Abstract: Doors sealing radial flow ports are opened by rotation which slides the doors away from the ports. All doors rotate about a longitudinal centerline of the aircraft. Each flow port has its inlet seal surface with a center of curvature offset from the longitudinal axis. Rotation of the door toward the open position relieves and releases contact between the door and the port inlet seal surface.

Abstract: A thrust reverser system for fan jet type aircraft gas turbine engines using a "sliding hinge" arrangement for moving blocker doors between the stowed and deployed positions. Blocker doors fill a plurality of radially arranged openings in an engine nacelle near the aft end of the nacelle. In the stowed position, each blocker door forms and inner and outer streamlined surface corresponding to the nacelle walls, with no actuator mechanisms extending into the air flow stream within the nacelle. Each blocker door is moved to the deployed position by an extensible rod, such as a hydraulic piston rod, extending between the nacelle near the forward edge of the opening and the approximate centerline of the door. As the door begins to move rearwardly, slider pins on the door edges slide along tracks on the adjacent nacelle islands between adjacent openings.

Abstract: A thrust reverser assembly is disclosed for a wing mounted gas turbine engine exhaust nozzle having an outlet for discharging exhaust gases over a surface of the wing. The assembly in accordance with a preferred embodiment includes a deflector having forward and aft ends, and first and second sides joined together by a base. The deflector is positionable in a stowed position around the exhaust nozzle so that the aft end is aligned generally with the nozzle outlet for allowing substantially unobstructed discharge of exhaust gases therefrom, and in a deployed position for changing direction of exhaust gases for thrust reversal. A pair of bellcranks are positioned adjacent to respective ones of the deflector sides and actuators are povided for rotating the bellcranks for moving the deflector between the stowed and deployed positions.

Abstract: A jet engine for an aircraft has a thrust reverser including one or more doors which define at least a part of the throat of the engine's nozzle. The engine further includes a latch mechanism for retaining the doors in a stowed position. The doors may be deployed for reversal of engine thrust, but are also capable while stowed of being pivoted in a limited way to change the cross-section area of the throat of the nozzle.

Abstract: A thrust reverser for jet engines comprising a pair of symmetrical thrust reverser door members which are pivotally mounted on an engine about an axis which is substantially diametrical with respect to the exhaust nozzle of the engine, the doors having scarfed trailing edges in order that they may pivot between stowed and deployed positions, a pair of pivotally mounted half-shells surrounding at least the trailing edges and defining a planar exhaust outlet for the engine; the pivot axes for the doors is movable in order to vary the area of the exhaust outlet defined by the half-shells depending upon the particular stage of flight.

Abstract: A thrust reverser for use with a jet engine comprising a pair of symmetrical thrust reverser doors, each of which doors are pivotally attached to an attachment element on the jet engine pipe so as to be pivotally movable between reversing and non-reversing positions, each of the doors having a scarfed trailing edge portion so that in the reversing position; the trailing edge portions of the doors are in abutting contact; a pair of half-shells, one being associated with and surrounding the trailing edge portion of each of the doors, the half shells being pivotally attached to the attachment element and cooperatively forming a planar exhaust outlet for the jet engine.

Abstract: A gas turbine engine is provided with a thrust reverser. In order to avoid inadvertent operation of the thrust reverser when the gas turbine engine is not running, a safety switch is provided on the engine at a position remote from the thrust reverser. The thrust reverser control system is arranged so that when the engine is not running the thrust reverser will only operate when the safety switch is being manually operated.

Abstract: Increased aircraft control is achieved by combining reverse thruster operation with splay capability. Each of the four door sets has a pair of vanes controllable to various parallel positions. Maximum opening at 26.degree. from the vertical decreases in each direction from the maximum position. The vanes may be controlled to effect yaw and pitch control while maintaining a constant total effective flow area. Back pressure on the turbine is thereby unaffected.

Abstract: Increased aircraft control is achieved by combining reverse thruster operation with splay capability. Each of the four door sets has a pair of vanes controllable to various parallel positions. Maximum opening at 26.degree. from the vertical decreases in each direction from the maximum position. The vanes may be controlled to effect yaw and pitch control while maintaining a constant total effective flow area. Back pressure on the turbine is thereby unaffected.

Abstract: An improved version of a vectored thrust ducted propeller tail assembly or "ring tail" for rotary wing aircraft in which a deflecting surface or surfaces is pivotally mounted behind the shrouded propeller in the tail duct for rotation transversely of the duct interior in deflecting the propeller slip stream transversely of the duct establishing a transversely directed thrust for providing rotor torque counteracting and aircraft yaw control. In the improved version the slip stream deflecting surfaces are pivotally supported to extend transversely across the duct rear exit in both directions as will deflect the propeller slip stream either out the left or the right sides or out both the left and right sides of the duct end.

Abstract: A thrust reverser for aircraft fan jet engines using a plurality of sets of deflector and blocker doors filling openings through the engine nacelle during normal engine operation. During thrust reversal, the doors substantially block air normal fan air flow through the duct between engine cowling and the outer nacelle and deflect it out through the nacelle openings in a reverse direction. An actuator and hinge assembly moves each blocker door from a stowed position flush with the inner nacelle surface to a deployed position blocking air flow between nacelle and cowl. Simultaneously, an actuator and hinge assembly moves each deflector door from a stowed position flush with the outer nacelle surface to a deployed position receiving air from the blocker doors and deflecting that air flow in an outwardly and forwardly direction. The actuator and hinge assemblies are substantially out of the path of air flow in both the stowed and deployed positions.

Abstract: A pivot door type aircraft turbine engine thrust reverser which includes a pair of pivoting panels on the inner side of the door. The panels are positioned alongside the door actuation mechanism. The panels form a flush surface along the fan duct flow path when stowed during normal engine operation in flight. When the door is deployed in thrust reversing mode, one end of the door moves to at least partially block airflow through the duct and divert it out along the door through an opening uncovered by door deployment. During door deployment, a linkage moves the panels toward the outer surface of the door, exposing a door deflector plate to the airflow. Air flows along the door, then along the panel, out through the opening, then impacts the deflector plate which deflects the airflow in the reverse direction.

Abstract: A thrust reverser is provided for a gas turbine engine and exhaust nozzle supported by an aircraft wing, the exhaust nozzle having an outlet for discharging exhaust gases over an outer surface of the wing. The thrust reverser in accordance with a preferred embodiment includes a deflector having forward and aft ends, and first and second sides joined together by a base. The deflector is positionable in a stowed position around the exhaust nozzle so that the aft end is disposed forward of the nozzle outlet for allowing substantially unobstructed discharge of the exhaust gases from the nozzle outlet, and in a deployed position for changing direction of the exhaust gases for thrust reversal. A torque bar is fixedly joined to the first and second deflector sides and has a longitudinal centerline axis. The torque bar is rotatably joined to the wing, and the deflector is rotated about the torque bar centerline axis for being positioned in the deployed and stowed positions.

Abstract: A thrust reverser in a two dimensional jet engine exhaust nozzle employs a plurality of reverser apparati that maintain a constant flow throat area, for example, in the reverse throat mode. A single reverser apparatus includes an actuator that operates through a lever upon linkage and a coupler to drive a set of parallel vanes and at least one independent vane. The parallel vanes are connected by a parallelogram of links to the coupler. The independent vanes move in a manner as defined by a cam having a preselected path therein that causes the independent vanes to move in a desired manner to provide the constant throat area.

Abstract: An apparatus for influencing a flow of air through a passageway defined between an inner wall and a double outer wall that includes first and second walls each formed with an opening, comprises a first door, a second door, vortex generation means positioned between the first and second walls and adjacent the upstream end of the opening in the first wall, and an actuator pivotally attached to the first and second doors. The actuator has a first condition wherein the first and second doors close the openings in the first and second walls respectively and has a second condition wherein the first door is at the downstream end of the opening in the first wall and extends across the passageway and directs the flow of air through the opening in the first wall, and the second door is at the down-stream end of the opening in the second wall and deflects the flow of air through that opening.

Abstract: Ports through the wall of the exhaust duct and the wall of the surrounding cooling air duct, connect the exhaust duct and reverse thrust ducts. Door sets seal these ports. The door sets are contrarotated around the exhaust duct providing a symmetrical opening of the ports.

Abstract: A device for coupling a rotary member to an axially movable input stem of a linear displacement transducer comprises an axially movable element which is coupled to the stem and threadedly engages the rotary member. The axially movable element is restrained against rotation by spring loaded detents and has abutments which can engage a lug on the member when the element reaches its limiting axial positions. This engagement causes the element to be rotated with the member and input to the transducer is arrested.

Abstract: A thrust reverser assembly is disclosed for a wing mounted gas turbine engine exhaust nozzle having a fixed outlet for discharging exhaust gases over a surface of the wing. The assembly in accordance with a preferred embodiment includes a deflector having forward and aft ends, and first and second sides joined together by a base. The deflector is positionable in a stowed position around the exhaust nozzle so that the aft end is disposed forward of the nozzle outlet for allowing substantially unobstructed discharge of exhaust gases therefrom, and in a deployed position for changing direction of exhaust gases for thrust reversal. Two pairs of first and second bellcranks are positioned adjacent to respective ones of the deflector sides and means are provided for rotating the bellcranks for moving the deflector between the stowed and deployed positions.

Abstract: A gas turbine jet engine is disclosed with a fan delivering into a bypass duct to generate mainly propulsion thrust, and with a thrust reversing device having flaps which for reverse thrust operation pivot into the fan air stream and cooperate with an axially extended extreme section of the outer wall of the bypass duct to uncover delection ports arranged at breakthroughs in the outer wall. The extreme section of the outer wall and the thrust reverser flaps are linked one with the other for relative movement between them such that in a first phase of actuation relative to a fixed extreme nozzle section, the extreme section provides an additional fan nozzle area which communicates with the inlet flow areas formed by the flaps relative to the bypass duct.

Abstract: A method of creating thrust reversal for an engine having counter-rotating forward and rear propeller blades. The forward blades are set at a positive angle of attack to produce an orderly flow of air toward the rear blades. The rear blades are set at a negative angle of attack to produce reverse thrust. The net effect is that the thrust produced by the rear blades overbalances that of the forward blades to produce net thrust reversal.

Abstract: The present invention relates to an apparatus for controlling an air cushion vehicle (trade name, Hovercraft) of a vehicle to be driven by air flowing pressure, in which rudders are provided along both side walls of a propulsion fan duct, the rear sides of the rudders are bent toward the outside of the propulsion fan duct to perform the abrupt braking at the time of linearly moving and reverse moving of the air cushion vehicle, and the handle column for turning the direction is tiltably provided to easily move reversely the air cushion vehicle by the same handle steering operation.

Abstract: A movable cowling for an aircraft is disclosed having a stationary fairing portion attached to an engine support pylon and a movable cowling portion. The movable cowling portion defines a generally longitudinally extending slot to accommodate the stationary fairing portion when the movable cowling portion is in its closed position to enclose the aircraft engine. The movable cowling portion, which may be generally annular in shape and have a generally "C"-shaped cross sectional shape, is attached to the engine by way of a telescoping beam. A portion of the beam is attached to the movable cowling and a second portion of the beam is attached to the engine. The movable cowling moves in a direction generally parallel to the longitudinal axis of the engine such that it has no portions requiring lifting about a hinge axis. A locking mechanism is provided between the movable cowling portion and the stationary fairing to lock the movable cowling portion in its closed position.

Abstract: A propulsive air stream deflecting apparatus for an air cushion vehicle is provided on the hull of the air cushion vehicle for arcuately deflecting the propulsive air stream from the open rear end of the air duct, mounted to the hull. The deflecting mechanism provides a steering thrust to the air cushion vehicle. The deflecting mechanism is pivotable about a vertical pivot mounted to the hull between a propulsive thrust producing position, where the deflecting mechanism is located away from the propulsive air stream issuing from the rear open end of the air duct, and a forward thrust producing position where the deflecting mechanism fully covers the rear open end of the air duct for deflecting the propulsive air stream to create the forward thrust to the hull.

Abstract: The present invention relates to a thrust reverser for a turbojet engine that improves the efficiency of the engine in both the forward thrust and reverse thrust operating modes. The invention achieves these goals by providing deflector panels attached to a stationary engine housing structure that are moveable between forward thrust and reverse thrust positions as the thrust reversing doors are moved between their forward thrust and reverse thrust positions. The deflector panels are attached to the housing so as to have a single degree of freedom and are actuated by linkages interconnecting them with the thrust reversing door actuator cylinder.

Abstract: A jet engine for an aircraft has a thrust reverser including one or more doors which define at least a part of the throat of the engine's nozzle. The engine further includes a latch mechanism for retaining the doors in a stowed position. The doors may be deployed for reversal of engine thrust, but are also capable while stowed of being pivoted in a limited way to change the cross-section area of the throat of the nozzle.

Abstract: A thrust reverser is disclosed having a thrust reverser door with an outer door panel pivotally attached to an inner door panel which, in turn, is pivotally attached to an annular housing. The door panels are pivotable about parallel, but displaced pivot axes such that the inner door panel undergoes a greater range of motion between its closed and open positions that does the outer door panel. This enables the inner door panel to be flush with the upstream and downstream portions of the inner housing surface to provide a smooth airflow through the air duct during the forward thrust mode, while at the same time enabling an efficient operation of the door during the reverse thrust mode.

Abstract: An actuation system for pivoting a blocker door and blocking and redirecting airflow through cascades during thrust reversal of an aircraft. The system is operated when an engine nacelle thrust reverser sleeve assembly is opened and then closed.

Abstract: A plurality of cascade vanes (28, 29, 30) pivot in unison for selectably directing a flow of gas (20) therethrough. A flow regulating vane (36) disposed adjacent one end vane of the plurality of cascade vanes (28, 29, 30) pivots (46) counterrotationally with respect to the cascade vanes (28, 29, 30) for maintaining a constant collective gas flow area.

Abstract: A sensor (20) is mounted on a fixed torque box (8) carried by a fixed portion of an engine nacelle (6). A target plate (40) is resiliently mounted on a thrust reverser translating cowl (10). A cylindrical sleeve (32) is attached to the sensor (20) and surrounds its outer sensing end (22). The outer radial surface (34) of the sleeve (32) is spaced beyond the sensing end (22) a predetermined distance (100). The surface (34) contacts the target plate (40) when the cowl (10) is in its closed position. The resilient mounting of the plate (40) compensates for inaccuracies in the installation of the plate (40) and allows relative movement between the cowl (10) and the plate (40) when the cowl (10) is in its closed position to maintain a fixed gap (100) between the plate (40) and the sensor (20).

Abstract: A variable-area, thrust vectoring, and thrust reversing aircraft propulsion nozzle includes mechanization which is uniquely simple, strong, and lightweight, as well as being able to endure the harsh, high-temperature environment of a jet engine exhaust flow. The nozzle employs a minimal number of actuators, and structure which is isolated from reversing thrust forces so that an overall objective of strength, simplicity, and lightweight is achieved by the invention.

Abstract: The aircraft propulsive unit having on the one hand, a fixed central structure in the axis of which is housed a gas generator whose nozzle delivers a hot jet and, on the other hand, an upstream fan or blower concentric with the gas generator and rotating inside an annular channel defined by the fixed structure and by a peripheral cowling or fairing with double wall carried by the fixed structure, the blower providing the forced circulation of a cold flow in the channel for improving the performance of the power unit, the fairing being formed of two parts, the upstream one of which is fixed and surrounds the blower, whereas the downstream one is mobile and slides parallel to the axis x--x' of the generator, the propulsive power unit further having a system for reversing the thrust of the cold flow which is formed of pivoting doors having respectively external and internal walls which, in the retracted position of the doors, are aligned respectively with the external and internal walls of the fairing.

Abstract: A plurality of cascade vanes (28, 29, 30) for directing a flow of gas (20) is provided with at least one flow regulating vane (36) which counterrotates with respect to the cascade vanes (28, 29, 30) over a gas flow vectoring range of motion. The cascade vanes (28, 29, 30) and flow regulating vane (36) corotate when moving through an adjacent stowing range of motion for achieving a stowed, gas flow blocking arangement.

Abstract: A convergent-divergent jet exhaust nozzle has an aft end with an exit area thereat and a throat area spaced from the exit area and forward thereof. The ratio of the exit to throat diameter is from 1.00 to 1.05. Each of two symmetrical blocker doors has an axis coincident with the axis of the nozzle. Each of the blocker doors has opposite forward and rear edges and a surface extending between the edges. Each of the blocker doors is pivotally mounted to pivot about a pivot axis transverse to the axis of the nozzle and disposed downstream of the engine in the nozzle. The pivot axes are in a plane intersected by the axis of the nozzle.

Abstract: An adjustable two-dimensional nozzle is disclosed in which simplified control means are located away from the flow of gasses through the nozzle. The nozzle includes a movable frame located outside of fixed sidewalls and has pivotally attached thereto a pair of upstream or converging nozzle flaps. Upstream edges of the upstream flaps are attached to the movable frame such that the flaps pivot about axes extending substantially perpendicular to the longitudinal axis of the nozzle. Downstream or diverging flaps are attached to the downstream edges of the upstream flaps such that these flaps also pivot about axes extending substantially perpendicular to the longitudinal axis of the nozzle. A cam member extends between each of the movable frames and each downstream flap to control the angular variations of the flaps during movement of the frame.

Abstract: A cascade assembly for directing the gases externally of a jet aircraft engine in a forwardly direction when the engine is in a gas reversing mode. The cascade assembly comprises a plurality of cascade panel sections positioned in a side by side relationship over an opening in the engine nacelle. The panel sections have a plurality of spaced apart curvilinear vanes angled from the centerline of the engine. Longitudinal beams are positioned over the longitudinal edges and adjacent ends of at least one cascade panel section to secure it in place. The beam is "T" configured in the cross-section with feet or pads on each end to overlay the longitudinal outer edge and adjacent end surfaces of the cascade panel section or sections which it is securing in place. The pads or feet on the beam ends include apertures therethrough for securing the beams to aircraft structure. Both the cascade panel sections and beams are constructed of molded plastic or cured composite materials.

Abstract: A convergent/divergent gas turbine engine exhaust nozzle having reverse thrust capability includes a concentric flap (22) and arc valve (36) pivotable about a common axis (34). A method and linkage (48) schedule the opening of the valve (36) in response to rotation of the flap (22) into a blocking position with respect to the normally aftward flow of the exhaust gas (12). The arc valve (36) is accelerated by the linkage (48) to full opening speed prior to unsealing an alternate, thrust reversing flow passage (38).

Abstract: A two dimensional exhaust nozzle for a gas turbine engine having reverse thrust capability includes a pair of spaced apart converging flaps which are able to rotate about their respective axes until their downstream edges meet along the engine centerline to block the flow of gases through the engine and to redirect the flow through fixed area reverser outlet ports. The axes about which each convergent flap rotates are spaced inwardly from their respective convergent flap surfaces. The flaps themselves cover the outlet ports when the flaps are in forward thrust operating positions. The flaps move away from and unblock the outlets as they rotate to their reverse thrust position. The distance between the flap axis and its convergent surface is critical to being able to use short flaps while obtaining large reverser outlet areas.

Abstract: An automatic deflector for deflecting hot exhaust air from a bleed air exhaust port of a jet engine compressor. The deflector deflecting the hot air into the engine's fan duct when the engine is in a thrust reversal mode. The deflector prevents hot air from contacting and damaging the fan duct wall opposite the air exhaust port.

Abstract: An engine nozzle construction having a flap nozzle at the end of an engine exhaust duct, said flap nozzle variably controlling exhaust flow providing a primary flow path, said flap nozzle being movable to a position to direct the exhaust flow from said exhaust duct into a peripheral chamber, said chamber having exit openings around it providing for a secondary flow path for the exhaust flow.

Abstract: A vibration isolation device connected to a drag arm of a blocker door assembly in a jet engine thrust reverser unit. The isolation device providing for preload, travel and vibration dampening of the drag arm on the blocker door assembly.

Abstract: A composite bond cascade for a thrust reverser unit of an aircraft engine nacelle and a method of making the cascade. The cascade made of continuous fibers used in forming vanes and beams of the cascade for reducing weight and improving the overall strength of the cascade.

Abstract: A seal plate rests along the edge of a moveable flap surface and extends outwardly therefrom into contact with a stationary wall to seal the gap between the flap edge and the wall. The seal plate is hinged for rotation to one end of a pivotable support link which is hinged at its other end to the flap. The gas pressure load on the seal plate presses it against the flap surface and also tends to rotate the support link to press the outward edge of the seal plate against the stationary wall.

Abstract: A thrust reverser blocker door assembly for a fanjet engine (34) wherein a plurality of blocker doors (10) are disposed aerodynamically about a peripheral circumferential zone of a central fan duct (46) of the engine in a cruise configuration and are pivoted radially into an annular ring interrupting the fan duct in a thrust reversing configuration for diverting air radially outward and forward through a concentric bypass duct (48), each of the blocker doors (10) being secured for pivotal displacement by an articulated linkage (50) comprising a drag link (62) disposed for arcuate motion about a fixed pivot point (64) at its proximal end, an overcenter link (12) spanning the blocker door (10) and the distal end of the drag link (62) at a longitudinally translatable pivot point (70), and a biasing member (100) for tensioning the articulated linkage (50) and the blocker door (10) radially outward about the translatable pivot point (70) when in the cruise configuration.

Abstract: An exhaust nozzle for a gas turbine engine comprising a duct 17(c) extending along an axis and having at a dowstream end thereof a mechanism for varying the geometry and area of the nozzle. The mechanism 28 comprises an axially translatable member 28 which has a face 29 extending in a direction transverse to the axis of the duct 17(c) against which pressurized gases flowing through the duct acts to balance out the loads on the flaps. A plurality of flaps 38,43 are spaced circumferentially around the axis of the duct. The flaps 38 are pivotally attached to the axially translatable member 28 and are provided with a cam follower 40 that co-operates with a cam 37. The cams 37 are fixed relative to the duct 17(c) and thereby defines the attitude of each flap 38 relative to the member 28. Seal plates 41 and 45 cover the gaps between adjacent flaps 38 and 43 to the seal plates 45. A plurality of struts interconnect the member 28 and the second flaps of the pivotal attachment of the flaps 43 to the flap 38.

Abstract: A thrust reversing system for controlling the fan gases from a thrust producing aircraft engine. The system comprises a first group of blocker doors surrounding the upper longitudinal portion of the engine fan duct; a second group of blocker doors positioned rearward of the first group surrounding the entire engine fan duct; mechanism is provided for translating an upper movable fairing and a lower sleeve section which during translating provides an upwardly directed opening from the fan duct through gas-directing cascades and deploys the blocker doors from a stowed duct wall lining position to a deployed fan gas blocking deployed position.

Abstract: Apparatus for the synchronized displacement of two thrust reversers for two jet engines of an airplane, comprising first and second systems for displacing respective thrust reversers. Each system includes a compressed air motor, a valve controlling the operation of the motor by controlling the flow of compressed air thereto, and an input system for operating each valve to control the displacement of the respective motor. A synchronizing system synchronizes the displacement of the thrust reversers by measuring displacement in the first and second systems at respective corresponding locations and controlling the operation of the first and second motors such that the displacements of the thrust reversers by the respective motors are equalized.

Abstract: The invention relates to a reversing means in a marine-water-jet propulsion unit, which includes a pump (4) having connected thereto a nozzle tube (14) for directing the driving jet of water. The lower wall (14a) of the tube is provided with an opening (16), and the reversing means includes an inner flap (17) and an outer flap (18) arranged to close the opening from the inside and the outside respectively of the tube. The inner flap (17) can be swung about its fore end, as seen in the direction of flow of water through the tube, between the closed position and a position in which it is swung inwardly in the tube (14), in which position the flap (17) completely or partially blocks the flow path through the tube and deflects the water flow completely or partially out through the opening (16) in the wall of the tube.

Abstract: An invention is disclosed for the attachment of a yoke to a laminated material composed of a medial matrix laminated between first and second skins. Two elongated parallel brackets are attached to the laminated material, the brackets each having a first segment fastened to the first skin, a second segment fastened to a first region of the second skin, and a third segment fastened to a second region of the second skin. The first and second regions are separated by a cavity in the second skin. The yoke is positioned in the cavity and fastened to the two brackets to provide a thrust point approximately coplanar with the second skin. The invention can be used to attach an actuator rod at the thrust point when the laminated material is that used in a cowling associated with a thrust reverser in a gas turbine aircraft engine.

Abstract: For a long dual mixer nacelle housing a fan-jet engine powering aircraft, a pair of concentric sleeves sandwiching the cascades to effectuate thrust reversal are synchronously deployed axially to communicate the fan discharge air in the duct with ambient through the cascades. A rack and gear connection between sleeves permits the independent linear motion of each of the sleeves so that the actuation of one automatically actuates the other without the necessity of attaching both to each other.

Abstract: A system for the displacement of two thrust reversers for two jet engines of an airplane. Each thrust reverser has a drive motor operated by compressed air, a valve controlling the flow of compressed air to the motor, a set-point indicator including an input piston controllable by the action of compressed air, a differential transmission, and a feedback system from the motor to the differential transmission. The valve is actuated by the input piston and the motor via the differential transmission. The displacement of the two thrust reversers is halted by a system of stops acting on the input pistons at identical intermediate points in the paths of travel thereof and the displacement is thereafter continued after the thrust reversers have both reached their intermediate points in their paths of travel by deactivation of the stops.