Abstract: An air vehicle landing/takeoff area mapping system includes a plurality of transmitters located in the landing/takeoff area with each transmitter propagating a signal having a signal frequency indicative of the transmitter location. A receiver is located on the air vehicle and is capable of scanning the landing/takeoff area. The receiver processes a received transmitter signal to produce an output based on the received transmitter signal frequency. Control logic processes a sequence of receiver outputs to produce an image of the landing/takeoff area on a display device located within the air vehicle to assist a pilot during landings and takeoffs of the air vehicle under either clear or inclement weather conditions and/or either day time or night time visibility.

Abstract: A method and system for controlling a dynamic nonlinear plant. An input signal controls the plant and an output signal represents a state of the plant in response to the received input signal. A memory stores input and output signals corresponding to m consecutive past states of the plant. A computer neural network predicts a set of future output states representative of the output signal corresponding to the next n consecutive future states of the plant in response to a set of trial control inputs. The trial control inputs represent the input signal corresponding to the next n consecutive future states of the plant. The neural network predicts the future output states based on the past input and output signals and the future trial control inputs. A processor generates the trial control inputs and determines a performance index, indicative of plant performance over time in response to the trial control inputs, as a function of the future output states.

Abstract: A system for monitoring the concentration level of a gas in a monitored environment, e.g., for monitoring the concentration level of a fire suppression agent in the engine bay and/or cargo bay of an aircraft. The system includes a light source for producing source light, an optical system that directs the source light along a plurality of different optical paths having different respective optical path lengths, and a plurality of photodectors that are positioned to receive the source light that traverses different respective ones of the plurality of different optical path lengths, and which produce a plurality of output signals indicative of the concentration level of the gas in the monitored environment. In the preferred embodiment, the system further includes a narrow band spectral filter positioned between the light source and each photodetector, wherein the narrow band spectral filter has a narrow band pass that is matched to a selected optical absorption wavelength of the gas.

Abstract: A new approach for software debugging, verification and validation is disclosed. The present invention utilizes a knowledge-based reasoning approach to build a functional model of the software code for identifying and isolating failures in the software code. The knowledge-based reasoning approach of the present invention uses the software design, which is preferably based upon a flow chart or block diagram representation of the software functionality, to build the functional model. The software block diagram contributes to the functional model by defining the inputs and outputs of the various blocks of code, as well as defining data interconnections between the various blocks of code. In accordance with a method of the present invention, test points are strategically inserted throughout the code, and each test point is associated with a corresponding block of code. Expected values of the test points for an expected proper-operation execution of the computer program are generated.

Abstract: The present invention comprises an apparatus for locking the pitch axes of the rotor blades of a rotor/wing aircraft so as to form a rigid wing. In one embodiment of the present invention the rotor blades of a rotor/wing aircraft are locked to each other to form a rigid wing assembly having a common pitch axis. This wing assembly is then locked in position about its pitch axis by means of a pitch lock apparatus that engages the lower end of the pitch link of the rotor blade that is oriented at the leading edge of the fixed wing. In another embodiment each rotor is independently locked about its respective pitch axis by means of two separate pitch lock apparatus. By locking the rotor blades into a rigid assembly by means of an independent rigid pitch lock apparatus, it is possible to provide a rotor/wing aircraft having a fixed wing with more predictable and controllable response to aerodynamic forces.

Abstract: A fault-tolerant data processing system includes first and second microcircuits in a master/checker configuration. The first and second microcircuits perform identical transforming operations on identical data to generate respective outputs. The internal state of each microcircuit is encoded to a short code word and communicated to an external comparator. The comparator compares the encoded internal state data of the first and second microcircuits to determine if an error has occurred. Low error detection latency may be realized due to increased frequency of error detection, with minimal hardware and performance overhead.

Abstract: A hydraulic damper assembly has a barrel-piston assembly and a spring assembly. The barrel-piston assembly has a barrel with a top portion having an open end, and a piston extending through the open end. The piston has a bottom portion that is located inside the barrel. The piston and the barrel also define an annular space in which is a barrel shoulder and a piston shoulder. The barrel shoulder radially extends into the annular space from the barrel top portion. The piston shoulder radially extends into the annular space from the piston bottom portion. The spring assembly is disposed in the annular space between the barrel shoulder and the piston shoulder. When the piston is extended from the barrel, the shoulders compress the spring assembly and, thereby, reduce the amount of force required to compress the piston which enables the damper to be charged to a higher nitrogen pressure.

Abstract: A low-density, syntactic foam material is provided according to the invention. The syntactic foam material is prepared by mixing together a plurality of microballoons and a finely divided solid thermosetting resin. Fibers are also preferably incorporated into the material during processing to impart specific properties. The mixture is heated to allow the thermosetting resin to flow and wet the microballoons in the mixture. The mixture is then cured to set and crosslink the thermosetting resin to form the syntactic foam of the invention. The syntactic foam material has highly uniform properties and can be used in aerospace applications.

Abstract: A method for reducing material property degradation during friction stir welding. More specifically, the method includes the steps of solution heat treating first and second structural members at a first predetermined temperature schedule. The first and second structural members are then quenched to a predetermined temperature at which the structural members are in a nonequilibrium state and have an incomplete temper. The first structural member is then positioned adjacent to the second structural member, thereby defining an interface therebetween. Thereafter, the first and second structural members are joined to form a structural assembly by friction stir welding the material along the interface prior to precipitation heat treating the structural assembly. The structural assembly is then aged, such as by precipitation heat treating, at a second predetermined temperature schedule to stabilize the material properties of the resulting structural assembly, thereby completing the temper of the material.

Abstract: An apparatus and a method for aligning an optical fiber with an optoelectronic device inside an optoelectronic package using an internal automated micro-aligner and internal solder heater means for locking the optical fiber in a precisely aligned position with the optoelectronic device.

Abstract: The present invention comprises an apparatus for locking both rotor blades of a rotor/wing aircraft at a common point to form a rigid wing having a uniform bilateral aerodynamic response. In one embodiment of the present invention the rotor blades of a rotor/wing aircraft are locked together to form a rigid wing assembly. This is accomplished by locking the blades together by a locking mechanism that engages when the rotor speed drops below a certain threshold. With the rotor blades locked together, the wing assembly can then be locked in position with the appropriate pitch angle simply by securing the pitch link of the rotor blade that is oriented at the leading edge of the fixed wing. In another embodiment of the invention the blades are locked directly to the rotor by two locking mechanisms that engage the hub directly.

Abstract: The invention relates as a whole to composite structures and may be used, in particular, in the manufacture of bodies or compartments of flying vehicles used in rocketry and aeronautics.A composite shell shaped as a body of revolution comprises a load-bearing framework of a multilayer structure consisting of intersecting spiral and annular strips arranged at intervals and forming cross nodes and stiffening ribs therebetween, an outer load-bearing shell, fine-cellular layers consisting of spiral and annular strips therebetween, surrounding the stiffening ribs of the framework in the directions thereof, and having the width exceeding the width of the strips in the ribs and forming their bearing flanges. The spiral and annular strips of the framework and of the fine-cellular layers, and the outer load-bearing shell are made of unidirectional fibers and a polymer binder.

Abstract: A visual display system for producing a continuous far-focused virtual image according to the present invention includes a number of adjacent video image generation and display modules. Each module includes an image generator that generates a video image representative of a portion of a composite display image displayed on a video display. The visual display system also includes a number of optical viewing lenses associated with each video image generation and display modules and positioned between the operator and the video display. The lenses restrict the operator's field of view such that the operator views only a portion of the active display area of the video displays. The lenses of adjacent modules are joined together along their edges to form an enclosure partially surrounding the operator so that the operator views the composite display image displayed on the video displays through the lenses and perceives the composite display image as a continuous far-focused virtual image.

Abstract: The present invention is a method, system and apparatus for aiming an x-ray system at the surface of a target object, such that the x-ray beam will strike the surface of the target object at a predetermined angle and direction. A laser is positioned on the surface of the target object, such that the linear beam of light emitted from the laser forms an angle with respect to the surface of the target object corresponding to the predetermined angle and direction at which the x-ray beam is desired to strike the surface of the target object. A mirror is placed on the lens of the x-ray tube. The x-ray lens and the object are then configured such that the laser beam strikes the mirror and is reflected back to the point of origin. The x-ray device is thus aimed such that, when energized, the x-ray beam will strike the surface of the target object at the predetermined angle and direction.

Abstract: A precision grinding apparatus includes a grinding worm for precision grinding a case-hardened face gear. A shaper is first placed into contact with a face gear, to thereby shape a surface of the face gear into a plurality of face gear teeth. The shaper is then removed, and the face gear is case hardened. The grinding worm is disposed in a normal orientation to the case-hardened face gear and includes a spiral tooth extending along a perimeter of the grinding worm. The spiral tooth of the grinding worm is adapted to contact and precision grind the case-hardened gear. A dressing tool includes a protrusion for contacting the spiral tooth of the grinding worm, as the spiral tooth contacts and precision grinds the case-hardened face gear. The dressing tool thus maintains the shape of the grinding worm to within a desired tolerance range.

Abstract: A dispensing system for releasing a number of spacecraft from a launch vehicle. The dispensing system includes a base support structure securely fastened to a launch vehicle and a number of stacked frame assemblies. Each frame assembly includes a number of substantially parallel load bearing elongated post elements and a shear load transferring structure. The post elements are so arranged and spaced so as to define a geometry having a centerline. Each post element has a first end portion and a second end portion. Each first end portion is connected to either another frame assembly or the base support structure of the launch vehicle. The post elements support a number of spacecraft. The spacecraft are supported between adjacent post elements. The shear load transferring structure is connected to the post elements for transferring shear loads between the post elements.

Abstract: A method for producing a spatially stratified Optical System includes the steps of a) selecting a suitable, spatially stratified profile of index of refraction to achieve an optical system having a desired performance; b) selecting an atomic/molecular species having a suitable index of refraction in a desired operational wavelength band; c) forming sub-micron pellets of the species; and d) placing the pellets into a host material while controlling the density of the placement. The density is varied to achieve a local index of refraction value for the optical system in accordance with the selected stratified profile. The wavelength regime the optical system is designed for is much greater than the characteristic scale of stratification, which in turn is much greater than the spatial size of the pellets. The optical system is much greater than the wavelengths in the wavelength regime.

Abstract: An actively controlled helicopter rotor blade includes a trailing edge flap actuated by a fast-acting actuator. A lightweight, rugged, fast-acting actuator suitable for use as the flap actuator comprises a pair of column actuators composed of a smart material such as piezoelectric, magnetostrictive, shape memory alloy or other material that exhibits a shape change when subjected to an external stimulus. Each of the column actuators is composed of multiple piezoelectric ceramic actuator elements bonded together to form the individual columns. Each of the column actuators engages the base of an actuator tube that, in turn, is urged against the column actuators by a tension member. Differential voltage applied to the columns causes a differential elongation of the column actuators, which causes the actuator tube to pivot about an axis proximal the tips of the column actuators. The movement of the actuator tube is coupled by a linkage to the rotor blade flap.

Abstract: An articulating and telescoping duct is provided for use in a helicopter reaction drive flow path for ducting the exhaust and/or bypass gases from the aircraft engine into the flow ducts of the rotor blades. In a preferred embodiment the telescoping duct comprises a tubular member having a bead formed at each end. Each of the beads has an outside surface formed into a spherically curved sector that is centered radially about the axis of the tubular member. The receiving duct at one end comprises a complementary spherical bore that seals against and retains the spherical outside surface of the tubular member while permitting the tubular member to articulate relative to the receiving duct. The receiving duct at the other end comprises a complementary cylindrical bore that seals against the spherical outside surface of the tubular member while permitting the tubular member both to articulate relative to and telescope in and out of the cylindrical bore.

Abstract: An aircraft engine apparatus with a reduced inlet vortex is provided which utilizes a vortex disruption system that periodically discharges pulses of engine bleed fluid through at least one outlet port opening through the inlet of the engine nacelle to disrupt the engine inlet vortex. The vortex disruption system thereby prevents ingestion of foreign matter into the engine inlet without sacrificing engine power, efficiency, or aircraft cruise performance.