includes an inner converging axial portion at a downstream axial end of the inner nozzle. The inner converging axial portion is disposed within the outer converging axial portion to form an annular gap between the outer converging axial portion and the inner converging axial portion. The hydrogen manifold is disposed at the upstream axial end. The hydrogen manifold is connected in fluid communication with the annular gap.

Abstract: Systems and methods for cooling electric machines are provided. A method for cooling an electric machine includes receiving a flow of air, expanding and cooling the air from the flow of air using a turbine, conveying the flow of air from the turbine through the electric machine to extract heat from the electric machine using the flow of air, and drawing the flow of air through the electric machine using an air mover.

Abstract: An assembly is provided for a gas turbine engine. This assembly includes a rotating structure of the gas turbine engine, a stationary structure of the gas turbine engine and a volume formed by and extending between the rotating structure and the stationary structure. The rotating structure is rotatable about an axis. The rotating structure includes a seal land and a fluid nozzle. The stationary structure includes a seal element. The seal element is arranged with the seal land to form a seal assembly that seals an annular gap between the stationary structure and the rotating structure. The volume is adjacent the seal element and the seal land. The fluid nozzle is configured to direct a fluid jet out from the rotating structure and into the volume.

Abstract: A gas turbine engine includes a turbine for driving a shaft to in turn drive a rotor. A combustor receives compressed air, and combusts the compressed air. The shaft is supported by at least one bearing. An oil delivery system is associated with the at least one bearing including an oil scoop rotating with the at least one shaft and a stationary oil jet provided with a source of lubricant. A mixed fluid chamber is within the shaft. The mixed fluid chamber is connected to an air exit. There further is an oil chamber radially outward of the mixed fluid chamber. The oil chamber is connected to the at least one bearing.

Abstract: An accessory power unit assembly includes a combustor assembly that includes a pulse detonation tube that defines a curved passage between an inlet that receives a compressed airflow and a discharge end. The detonation tube operates as a resonant cavity to sustain a standing pressure wave. Fuel injected into the pulse detonation tube is timed to coincide with movement of a standing wave toward a discharge end. The standing wave provides an increase in pressure of an output exhaust gas driving the turbine without a corresponding increase in load.

Abstract: The coupling can have a female member having a plurality of female member connections circumferentially arranged along a radially inner face; a male member having a plurality of male member connections circumferentially arranged along a radially outer face; and a coupling member extending annularly around the axis, the coupling member having a strip, the strip having, circumferentially relative the axis, an alternating sequence of outer folds and inner folds, the outer folds connected to the female member via respective ones of the female member connections, the inner folds connected to the male member via respective ones of the male member connections, the inner folds being circumferentially offset from the outer folds in a given angular direction.

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: The seal assembly can have a support ring having an annular shape defined around a seal axis, and a plurality of strips of a metal material, each strip of the plurality of strips being folded along a length of the strip forming a fold and a pair of segments extending radially inwardly from the fold, relative the seal axis, the fold secured at the support ring, the fold having a bending radius defined around a bending axis, the bending axis oriented parallel to the seal axis, the plurality of strips being arranged circumferentially relative one another, around the seal axis.

Abstract: An aircraft engine, comprising: a shaft; a bearing housing extending around the shaft and defining a bearing cavity; a bearing in the bearing cavity and rotatably supporting the shaft; a squeeze film damper including: a first seal proximate a first end of the bearing, and a second seal proximate a second end of the bearing; an annulus between the first seal and the second seal, the annulus having a damping fluid in the annulus; and wherein at least the first seal includes a sealing ring received within a groove extending axially from an outer groove wall to an inner groove wall, the inner groove wall located axially between the outer groove wall and the annulus, the sealing ring having an outer ring face facing the outer groove wall and an inner ring face facing the inner groove wall, the inner ring face being movable relative to the outer ring face.

Abstract: An aircraft engine is described which has: a shaft; a bearing housing extending around the shaft and defining a bearing cavity; a bearing within the bearing cavity and supporting the shaft; a squeeze film damper having an annulus receiving a damping fluid; and a controller. The controller is configured to: operate the squeeze film damper in a first regime in which a speed of the damping fluid in the annulus is less than a speed of sound in the damping fluid; determine that the shaft is subjected to vibrations having an amplitude greater than an amplitude threshold; and upon determining that the amplitude of the vibrations is greater than the amplitude threshold, operate the squeeze film damper in a second regime in which the speed of the damping fluid in the annulus is greater than the speed of sound in the damping fluid.

Abstract: The heat exchanger can include one or more Helmholtz resonator having a cavity internal to the skin of the vehicle, the cavity delimited by a wall, the Helmholtz resonator having an aperture formed across the skin and fluidly connecting the cavity to the atmosphere, the cavity extending in the forward orientation of motion relative the aperture, an open cell structure filling at least a portion of the cavity; and a fluid passage internal to the skin, the fluid passage in thermal communication with the cavity via the wall of the cavity.

Abstract: The coupling can have a female member having a plurality of female member connections circumferentially arranged along a radially inner face; a male member having a plurality of male member connections circumferentially arranged along a radially outer face; and a coupling member extending annularly around the axis, the coupling member having a strip, the strip having, circumferentially relative the axis, an alternating sequence of outer folds and inner folds, the outer folds connected to the female member via respective ones of the female member connections, the inner folds connected to the male member via respective ones of the male member connections, the inner folds being circumferentially offset from the outer folds in a given angular direction.

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.