Abstract: A system for modulating air flow in a gas turbine engine is provided. The system may include a seal wall comprising an opening, a seal door configured to slideably engage the seal wall, and an actuator configured to move the seal door over the opening. In various embodiments, the system may include a surface forward of the seal door. The seal door may be configured to seal a passage through the surface and the opening of the seal wall. A track may be disposed under the seal door. The track may comprise cobalt. Rollers may be coupled to the seal door with the rollers on the track. The seal door may comprise a nickel-chromium alloy. A sync ring may be coupled to the seal door. The actuator may be coupled through the sync ring to the seal door.

Abstract: A hinge assembly of a system for operating a door of an aircraft includes a bracket secured to a structure of the aircraft. The bracket includes a first forward joint and a first aft joint separated by a first distance along a first line. A forward link is coupled to the first forward joint. An aft link is longer than the forward link, and is coupled to the first aft joint. A door coupler is secured to a door. The door coupler includes a second forward joint and a second aft joint separated by a second distance that is less than the first distance. The second distance is along a second line that is parallel to the first line in a stowed position. The forward link is further coupled to the second forward joint, and the aft link is further coupled to the second aft joint.

Abstract: A powerplant is provided that includes a pre-burner, a combustor, a power turbine, a mechanical load and a propellant system. The combustor is fluidly coupled with and downstream of the pre-burner. The power turbine is fluidly coupled with and downstream of the combustor. The mechanical load is rotatably driven by the power turbine. The propellant system is configured to direct fluid oxygen and fluid hydrogen to the pre-burner to provide an oxygen rich fuel mixture for combustion within the pre-burner. The propellant system is also configured to direct the fluid hydrogen to the combustor for combustion within the combustor with oxygen within combustion products received from the pre-burner.

Abstract: The inventors introduce the Borissov-Markusic Cycle as the new rocket engine cycle to solve the problem of low efficient open gas generator or tap-off gas generator cycles used to supply power to turbopump. A liquid rocket engine directs turbopump exhaust from a turbopump to a booster engine having an intake to accept ambient airflow, such as a variation of a ramjet, scramjet or dual mode ram scramjet engine. The turbopump is powered by combustion gases, such as from a gas generator or a tap-off manifold interfaced with the liquid rocket engine combustion chamber, and applies energy of the combustion gases to pump fuel and/or liquid oxygen to the liquid rocket engine combustion chamber. The combustion gases have a fuel-rich composition that includes unconsumed fuel from incomplete oxidation so that, upon injection into the combustion chamber of the booster engine, oxidation by ambient air of the unconsumed fuel releases energy to generate thrust with the booster engine.

Abstract: A gas turbine engine includes a core section including a compressor, a main combustor, and a main turbine. Combustion products from the main combustor drive rotation of the turbine and the compressor. A power turbine is fluidly connected to the main turbine and driven by exhaust from the main turbine. The gas turbine engine further includes a fan section having a fan rotor located fluidly upstream of the core section. The power turbine is operably connected to the fan rotor to drive rotation of the fan rotor via rotation of the power turbine. The gas turbine engine includes a bleed arrangement having one or more bleed passages configured to divert a bleed airflow from the compressor around the main combustor and main turbine, and reintroduce the bleed airflow into the power turbine.

Abstract: A vertical-takeoff-and-landing (“VTOL”) aircraft including a non-VTOL aircraft equipped for forward takeoff and flight and a modular boom system interoperably coupled to the non-VTOL aircraft. The modular boom system includes a first modular boom and a second modular boom. The first modular boom includes a first rocket-turbine engine. The first modular boom is mounted to a first wing of the non-VTOL aircraft. The second modular boom includes a second rocket-turbine engine. The second modular boom is mounted to a second wing of the non-VTOL aircraft.

Abstract: A pulse combustor system for operating pulse combustors in anti-phase. The pulse combustor system includes two pulse combustors connected at their combustion chambers by a connecting tube. Each of the pulse combustors has a fundamental oscillation mode and one or more additional oscillation modes when operated in isolation. The connecting tube has a length corresponding to ¼ of the fundamental oscillation mode wavelength.

Abstract: An attitude control system for a guided missile includes a gas generator, an accumulator coupled to the gas generator, and a valve positioned between the gas generator and the accumulator. The gas generator contains propellant that burns to provide hot gas to pressurize the accumulator. The valve is opened to recharge the accumulator with hot gas and closed when it is full. A vent valve can be included to extinguish the propellant in the gas generator. The accumulator can be coupled to thrusters that use the stored hot gas to adjust the attitude of the guided missile.

Abstract: A turboshaft engine includes a core section extending between an inlet and an outlet of the turboshaft engine. The core section includes a compressor, a main combustor, and a main turbine, such that combustion products from the main combustor drives rotation of the turbine and the compressor. A power turbine is fluidly connected to the main turbine and driven by exhaust from the main turbine. A primary bypass is fluidly connected to the inlet and the outlet. The primary bypass directs a portion of an airflow entering the inlet around the core section to the outlet. A secondary bypass is located in the core section and is configured to divert a portion of a core airflow of the core section around the main combustor and the main turbine to the power turbine.

Abstract: Omnivorous solar thermal thrusters and adjustable cooling structures are disclosed. In one aspect, a solar thermal rocket engine includes a solar thermal thruster configured to receive solar energy and one or more propellants, and heat the one or more propellants using the solar energy to generate thrust. The solar thermal thruster is further configured to use a plurality of different propellant types, either singly or in combination simultaneously. The solar thermal thruster is further configured to use the one or more propellants in both liquid and gaseous states. Related structures can include valves and variable-geometry cooling channels in thermal contact with a thruster wall.

Abstract: A dual flow path exhaust assembly for use with a combined turbofan and ramjet engine includes a turbofan engine exhaust duct, a ramjet engine exhaust duct, a combined outlet, and door configured to move between an open position and a closed position to selectively isolate the turbofan engine exhaust duct from the combined outlet.

Abstract: A cooling system for a gas turbine engine may comprise a heat exchanger configured to receive a cooling airflow. The heat exchanger may receive the cooling flow at a cooling flow input of the heat exchanger and output the cooling airflow at an exhaust output of the heat exchanger. An exhaust distribution manifold may be fluidly coupled to the exhaust output of the heat exchanger. The exhaust distribution manifold may define a plurality of openings.

Abstract: A gas turbine engine system includes a boost compressor configured to compress air; a combustor in which the compressed air is mixed with fuel and ignited to generate a stream of combustion gases; and a turbine configured to extract energy from the combustion gases, the turbine being drivingly coupled to the boost compressor and to an output shaft via a differential gearbox configured to apportion an input torque from the turbine between a first output torque applied to the output shaft and a second output torque applied to the boost compressor.

Abstract: A pulse combustor system for reducing noise and/or vibration levels. The system includes a pulse combustor including a combustion chamber, an inlet pipe, an exhaust pipe, and a first fuel injector for injecting fuel into the combustion chamber. The pulse combustor has a fundamental oscillation mode and one or more additional oscillation modes. The system includes at least one pressure sensor for measuring a pressure inside the fuel combustor and/or a at least one fluid velocity sensor for measuring fluid velocity at the inlet pipe or at the exhaust pipe. A controller adjusts a rate of fuel supply to the pulse combustor if the measured pressure and/or the measured velocity is above a predetermined threshold value to reduce excitation of the one or more additional oscillation modes.

Abstract: An attitude control system for a guided missile includes a gas generator, an accumulator coupled to the gas generator, and a valve positioned between the gas generator and the accumulator. The gas generator contains propellant that burns to provide hot gas to pressurize the accumulator. The valve is opened to recharge the accumulator with hot gas and closed when it is full. A vent valve can be included to extinguish the propellant in the gas generator. The accumulator can be coupled to thrusters that use the stored hot gas to adjust the attitude of the guided missile.

Abstract: An adaptive aircraft engine including a first, inner bypass duct inside a core engine of the aircraft engine and a second, outer bypass duct at least partially surrounding the first bypass duct, and adaption means, in particular adjustable nozzles for altering a flowed-through cross-section of the core engine with the first bypass duct and for altering the flowed-through cross-section of the second bypass duct depending on the flying speed. An aircraft having at least one adaptive aircraft engine is also provided.

Abstract: A method of operating a gas turbine engine includes modulating a variable high pressure turbine inlet guide vane of a high pressure spool to performance match a first stage fan section of a low pressure spool and an intermediate stage fan section of an intermediate spool to maintain a generally constant engine inlet flow while varying engine thrust.

Abstract: A turbofan engine includes a core engine, having a high-pressure compressor, a combustion chamber and a high-pressure turbine which are coupled to one another via a high-pressure shaft, at least one fan from which gas is supplied into both a primary flow duct and a secondary flow duct of the turbofan engine, at least one low-pressure turbine arranged behind the core engine, and at least one low-pressure shaft, with each low-pressure shaft coupling a fan to a low-pressure turbine. It has been provided that no low-pressure shaft of the turbofan engine passes through the core engine.

Abstract: The present disclosure relates to an engine having two modes of operation—air breathing and rocket—that may be used in aerospace applications such as in an aircraft, flying machine, or aerospace vehicle. The engine's efficiency can be maximized by using a precooler arrangement to cool intake air in air breathing mode using cold fuel delivery systems used for the rocket mode. By introducing the precooler and certain other engine cycle components, and arranging and operating them as described, problems such as those associated with higher fuel and weight requirements and frost formation can be alleviated.

Abstract: The present application relates to a bladed stator of a turbomachine compressor, configured to straighten an annular stream of the turbomachine. The stator includes at least one annular wall configured to define the annular stream, a row of blades extending radially from the annular wall and means of pressurizing in communication with the annular stream. The means of pressurizing are configured to pressurize a chamber which is separated from a lubrication housing by a labyrinth seal. The means of pressurizing comprise at least one passage extending through the thickness of the annular wall and connecting with the annular stream. The means of pressurizing further includes at least one scoop in communication with the passage and the annular stream. The scoop is open upstream so as to capture the dynamic pressure of the annular stream.

Abstract: Aspects of the disclosure are directed to controlling a distribution of fuel to a plurality of nozzles associated with at least one aircraft engine by: determining a state of operation associated with the at least one aircraft engine, causing a valve coupled to a fuel supply and each of the nozzles to open when it is determined that the state of operation indicates a high power state relative to at least one threshold, and causing the valve to close when it is determined that the state of operation indicates a low power state relative to the at least one threshold.

Abstract: A constant volume combustion chamber, combustor, and method for constant volume combustion involve combusting a fuel in a chamber sealed by a pintle having a conical portion fitted into a conical nozzle throat and pulling the pintle away from the nozzle throat to allow combustion products to exhaust through a nozzle outlet. The shapes and surfaces of the pintle and nozzle throat provide for sealing the chamber at high pressures while resisting surface wear. Operational parameters for the combustor may be computer controlled in response to measured pressures and temperatures in the combustor.

Abstract: A gas turbine engine and a method of operating the gas turbine engine according to an exemplary aspect of the present disclosure includes modulating a variable high pressure turbine inlet guide vane of a high pressure spool to performance match a first stage fan section of a low pressure spool and an intermediate stage fan section of an intermediate spool to maintain a generally constant engine inlet flow while varying engine thrust.

Abstract: A propulsion system including: a booster; a turbojet engine; the booster including a chamber which is fixed to a rear casing of the turbojet engine by being arranged along the longitudinal axis thereof, which chamber includes at a rear a jet pipe and includes at least one charge and a mechanism initiating the charge; and gas bleed tubes connected to the booster and which are configured either for igniting the combustion chamber of the turbojet engine on for starting the turbine of the turbojet.

Abstract: A pneumatic system 131 for use with gas turbine engines 10 and aircraft 100. The pneumatic system 131 comprises a first engine core compressor bleed offtake in the form of an engine handling bleed offtake 140, and a second engine core compressor bleed offtake in the form of first and second cabin bleed offtake 132, 134, the handling bleed being configured to supply higher pressure air than the cabin offtakes 132, 134. The system 131 comprises a turbocompressor 144 comprising an air compressor 148 driven by a turbine 146. The handling bleed offtake 140 is in fluid communication with the turbocompressor air turbine 146 to thereby drive the air turbine 146, and the cabin bleed offtakes 132, 134 are in fluid communication with the turbocompressor air compressor 148 such that air from the offtakes 132, 134 is compressed by the turbocompressor air compressor 148.

Abstract: A nozzle is provided that is capable providing flowpaths for a combined cycle aircraft propulsion system that in one form includes a gas turbine engine and a ramjet. The gas turbine engine produces an exhaust flow that is offset from an exhaust flow from the ramjet. The two streams can be flowed independent of each other or together depending on the application and relevant portion of a flight envelope. The nozzle includes a movable portion that can selectively open and close an exhaust flowpath for the gas turbine engine. The nozzle includes a surface that provides expansion for both low speed (gas turbine engine) flow and high speed (ramjet) flow.

Abstract: The present disclosure relates to an engine having two modes of operation—air breathing and rocket—that may be used in aerospace applications such as in an aircraft, flying machine, or aerospace vehicle. The engine's efficiency can be maximized by using a precooler arrangement to cool intake air in air breathing mode using cold fuel used for the rocket mode. By introducing the precooler and certain other engine cycle components, and arranging and operating them as described, problems such as those associated with higher fuel and weight requirements and frost formation can be alleviated.

Abstract: A gas generator for a reverse core engine propulsion system has a variable cycle intake for the gas generator, which variable cycle intake includes a duct system. The duct system is configured for being selectively disposed in a first position and a second position, wherein free stream air is fed to the gas generator when in the first position, and fan stream air is fed to the gas generator when in the second position.

Abstract: This invention relates to an engine (2) for use in aerial vehicle (1) including a rocket (9) and ram jet engine formed from an intake (8) and a combustion chamber (10). The rocket engine (9) includes an oxidiser combustion chamber (21) which exhausts through the combustion chamber (10). The engine also includes a nozzle (12). Both the intake (8) and nozzle (12) include rectilinear ducts which are defined in part by baffles (16) and panels (33) respectively. Both the baffles (16) and panels (33) are adjustable to adjust the airflow characteristics therethrough.

Abstract: A method is provided for fuel injection in a sequential combustion system comprising a first combustion chamber and downstream thereof a second combustion chamber, in between which at least one vortex generator is located, as well as a premixing chamber having a longitudinal axis downstream of the vortex generator, and a fuel lance having a vertical portion and a horizontal portion, being located within said premixing chamber. The fuel injected is an MBtu-fuel. In said premixing chamber the fuel and a gas contained in an oxidizing stream coming from the first combustion chamber are premixed to a combustible mixture. The fuel is injected in such a way that the residence time of the fuel in the premixing chamber is reduced in comparison with a radial injection of the fuel from the horizontal portion of the fuel lance.

Abstract: An apparatus for igniting a larger rocket motor is provided. The apparatus may be a smaller rocket motor that can be ignited hypergolically, when a pressurized oxidizer contacts hypergolic fuel grains of the smaller rocket motor. The hypergolic ignition causes the larger rocket motor to be ignited. The hypergolic ignition of the smaller rocket motor may be stopped after the larger rocket motor is ignited, and the remaining hypergolic fuel grains and the pressurized oxidizer can be reserved for reigniting the larger rocket motor at a later time.

Abstract: In an SEV combustor and a method for reducing emissions in an SEV combustor of a sequential combustion gas turbine, an air/fuel mixture is combusted in a first burner and the hot gases are subsequently introduced into the SEV combustor (1) for further combustion. The SEV combustor (1) includes a chamber having a chamber wall (5) defining a mixing portion (8), for mixing the hot gases with a fuel, and a combustion region (9), at least one inlet (2) for introducing the hot gases into the mixing region (8), at least one inlet (12) for introducing a fuel into the mixing region (8) and at least one inlet (10, 13) for introducing steam into the mixing region.

Abstract: The present invention relates to a mechanical system and method that modulates airflow in an aircraft inlet diffuser that is used in conjunction with an aircraft engine that integrates both a center turbine engine and a high Mach engine such as a constant volume combustor (CVC) arrangement or ramjet arrangement with intakes formed co-centrically about the turbine. The modulation system uses two articulating components, a movable air flow duct and an articulating cone. The air flow duct, in a first position, is in exclusive air flow communication with the circular intake face of the turbine in a first position to receive air from the intake diffuser. In this configuration the expandable cone is in a retracted position and does not redirect airflow and allows the aircraft to operates in low speed mode as only the turbo jet receives airflow. In a transition speed mode, the air flow duct is retracted to allow air flow to both the turbo jet and the CVC.

Abstract: A device for cooling hot gas to be discharged from an aircraft includes a duct for leading the hot gas from a hot gas source which is connectable to the device to an outlet point, and a frame which surrounds the duct and serves for mounting the duct. The duct is formed from one or more pipe sections and has one or more cooling air inlet points which is connectable to one or more cooling air sources in order to mix the hot gas with cooling air. An outlet pipe section of the duct extends outwards beyond the aircraft outer skin to lead hot gas through and out of a flow boundary layer on the outer skin.

Abstract: A propulsion system for a combined aircraft/spacecraft including: a jet engine having a longitudinal axis defined in a direction from a front end at an air intake to a rear end at a jet exhaust: a front end at an air intake to a rear end at the jet exhaust; a rocket engine having a longitudinal axis defined normal to a rear end at a rocket exhaust; a common engine housing having an elongated shape and wherein the jet engine and the rocket engine are configured substantially coaxially and with respective rear ends facing the same direction when the rocket engine is operated.

Abstract: There is disclosed a vehicle and methods for maneuvering the vehicle. The vehicle may include a plurality of multiple-impulse rocket motors, each of which comprises a plurality of independently ignitable solid fuel propellant charges, and a processor that generates at least one command to ignite at least one solid fuel propellant charge of at least one of the plurality of multiple-impulse rocket motors.

Abstract: A core engine of a variable cycle gas turbine engine includes a low pressure spool for generating streams of bypass air and pressurized air, and a high pressure spool for further pressurizing the stream of pressurized air to generate streams of combustion air and supercharged auxiliary air. A peripheral case surrounds the engine case to form a peripheral duct. An auxiliary combustor and propulsor are positioned within the peripheral duct. A bleed duct extends from the high pressure spool to the auxiliary combustor. Variable ductwork directs airflow through the bleed duct and peripheral duct in two modes. A first mode comprises directing the stream of auxiliary air to the auxiliary combustor, and directing stream of inlet air through the peripheral duct. A second mode comprises directing the stream of auxiliary air into the stream of bypass air, and preventing inlet air from entering the peripheral duct.

Abstract: An insensitive combined cycle missile propulsion system includes a solid fuel contained within a first section of the missile, a liquid oxidizer contained within a second section of the missile and a solid oxidizer contained within a third section of said missile. A first conduit has a first valve communicating the fuel and the oxidizer and a second conduit, spatially removed from the first conduit, has a second valve communicating the fuel and the oxidizer. An inlet system for delivering atmospheric oxygen for combustion with the fuel rich gases generated within the missile and a nozzle exhausts combustion products that result from combustion of the fuel, the liquid and solid oxidizers, and air.

Abstract: An engine combination for generating forces with a gas turbine engine generating force, and an internal combustion engine provided in the combination as an intermittent combustion engine generating force having an air intake, there being a plurality of air transfer ducts each extending from a different location in the gas turbine engine so as to be capable to provide air in each of those air transfer ducts at one end thereof at pressures differing from one another and connected at the other end of each to the air intake to transfer air thereto.

Abstract: Multiple-use rocket engines and associated systems and methods are disclosed. A method in accordance with a particular embodiment includes launching a two-stage vehicle have a first stage and a second stage carried by the first stage. The first stage can be powered with a first rocket engine having first rocket engine components, including a first combustion chamber, arranged in a first component configuration. The method can further include separating the second stage from the first stage, and powering the second stage with a second rocket engine having second engine components arranged in a second component configuration. The second rocket engine components can include a second combustion chamber that is interchangeable with the first combustion chamber. In further particular embodiments, recovered engine components from the first stage may be used to power the second stage of the same or a different two-stage vehicle.

Abstract: The present invention relates to a propulsion system for a vehicle. The propulsion system has an airframe integrated hydrocarbon fueled airbreathing engine, such as a ramjet or a scramjet. The propulsion system further has at least one rocket positioned so as to use the aft body contour of the vehicle directly for flow expansion. In a preferred embodiment, a plurality of rockets are arrayed across the width of the engine nozzle.

Abstract: An engine combination for generating forces with a gas turbine engine generating force that utilizes an engine lubricant for lubricating moving components in the turbofan engine, and an internal combustion engine provided in the combination as an intermittent combustion engine generating force that utilizes a coolant for transporting heat generated in the intermittent combustion engine away therefrom and having an air intake, there being an air transfer duct connected from a compressor in the gas turbine engine to the air intake to transfer compressed air thereto. A coupling heat exchanger is coupled to both the gas turbine engine and the intermittent combustion engine to have the engine lubricant and the coolant pass therethrough. A further cooling heat exchanger is coupled to both the coupling heat exchanger and the intermittent combustion engine to have a remote fluid from a source thereof and the coolant pass therethrough.

Abstract: Hypersonic aircraft having a lateral arrangement of turbojet and SCRAMjet engines are disclosed. The SCRAMjet engines may be positioned laterally outboard of the turbojet engines. In one embodiment, the turbojet inlet and outlet openings may be covered during use of the SCRAMjets in order to provide compression and expansion ramps for the laterally adjacent SCRAMjet engines. The side-by-side arrangement of the turbojet and SCRAMjet engines reduces the vertical thickness of the aircraft, thereby reducing drag and potentially increasing performance.

Abstract: A gas turbine engine with a turbine with an exhaust manifold thereabout from which fluids can be transferred to the turbine and an air compressor having an air transfer duct extending therefrom so as to be capable to provide compressed air in that air transfer duct at one end thereof to the air intake of an internal combustion engine provided as an intermittent combustion engine. The air intake and an exhaust outlet are each coupled to combustion chambers therein and a rotatable output shaft is also coupled to those combustion chambers for generating force. The exhaust outlet has an exhaust transfer duct extending therefrom so as to have the intermittent combustion engine be capable to provide exhaust therefrom in that exhaust transfer duct at one end thereof, and the exhaust transfer duct being connected at an opposite end thereof to the exhaust manifold to be capable of transferring intermittent combustion engine exhaust thereto.

Abstract: An engine combination for generating forces with a gas turbine engine generating force, and an internal combustion engine provided in the combination as an intermittent combustion engine generating force having an air intake, there being an air transfer duct connected from a compressor in the gas turbine engine to the air intake to transfer compressed air thereto.

Abstract: A power generation system for propelling, and generating electrical power in, an aircraft, having a gas turbine engine in an engine compartment in the aircraft with an air inlet in the aircraft that is curved along its extent in leading to an air compressor in the gas turbine engine having a compressor air transfer duct extending therefrom to an internal combustion engine provided as an intermittent combustion engine at an air intake thereof. An inlet duct manifold is positioned against the duct wall of the inlet duct to cover a perforated portion thereof on the air compressor side of a curve therein with the inlet duct manifold having an inlet air transfer duct extending therefrom that is coupled to the intermittent combustion engine air intake.

Abstract: An engine system comprises a first transfer positive displacement, volumetric device, at least one second positive displacement, volumetric device, and a transmission in engagement with two adjacent volumetric devices. The transmission has a ratio designed to cause the at least one second volumetric device to rotate at a higher angular velocity than the first volumetric device, inducing expansion of a compressible fluid during continuous flow from the first volumetric device to the at least one second volumetric device while performing work.

Abstract: A propulsion system for a combined aircraft/spacecraft including: a jet engine having a longitudinal axis defined in a direction from a front end at an air intake to a rear end at a jet exhaust: a front end at an air intake to a rear end at the jet exhaust; a rocket engine having a longitudinal axis defined normal to a rear end at a rocket exhaust; a common engine housing having an elongated shape and wherein the jet engine and the rocket engine are configured substantially coaxially and with respective rear ends facing the same direction when the rocket engine is operated.

Abstract: A propulsion system with a pintle for variable thrust is constructed such that the pintle contains a shaft at its fore end which passes through an opening in the thrust chamber wall and extends into a boss on the outside surface of the thrust chamber. A dynamic seal that maintains the pressurization of the thrust chamber while allowing movement of the pintle is positioned inside the boss, between the pintle shaft and the boss, and actuation of the pintle is achieved by a rack affixed to the fore end of the pintle and a gear that engages the rack. The dynamic seal, rack and gear are thus external to the thrust chamber, providing the thrust chamber with a compact external envelope, a greater thermal standoff, or both.

Abstract: An air inlet duct for an air-breathing combined-cycle aircraft engines is internally divided into separate channels for low-speed and high-speed components of the engine, and contains one or more movable panels that are fully contained within the duct and pivotal between an open position in which incoming air is directed to both channels and a closed position in which all incoming air is directed to the channel leading to the high-speed engine. This integrated duct utilizes all incoming air at all stages of flight with no change in either the geometry of the air capture portion of the engine or the engine itself, and no exposure of movable leading edges. The result is a minimum of shock waves and a high degree of efficiency in operation of the engine.