A variable area fan nozzle (VAFN) actuation system is disclosed. The VAFN actuation system is part of an aircraft nacelle, comprising a thrust reverser translating sleeve and a VAFN cowl. The system may translate the VAFN cowl to various positions to optimize engine performance. The system works in two phases. The first phase occurs when the translating sleeve is stowed. During this time, a linear, fluid-pressure VAFN actuator with multiple pistons may translate the VAFN cowl forward and aftward, and hold it in various fixed positions. The second phase occurs when the translating sleeve deploys and then stows. During this time, the actuator may allow the VAFN cowl to travel with the translating sleeve in a controlled manner. When the translating sleeve deploys, the VAFN cowl is pushed aftward by the translating sleeve. When the translating sleeve stows, the VAFN cowl is pulled forward with it.

A nacelle for an aircraft bypass turbomachine, including: an annular envelope extending about a longitudinal axis, a thrust reverser including: an annular movable cowl situated downstream of the annular envelope and able to slide with respect to the annular envelope along the longitudinal axis between a closed position and an open position in which the cowl and the nacelle casing define an opening between one another, at least one first thrust reverser cascade, an actuating mechanism designed to allow a partial or total thrust-cancelling configuration of the thrust reverser, in which configuration the movable cowl is moved into its open position while maintaining the or each first cascade in its retracted position, the opening being occupied by at least one second thrust-attenuating cascade of the thrust reverser, in such a way that the secondary flow passing through the opening exits to the outside of the nacelle with a speed oriented so as to generate a substantially zero or positive thrust along the longitudinal axis.

The subject matter of this specification can be embodied in, among other things, a thrust reverser synchronization shaft lock system includes a rotatable shaft comprising at least one radial prong extending radially from the shaft, a hydraulic lock assembly that includes a housing, a piston head having a lock recess, a piston rod extending radially away from the shaft and configured to be urged by the piston head to move the first piston rod end out of engagement with the radial prong to selectably permit rotation of the shaft, and a bias member configured to urge the first piston rod end into engagement with the radial prong, and an electric lock assembly that includes a lock pin and an electric actuator configured to controllably extend and retract the lock pin in and out of engagement with the lock recess.

A closing system that includes a closing actuator for doors of a thrust reverser, two sliding members, and a detection device. The closing actuator includes two first connecting rods. Each first connecting rod is configured to be connected to a first lateral edge of each door. The closing actuator is arranged to move each door at least towards the direct jet position. Each sliding member carries a second connecting rod configured to be connected to a second lateral edge of each door. The second connecting rods are arranged to be driven by the doors when the closing actuator moves the doors towards the direct jet position so as to displace the two sliding members. The detection device detects a defect of one of the first and second connecting rods. The detection device is configured to detect the relative position of the two sliding members in the direct jet position.

A closing system that includes a closing actuator for doors of a thrust reverser, two sliding members, and a detection device. The closing actuator includes two first connecting rods. Each first connecting rod is configured to be connected to a first lateral edge of each door. The closing actuator is arranged to move each door at least towards the direct jet position. Each sliding member carries a second connecting rod configured to be connected to a second lateral edge of each door. The second connecting rods are arranged to be driven by the doors when the closing actuator moves the doors towards the direct jet position so as to displace the two sliding members. The detection device detects a defect of one of the first and second connecting rods. The detection device is configured to detect the relative position of the two sliding members in the direct jet position.

A propulsion system includes a bypass turbine engine and a pylon. The turbine engine includes an engine, two internal cowls, two outer cowls, a first lock for locking the internal cowls to the engine, cascades of vanes fixed to the outer cowl via hooping, wherein the outer cowls are movable in translation with respect to the engine, in which each outer cowl is able to slide parallel to a direction of translation on an internal cowl via a top guideway connection and a bottom guideway connection, and in which each outer cowl is mounted with the ability to slide parallel to the direction of translation on the pylon via an upper guideway connection. The propulsion system makes it possible during maintenance operations to move the outer cowl and the internal fixed structure towards the rear and therefore away from the front cowls to get at the engine.

A control system includes an actuator, a locking/unlock device, a central control valve, first and second control valves, and a spool control valve. The actuator is arranged so as to move a door of a thrust reverser between direct jet and reverse jet positions. The locking/unlocking device unlockable under load allowing locking and/or unlocking of the door. The locking/unlocking device is movable between a closure position in which it holds the door in the direct jet position and an opening position in which the door is released. The first and second control valves each fed by the central control valve. The spool control valve fed at least by the first and second control valves. The spool control valve is configured so that a pressure difference between two inlets of the first and second control valves provides a displacement of the spool control valve between first and second stable positions.

The subject matter of this specification can be embodied in, among other things, a thrust reverser synchronization shaft lock system includes a rotatable shaft comprising at least one radial prong extending radially from the shaft, a hydraulic lock assembly that includes a housing, a piston head having a lock recess, a piston rod extending radially away from the shaft and configured to be urged by the piston head to move the first piston rod end out of engagement with the radial prong to selectably permit rotation of the shaft, and a bias member configured to urge the first piston rod end into engagement with the radial prong, and an electric lock assembly that includes a lock pin and an electric actuator configured to controllably extend and retract the lock pin in and out of engagement with the lock recess.

An actuation device for a thrust reverser includes thrust-reversal movable elements carried by a nacelle and displaceable between a retracted and deployed position. The actuating device includes two actuators mounted on the nacelle and connected to a motor and to the movable elements. The actuation device drives the movable elements in a retraction or deployment direction over a course of the actuators between the retracted and deployed position. The actuation device further includes locks for locking the movable elements in the retracted position and antideployment members associated with the actuators which allow free operation of the actuators in the direction of retraction and retain the actuators in the direction of deployment. The antideployment bodies further provide free operation of the actuators in the direction of deployment over part of the actuators stroke that corresponds to a shift from an over-retraction position to the retraction position of the movable elements.

The subject matter of this specification can be embodied in, among other things, a linear actuator lock apparatus having a housing having an inner surface defining an axial cavity having a first housing portion where the axial cavity has a first lateral size, a second housing portion having a second, larger lateral size, and a face from the first housing portion to the second housing portion, a lock assembly having a lock carrier configured for movement within the cavity between a first position and a position, and a lock finger affixed to and extending away from the lock carrier, where the second finger end is configured to contact the face when extended and fit within the first housing portion when retracted, and a sleeve configured to move between a position in which the lock finger is permitted to extend and a position configured to contact and retract the lock finger.