Abstract: An exhaust nozzle assembly provides fluidic thrust vectoring of the primary stream to enhance aircraft maneuverability. The exhaust nozzle assembly includes a cooling air passage that supplies cooling air to a plurality of cooling holes that generate an insulating layer of air. A vector slot injects cooling airflow into the exhaust passage normal to the primary stream. A cover plate partially blocks the vector slot to direct cooling airflow into the exhaust passage that in turn directs portions of the primary stream.

Abstract: An actuator arrangement comprises an actuator having a rotatable drive input, a motor, and a drive transmission arrangement for transmitting rotary drive from the motor to the rotatable drive input of the actuator, wherein the transmission arrangement includes a telescopic drive coupling.

Abstract: An actuator arrangement comprising a motor arranged to drive an input member, an extendable actuator having a rotatable shaft, a first drive transmission operable to transmit drive between the input member and the shaft when the shaft is under compression, and a second drive transmission operable to transmit drive between the input member and the shaft when the shaft is under tension, wherein the second drive transmission includes a ratchet mechanism.

Abstract: A retractable thrust vector control system (10) for a rocket motor (26) that can generate an exhaust plume comprises at least one control vane (12) connectable to an attitude control assembly (20) that rotates the vane (12) about a control axis (44). The system also includes a retraction mechanism (14) for withdrawing the control vane (12) along the control axis (44) from an extended position at least partially within a path of a rocket exhaust plume and a retracted position substantially out of a path of a rocket exhaust plume.

Abstract: An adapter device for controlling a rocket engine nozzle under conditions of external pressure that can lead to the jet separating inside the nozzle, the nozzle being fitted with a diverging portion that is movably mounted relative to a stationary portion of the nozzle, thrust deflection then being achieved by swivelling the diverging portion so as to deflect the jet of combustion gas in contact with the inside wall of the diverging portion. The device includes a structure disposed inside the diverging portion in such a manner as to reduce the diverging nature of the flow section thereof and to increase the bearing area of pressure forces exerted by the jet on the diverging portion during swivelling thereof.

Abstract: The present invention relates to an air compression type engine for aviation. The conventional aircraft engine is complicated in structure, consumes expensive aero fuel, and produces extremely loud noise during operation. Therefore, the present invention employs a turbo-charged air compressor to generate high temperature and high pressure gas in the pressure chamber, and uses the reaction thrust force generated by ejecting the compressed air through the nozzle to make the aircraft vertically take off/land, suspend in the air and fly forwardly. Benefited from the simple structure, the manufacture cost of the aircraft engine can be dramatically decreased. Vertically raising and landing the aircraft can be achieved by changing the ejection directed of the compressed air in the pressure chamber. The commonly used gasoline or diesel, which is cost saving and capable of combusting with a high combustion value, can be used instead of the expensive aviation kerosene. Further, the generated noise is quite small.

Abstract: A device for controlling a gas flow comprises an outlet part which defines an internal space for the gas flow and a body arranged in the internal space in the vicinity of the outlet of the outlet part, a gap being formed between the body and the inner boundary wall of the outlet part. At least one opening is provided at the outlet of the outlet part for injection of a fluid into the gas flow for the purpose of controlling the direction of the gas flow out of the outlet part.

Abstract: Disclosed is a jet vane thrust vector control (JV-TVC) system. A general system has many problems in design techniques considering actual operation environments, and does not have reliability in component assembly design. The JV-TVC system improves thrust vector control and high angle of attack maneuvering performance of a missile by allowing rotational angles of jet vanes to maximum ±30°, precisely controls the thrust vector of the missile by preventing damages of components for the designated flight time of the missile, and improves precision and reliability in the assembly process by modularization.

Abstract: A nozzle device defines a passageway including an outlet to discharge working fluid to produce thrust. This device includes a vectoring mechanism having three or more vanes pivotally mounted across the passageway and a linkage pivotally coupling the vanes together. This linkage includes a first arm fixed to a first one of the vanes to pivot therewith about a first pivot axis, a second arm and a third arm fixed to a second one of the vanes to pivot therewith about a second pivot axis, and a fourth arm fixed to a third one of the vanes to pivot therewith about a third pivot axis. A first connecting link pivotally couples the first arm and the second arm together, and a second connecting link pivotally couples the third arm and the fourth arm together. The relative angular positioning of the arms with respect to the corresponding pivot axes and/or the arm links can be varied to define different vectoring schedules with the mechanism linkage.

Abstract: A device for controlling propulsive gas mixing at an outlet of an aircraft jet engine, wherein propulsive jets are composed of a hot primary jet exiting from a nozzle of the jet engine and a secondary flux flowing between an external wall of the nozzle and an internal wall of the jet engine including a divergent trailing edge on the wall that generates conditions of a separation of the primary jet close to an existence limit value and a primary jet controller that enables control of passage of the primary jet from a separated state to a reattached state, and vice versa.

Abstract: An aft FLADE gas turbine engine including a fan section drivenly connected to a low pressure turbine section followed by an aft FLADE turbine having at least one row of aft FLADE fan blades radially extending across a FLADE duct circumscribing the aft FLADE turbine, and at least one thrust vectoring nozzle in pressurized fluid flow receiving communication with the FLADE duct. One embodiment of the engine includes spaced apart right and left hand FLADE exhaust nozzles in pressurized fluid flow receiving communication with the FLADE duct and offset from a main engine exhaust nozzle located downstream of the aft FLADE turbine. Right and left hand valves disposed in right and left hand ducts extending between a FLADE airflow manifold in pressurized fluid flow receiving communication with the FLADE duct may be used to vector thrust. The right and left hand FLADE exhaust nozzle may be fixed or thrust vectoring nozzles.

Abstract: The nozzle comprises a moving diverging portion (20) and a static portion (16) secured to the rear end wall of the combustion chamber (12) of the engine. A cardan mount jointed link device connects the moving diverging portion of the nozzle to the static portion, the moving diverging portion and the static portion being in mutual contact via respective spherical surfaces (24a, 16a), and an actuator device (50a, 50b) acts on the moving diverging portion of the nozzle so as to be able to vary the direction of the thrust vector of the engine by modifying the orientation of the nozzle with sliding of the spherical surfaces one on the other. Resilient return means (62, 64) are interposed between the moving diverging portion (20) of the nozzle and the static portion (16) and act on the moving diverging portion in order to urge it towards the static portion so as to keep the spherical surfaces (24a, 16a) in mutual contact for any desired orientation of the nozzle.

Abstract: A device for controlling propulsive gas mixing at an outlet of an aircraft jet engine, wherein propulsive jets are composed of a hot primary jet exiting from a nozzle of the jet engine and a secondary flux flowing between an external wall of the nozzle and an internal wall of the jet engine including a divergent trailing edge on the wall that generates conditions of a separation of the primary jet close to an existence limit value and a primary jet controller that enables control of passage of the primary jet from a separated state to a reattached state, and vice versa.

Abstract: A method for assembling a flap system for a gas turbine engine exhaust nozzle including a plurality of backbone assemblies facilitates extending a useful life of the exhaust nozzle. The method includes providing a flap basesheet having a width defined between a pair of side edges that are coupled together by a leading edge and a trailing edge, and including at least one stiffener that extends between the basesheet side edges and includes an intermediate portion that has a width that is smaller than that of the basesheet and is at least one of bonded to and formed integrally with the basesheet, and coupling the basesheet to the gas turbine engine with a backbone assembly.

Abstract: Control apparatus for a nozzle for a rocket or other vehicle having a combustion chamber with a propellant therein in communication with the nozzle, the nozzle having a throat and a pair of bores extending into the throat The bores may be in opposed or any other suitable relation. A pair of plungers are slidably mounted in the bores and are movable between an open position wherein they are disposed outside of the throat and a closed position wherein they extend into the throat to substantially close it. The plungers have a width or diameter substantially the same as the width or diameter of the throat. Actuator devices are provided for moving the plungers independently of each other to control thrust by controlling the flow of combustion gases through the throat and the pressure in the combustion chamber. The movement of the plungers can also be used for thrust vector control.

Abstract: A propellant utilization system for a space vehicle having at least a first thrust source and a second thrust source. The propellant utilization system utilizes a common set of algorithms to generate mixture ratios for each thrust source as each thrust source becomes active. The propellant utilization system includes a processing system comprising sequencer logic, propellant logic, and mixture ratio logic. The sequencer logic determines when a thrust source is active, e.g. one of the first and second thrust sources, and provides flight parameters for the active thrust source to the propellant logic and the mixture ratio logic. The propellant logic processes information from propellant sources connected to the active thrust source, using the flight parameters for that thrust source, to determine an amount of remaining propellant in each source.

Abstract: A jet engine nozzle having a pair of pivoting extension arms and a pair of pivoting shells connected to a jet pipe is provided. The first extension arm is pivotally connected to the jet pipe at a first location, while the second extension arm is pivotally connected to the jet pipe at a second location. Each shell is pivotally connected at both the first and second locations. An axis of rotation associated with the first location is coaxial to an axis of rotation associated with the second location. Independent actuation means are provided to rotate the extension arms and the shells, thereby enabling adjustment of the thrust-vector angle or the exhaust area of the nozzle.

Abstract: A multi-stage pilot valve is disclosed for selectively supplying a working fluid to and venting from a reaction jet main stage actuation chamber. In a preferred embodiment of the invention, the pilot valve comprises a solenoid actuated ball and socket flapper valve having a pressure inlet, an exhaust outlet and a service port. The first stage service port is in fluid communication with a second stage actuation chamber. A piston disposed in the second stage actuation chamber operatively engages a ball member of a ball-and-seat type valve comprising the second stage valve. The second stage valve also comprises a pressure inlet, an exhaust outlet and a service port. The piston and ball are sized relative to each other such that when the second stage actuation chamber is pressurized by the first stage, the force is sufficient to seat the ball against the second stage pressure inlet.

Abstract: Various joints within a duct assembly to allow relative movement between portions of a fluid system which are interconnected by this duct assembly are disclosed. This duct assembly is particularly suited for interconnecting a rocket fuel tank and rocket engine of a space travel vehicle. In any case, this duct assembly includes a pair of duct suctions, each of which includes a gimbal on an end thereof. The opposite ends of these two duct sections are disposed in a telescope-like arrangement with a slip joint therebetween to allow the duct sections to move at least generally axially relative to each other. This slip joint includes a pair of longitudinally spaced bushings, between which are disposed a plurality of annular seals. The bushings inhibit contain between the two duct sections by maintaining the same in spaced relation.

Abstract: This invention describes vertical take off and landing (VTOL) propulsion systems that develop a forward flow of air through the air intake ducts during vertical takeoff and landing. This forward air flow in the air intake ducts is developed by a internal duct system, reversing the rotation of the fan, or altering the blade pitch of a variable pitch fan.

Abstract: An aircraft having a powerplant with an aft-directed main propulsion outlet means for providing forward thrust, and further including duct means having an inlet for receiving at least a proportion of the efflux from said main propulsion outlet and extending forwardly to an auxiliary outlet disposed adjacent or forwardly of the centre of gravity of the aircraft, said auxiliary outlet being arranged to exhaust efflux with at least a vertical component.

Abstract: A variable area exhaust nozzle with a variable thrust vector angle for a turbo-fan engine and mounted on the aft portion of the nacelle which wraps said engine. The nozzle may include a fixed structure having at least two lateral arms separating two radial cutouts. The cutouts are positioned one above the other, one being located above the engine axis, the other one below the engine axis. At least two shells close the fixed structure cutouts and are pivotally mounted on the fixed structure to form a portion of the exhaust nozzle of the engine. A sealing means ensures fluid tightness between the shells and the fixed structure for any angular position of said shells. Actuator means are provided for pivoting the shells either to a symmetrical configuration for changing of the value of the exhaust area of the nozzle or to an unsymmetrical configuration for changing the angle of the thrust vector of the exhaust nozzle.

Abstract: An integrated system for missile steering, which uses both jet reaction control (JRC) and aerofin control systems, is provided with a variable coupling mechanism for adjusting the relative responsiveness of the two systems in accordance with the pressurization state of the JRC system pressure chamber. In one embodiment, the pivoting action of a joystick which actuates the gas flow control pintles of the JRC system is permitted only under sufficient pressurization of the pressure chamber. In a second embodiment, the extent to which the pintles protrude from their controllable housings is adjusted according to the pressure in the pressure chamber. In this manner, when JRC is undesirable or is unavailable, the missile aerofins are permitted their full range of motion without being constrained by the pintles.

Abstract: Divergent petal arrangement for convergent-divergent nozzles with thrust vectoring capability through changes in the divergent section geometry, in which the position of each slave divergent petals 4 is determined by a centering mechanism 31, made up by two centering bars 14 and 27 that slide across the sled elements 17 and 18 of the master divergent petals 2, fix a centered axial position between divergent master petals 2 and by a hanger element 13 that collides with the stop elements 25 of the master divergent petals limits the displacement to another axial position, avoiding at the same time and in conjunction with the centering mechanism 31 the displacement of the slave divergent petal 4 away from the master petals 2 when the pressure forces act from the air towards the gas side.

Abstract: A gas turbine engine is provided with a translatable cowl and a cascade structure which is nested within the translatable portion of the cowl. The cascade structure comprises a pair of C ducts which are exposed upon translation of a portion of the cowl. The C ducts are capable of rotation about an axis parallel to the longitudinal axis of the engine thus allowing access to the core of the engine.

Abstract: A method is provided to ensure that a combustion turbine power generation system may operate at maximum allowable power at elevated ambient temperature and/or at low air density.

Abstract: A thrust directing mechanism to vector thrust and control discharge throat area with a number of vanes mounted across the passage. The mechanism includes a control link pivotally coupled to each of the vanes. The control link is selectively movable to correspondingly pivot the vanes and has at least two degrees of freedom corresponding to a two coordinate position. A desired orientation of the vanes may be determined as a function of the two coordinate position. The discharge exit area is contracted by adjusting convergence of the vanes. During convergence, the vanes are pivoted to various pivot angles selected to optimize thrust efficiency when contracting the throat area.

Abstract: A turbofan engine is provided with a conventional air by-pass duct communicating with a plenum chamber downstream of the engine core, vectoring nozzles upstream of the by-pass duct, and a non-vectoring nozzle and a jet-pipe exhausting from the plenum chamber. In conventional forward thrust mode the two sets of nozzles are closed and the jet-pipe is open. In lift thrust mode the jet-pipe is closed and the two sets of nozzles are open, the non-vectoring nozzle providing vertical thrust. The closure member for the vectoring nozzle is arranged, when open, to divert turbofan air to the vectoring nozzles which would otherwise have passed along the by-pass duct, and to divert to the vectoring nozzles exhaust gases from the plenum chamber that are constrained to flow in reverse along the by-pass duct. The non-vectoring nozzle is sized to permit a suitable split between gases exhausting there through and gases reverse flowing along the by-pass duct.

Abstract: A flow diverting mechanism for the twin duct offtakes or coannular offtake for a turbo fan engine powering aircraft with either thrust reversing or short takeoff and vertical landing or both capabilities includes a rotary drum mounted between the turbine and afterburner sections and includes ports complementing the inlets in the offtakes to divert the core stream through the offtakes and passages to proportion the fan discharge air utilized for cooling purposes in the engine to cool the liner and walls of the offtakes and the engine components located downstream of the rotary drum while assuring separation of the core stream flow and fan air flow.

Abstract: An actuation activation system for an aircraft engine thrust reverser system is provided including an improved locking actuator (29), a sleeve sensor mechanism, and auto-restow control logic. The locking actuator (29) includes a lever (57) corresponding to whether the actuator is locked or unlocked. A slide-by first proximity sensor (45) is positioned near the lever and set to normally far and triggering near. The first proximity sensor produces a first trigger signal for use in the auto-restow control logic. The sensor mechanism includes a second slide-by proximity sensor and a target in communication with a thrust reverser translating sleeve. The second sensor is connected to the forward side of an engine torque box. A preferred embodiment sensor mechanism (78) is provided and includes a pivotable target arm (96) having a proximal end (98), a distal end (100), and a middle portion pivotably connected to fixed engine structure, preferably torque box (30).

Abstract: An electronic assembly that includes a plurality of electronic substrates that are plugged into a polygonal shaped motherboard. The polygonal shape of the motherboard minimizes the electrical path between electronic substrates while providing enough space between adjacent substrates to allow a fluid to sufficiently remove heat generated by integrated circuits of the substrates.

Abstract: A method and apparatus are provided for controlling rocket and/or jet engine thrust by producing a strong electric, magnetic or electro-magnetic field, and applying the field to deflect the thrust stream as it exits from the engine until the desired thrust vector is obtained. The method of modifying an exhaust plume produced by combustion of fuel and ejected from an exhaust nozzle of a vehicle comprises the steps of: generating a field and producing a flow of electrons across the stream of the exhaust plume for interacting with charged ions and particles in the exhaust plume to deflect the direction of the exhaust plume, and controlling the magnitude and extent of deflection to steer the vehicle to a desired course.

Abstract: A ducted fan gas turbine engine is provided with a thrust reverser which comprises doors which deflect the fan exchaust efflux. Each door is pivotably attached at its downstream end to a common support member by a frangible coupling. In the event of an unintended in-flight deployment of the thrust reverser, the frangible couplings fracture to permit the doors to move to a non-thrust deflecting position.

Abstract: A thrust vectoring axisymmetric vectoring exhaust nozzle having universally pivoting divergent flaps is provided with a surrounding thermal shield of overlapping outer flaps and seals generally disposed in an aftwards converging conical arrangement and having a means for changing its shape from axisymmetrical to asymmetrical. Additional thermal and cooling protection is provided by a series of ejector slots located on the divergent universally pivotal flaps and adjacent interflap seals of the nozzle to both cool and thermally shield the flaps and seals.

Abstract: A variable cycle gas turbine bypass engine includes a first fan 1 located at an inlet to the engine so as to provide air to a compressor 2 driven by a turbine 11 and to a bypass duct 13 surrounding the compressor housing. A second fan 5 located in the bypass duct 13 is driven by a free turbine 12. A controllable area auxiliary air intake 4 and bypass duct blocker doors 3 are located between the first and second fans 1, 5. Control means are effective for selectably operating the bypass duct blocker doors 3 and the auxiliary air intake 4 to vary in operation the bypass ratio of the engine. Thus in conventional wing-borne flight, the intake 4 is closed and the bypass duct 13 is unobstructed, and the combined exhausts from the bypass duct 13 and the turbines 10, 11 and 12 pass to a tailpipe 14, which has a vectorable nozzle 8, to produce forward thrust.

Abstract: A thrust vectoring variable geometry exhaust nozzle for gas turbines, which includes a convergent section (2) followed, in the direction of the flow, by a divergent section (3), both formed by master (4 and 5) and slave petals (41 and 42), whose convergent section (2) defines a throat (15) having a variable area. The divergent section (3) has variable geometry in order to orientate the thrust, and includes a governing and external radial support system for regulating the throat area (15), and a governing system for regulating the vectoring of the thrust. Both system are formed by a single governing system consisting of three annular pieces (6,7 and 8), concentric among themselves and with the axis of the turbine, and by a plurality of linear actuators (9). The master petals (5) of the divergent section (3) are transversely subdivided into at least two segments (5a, 5b).

Abstract: An external flap vectoring mechanism on an axisymmetric gas turbine exhaust nozzle, the external flap vectoring mechanism comprising a plurality of external flaps, each such flap having first and second flaps, the first flap pivotably connected to a sync ring and the second flap pivotably connected to the aft end of the first flap thereby providing for lateral movement of the second flap relative to the first.

Abstract: A sync-ring assembly for use on a axisymmetric gas turbine exhaust nozzle, the sync-ring having a semi-spherical outward surface received within and slidably contacting the cylindrical inner surface of a liner. The sync-ring runs along guide tracks mounted to the case of the nozzle, and is positioned along the liner and rotated with respect to the liner by a plurality of actuators pivotably connected to the sync-ring.

Abstract: A fluid control apparatus for proportionally directing fluid from a single conduct to multiple exhaust ports around the periphery of the duct. A controller is provided which is rotatably supported in the duct by an axial shaft. The shaft supports a radial barrier vane extending along its length and a helical vane forming a single 360.degree. helical wall surrounding the shaft. Rotation of the controller exhaust to shaft axis directs the fluid to the appropriate exhaust ports according to its angular position.

Abstract: The present invention provides support for a vectoring ring used to pivot flaps in a gas turbine engine thrust vectoring nozzle. The ring support transfers at least a portion of the side loads acting generated by a gas turbine engine thrust vectoring nozzle to a relatively stationary portion of the engine. The support includes apparatus that provides for allowing two degree of freedom (2 DOF) pivoting or gimballing motion and axial translation of the vectoring ring.

Abstract: A thrust vectoring exhaust nozzle structure for an engine, such as a ramjet, rocket or turbojet, which generates thrust by expulsion of gaseous fuel combustion products along a thrust axis is described which comprises a generally axisymmetric housing defined along a central thrust axis including a wall structure defining an exhaust duct, and an axially spaced radially inwardly convergent portion, throat and radically outwardly divergent portion, and at least one airfoil disposed on the wall structure of the divergent portion and mounted for rotation about an axis substantially perpendicular to the thrust axis.

Abstract: In the preferred configuration, the assembly is characterized in that the lateral and longitudinal thrust reversing loads exerted on the thrust reversing subassembly are transmitted into the fan duct structure which is arranged to in turn transmit these thrust reversing loads into outer structure to which the jet engine and thrust reversing assembly is mounted. In the preferred form, there are vane means which, with the thrust diverting structure in the thrust reversing position, is positioned in the thrust reversing opening to properly direct flow through the thrust reversing opening. Also in the preferred form, the thrust diverting structure is pivotally mounted to the fan duct structure at a lower location so that the thrust diverting structure rotates with a downward component of motion to the thrust reversing position, so that the thrust diverting opening is directed upwardly.

Abstract: An aircraft speedbrake is integrated into a jet engine exhaust nozzle. A first set of nozzle flaps which are normally out of the airstream, are extended into the airstream to create drag on the airframe and thereby act as speedbrakes. A second set of nozzle flaps are opened when the first set of nozzle flaps are extended into the airstream, to simultaneously spoil the thrust of the engine.

Abstract: An engine end and thrust reversing assembly comprising an annular thrust diverting structure which in the cruise configuration is a rearward extension of a fan duct cowl structure. For thrust reversal, the thrust diverting structure is swung rearwardly and inwardly about an inboard hinge axis to form a laterally and forwardly directed thrust reversing opening. A transversely curved blocking plate is pivotally mounted about a vertical axis to the fan duct structure, and in the cruise configuration it is positioned adjacent to a forward extension of the thrust diverting structure so as to surround a portion of the exhaust passageway. In the thrust reversing position, the blocking plate is swung to a position where it extends across the exhaust passageway defined by the thrust diverting structure.

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: Disclosed is an apparatus and a method for cooling a rotatable convergent side disk in a two-dimensional nozzle for a gas turbine engine, in which coolant is supplied and exhausted through concentric conduits, the cooling requirements of a liner assembly are reduced by use of a thermal barrier coating, and exhaust gas from the nozzle is prevented from aspirating into the side disk by use of a liner which is impervious to the exhaust gas.

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: An interflap segmented seal is provided for use between adjacent flaps of an axisymmetric vectorable exhaust nozzle in order to minimize flow loss therebetween when the flaps are pivoted through different angles in order to turn the exhaust flow and vector the thrust. The overlapping seal segments are mounted to a backbone having an elliptical cross-section by a flange with a lobed hole in it through which the backbone passes. Spacers between the flanges axially position the individual segments from each other. Variable movement between adjacent flaps produces different angles between the sealing edges of the flaps which are often skewed with respect to each other and the flexibility afforded by the seals of the present invention allows the seals to minimize the leakage between the flaps and the seals.

Abstract: A thrust vectoring axisymmetric convergent divergent variable exhaust nozzle is provided with a universally pivoting joint between the divergent and convergent flaps and actuating the linkage mechanisms for changing the divergent nozzle section from axisymmetrical to asymmetrical by pivoting the divergent flaps in the radial and tangential directions with respect to the axisymmetric nozzle centerline in a controlled manner.

Abstract: Apparatus and a corresponding method for controlling the attitude of a space vehicle during operation of its propulsion engines, without gimbaling of the engines. Two engines are differentially throttled, one above and one below a nominal thrust setting of the engines, in response to an error signal indicative of the difference between an actual attitude angle and a desired attitude angle. Three or four engines can be used to control attitude about two orthogonal axes, or a greater number of engines can be used for redundancy.