Abstract: A vehicle in free space or air, with external surfaces primarily fashioned from planar facets. The planar facets or panels are angularly positioned to reduce scattered energy in the direction of the receiver. In particular, radar signals which strike the vehicle are primarily reflected at an angle away from the search radar or are returned to the receiver with large variations of amplitude over small vehicle attitude changes.

Abstract: Gel coating of thermoplastic particles, such as polyimide particles, with a polyketone or polyvinyl alcohol gel, and applying the gel coated particles to reinforcement, e.g. carbon, fibers to form a pre-preg. Such gel coated thermoplastic particles can be mixed with a thermosetting resin to form a pre-preg, which can be cured at elevated temperatures to form a composite having damage tolerance characteristics. The gel coating is applied to the thermoplastic particles by contacting such particles with a polymerizable material such as acetone in a weakly acidic solution to cause the acetone to undergo tautomerism, and in the presence of a polymerization promoter or catalyst, preferably certain anionic surfactants such as sulfated ammonium salts, to convert the tautomer to polyacetone gel of low molecular weight, which coats or encapsulates the thermoplastic particles.

Abstract: A corrosion and crack growth inhibitor is disclosed, the inhibitor being relatively non-toxic as well as unreactive with curable elastomeric materials so as to form a coating composition for application to metal surfaces. The inhibitor comprises a curable polymer material, such as epoxy polyamide, and cerous molybdate in the amount of from about 1 to 15 percent by weight of the inhibitor.

Abstract: A method of making a structure having a plurality of serrations on a surface is provided wherein each serration is positioned at a specific location along the surface, has first and second sides with specific lengths, and has effectively zero radius internal and external corners. In detail, the method comprising the steps of: providing a plurality of sheets of material having opposed principal surfaces, each said sheet having a thickness equal to the specific thickness of one of the first sides of the serrations; stacking said plurality of sheets of material in a staggered relationship such that said thicknesses of said sheets of material are in an order corresponding to the order of the first sides of the serrations and the distance between the ends of the adjacent ends of said sheets of material are in an order corresponding to the second sides of the serrations; and joining said stacked plurality of sheets of material together forming a joined stack with at least one end having a serrated surface thereon.

Abstract: A non-toxic corrosion resistant conversion coating for aluminum is formed by a process which includes subjecting the aluminum to an acidic aqueous solution containing potassium permanganate and cerous chloride, alone or in combination with strontium chloride. The corrosion resistance is improved by a subsequent treatment in an alkaline solution containing molybdate, nitrite and metasilicate ions. The corrosion resistant is further improved by treating the coated surface with an alcoholic solution containing glycidoxy(epoxy)polyfunctionalmethoxysilane, alone or in combination with phenyltrimethoxysilane. The coating thus produced is a mixture of oxides and hydroxides of cerium strontium and aluminum. These oxides and hydroxides may also be intermixed with molybdate silicate and nitrite ions. In the most corrosion resistant form the mixture further includes a silane overcoat.

Abstract: The invention is a process for forming a hollow tubular member with an integral attachment end fitting.

Abstract: A penetrameter is provided for use in evaluating the resolution of an x-ray inspection system as well a method for calibrating the resolution of the x-ray inspection system. The penetrameter comprises a radiolucent substrate, and at least one filament at the radiolucent substrate, the at least one filament being broken by a gap having a predetermined size. The method of determining the resolution of an x-ray inspection system comprises steps of: generating a radiographic image of the penetrameter, determining if the broken filament is visible, and if the broken filament is visible, determining if the gap is visible.

Abstract: The invention is a propulsion system for a V/STOL type aircraft. In detail, the invention comprises a turbofan engine including a fan section, compressor section, combustion section, turbine section and nozzle section. The turbine section comprises a low-pressure turbine portion coupled to and driving the fan section and a high-pressure turbine portion coupled to and driving the compressor section. A lift fan is coupled to the fan section by means of a drive shaft. A clutch is incorporated for decoupling the lift fan from the fan section. A mechanism is incorporated for extracting additional power from the low-pressure turbine portion of the turbine section to drive the lift fan that augments the basic engine thrust for V/STOL operation.

Abstract: A computerized apparatus and method for drilling holes in elongated workpieces. Predetermined locations for holes are input into a computer by visually aligning hole locations on a template with the drilling axis of the apparatus. The computer controls movement of the drill and of the ring segment relative to the drill. The workpiece is moved relative to the drill and is stopped at each predetermined location for drilling.

Abstract: The antenna system includes a complementary "bowtie" dipole-slot antenna, the antenna having symmetrical halves about a plane of symmetry. The two halves of the antenna are slanted at the plane of symmetry such that the total included angle between the halves is between 70 degrees and 120 degrees. A ground plane is positioned between the halves of the antenna extending through the plane of symmetry. A circuit is included for independently exciting the halves of the antenna. In a second embodiment the ground plane incorporates a pair of notch antennas. Thus, both vertical and horizontal polarization can be achieved independent of each other.

Abstract: An ultrasonic calibration block for standardizing an output of a pulse-echo ultrasonic inspection system is provided with an insonification surface for receiving ultrasonic pulses from the inspection system and a plurality of reflective interfaces stacked on top of one another and positioned at different distances from the insonification surface, each reflective interface having a different and characteristic reflectivity. A method of calibrating the output of the inspection system, using the calibration block, employs standard waveforms generated by insonifying the calibration block to generate a look-up table of standard waveform amplitudes related to a standardized output of the inspection system for a given material of a part to be inspected.

Abstract: The invention is a pylon for supporting a model above a ground plane for radar cross-section testing using a radar providing a specific frequency range and power distribution above the ground plane. In detail, the pylon comprises a column made of a low dielectric constant foam material having a base end for mounting on the ground plane, a model mounting top end and a generally circular cross-section. The column has an abrupt change in diameter at a point between the ends forming a step and dividing the column into upper and lower tapered portions with each of the portions having a specific diameter range. The step is located at a point on the column such that the power is evenly split between the upper and lower portions and the specific diameter ranges of the portions are selected to maintain a 180-degree phase change in the return signal from each of the portions reducing the RCS of the pylon.

Abstract: Preparation of conductive polymers, particularly polyanilines having good solubility in organic solvents and high electrical conductivity, by providing a mixture of aniline, dianiline and a flexible diamine such as 1,3-bis (3-aminophenoxy)benzene or triethylene tetramine. The mixture is reacted in the presence of an oxidant such as ammonium persulfate and a protonic (Bronsted) acid, e.g. tosic acid, to polymerize the mixture and form a conductive polyaniline in which the conjugation is interrupted by an intermediate diamine group, and which renders the resulting polymer more flexible than polyaniline per se. The conductive polymer so produced also has terminal primary amino groups which aid solubility and which are further reactive. The conductive polyaniline product of the invention can be blended with non-conductive resins such as polyimides to provide cured conductive resin blends having good mechanical properties.

Abstract: A temperature compensated strain sensor for measuring the strain at specific locations within a molded composite structure and the like, is disclosed. In detail, the invention comprises a hollow tubular member mounted within the structure which has first and second ends extending out thereof and passing in proximity to each specific location at with strain is to be measured. A first optical fiber is mounted within the hollow tubular member and has first and second ends exiting the first and second ends, respectively, of the hollow tubular member. A plurality of second optical fibers, equal to the number of specific locations at which strain is to be measured, are mounted within the hollow tubular member and have first and second ends exiting the first and second ends, respectively, thereof. One each of the second optical fibers exits the hollow tubular member and extends across and is bonded to the resin of the structure at the specific location and thereafter re-enters the hollow tubular member.

Abstract: The invention is an apparatus for supporting a model above a ground plane for illumination by a radar signal in order to determine the RCS thereof. The apparatus includes a plurality of support towers in a spaced relationship extending vertically upward from the ground plane. An upper suspension system is provided that comprises a separate cable attached at one end to an individual tower and attachable at the opposite end to the model at a single point on the upper surface thereof so that the model can be simultaneously rotated about the yaw axis and pitch axis. A circular shaped track aligned with the direction of the radar signal is mounted below the ground plane having a center of the radius at the point that the cables of the upper suspension system attach to the model. A platform is movably mounted on the track and thus, moveable with a circular motion about the point that the cables attach to the model. The platform incorporates a drive system so that it can be positioned at any point along the track.

Abstract: The invention is an apparatus for removing a coating from a fiber optic cable. The apparatus includes a support member. A heating coil, having first and second ends, is mounted to the stand, with the first end of the coil adapted to receive the fiber optic cable within the interior thereof. A container is mounted within the coil, the container having first and second closed off ends in proximity to the first and second ends of the coil, respectively, the first end of the container having an aperture for receiving the fiber optic cable. A power controller is electrically coupled to the heating coil for controlling the temperature thereof. A vacuum system is inlcuded for removing fumes from within the container produced when a coating is pyrolized.

Abstract: The invention is a cooling system for electronic circuit modules such as a printed circuit boards. In detail the invention comprises a housing assembly having first and second opposed plates. The opposed plates include a plurality of spaced guide rails thereon. A plurality of electronic modules each having a metallic frame, are slidably mounted in the opposed guide rails and detachably clampable thereto. A cooling system is included, which comprises: each of the guide rails having internal cooling passages, preferably in a serpentine pattern, with the cooling passages extending from the first and second ends of the rails; and each of the opposed plates having a coolant inlet passage and a coolant outlet passage coupling each end in parallel. A coolant flow control system is provided which insures that phase change cooling is accomplished within the serpentine shaped guide rails.

Abstract: An apparatus for consolidating sheets (13) of continuous graphite fiber in a thermoplastic matrix resin uses a roller (10) in conjunction with a heating surface (16) and a vacuum bag (12). A tack-welded stack of composite sheets (13) or prepreg is assembled onto a frame support structure (27) and placed into the vacuum bag (12) as an assembly (28) which is placed on a heated surface (16) whereby its temperature is elevated above the melting point of the matrix resin in the composite sheets (13). The roller (10) rolls over the bag (12) with the sheets (13) therein whereby any remaining air and gas between the sheets (13) is forced out ahead of the roller (10). After the roller (10) has passed, atmospheric pressure on the vacuum bag (12) is sufficient to prevent spontaneous delamination of the hot laminated panel formed by the sheets (13). The assembly (28) may then be moved to a cooling table (26) to complete the laminate consolidation process.

Abstract: The invention is a device for dispensing melted resin on a surface. In detail, the invention includes a housing having an inlet and an outlet passages and a guide passage therebetween. The inlet passage is adapted to receive a solid resin rod and the outlet passage includes a nozzle for dispensing the melted resin to the surface. Also included is a mechanism to sequentially move the rod from the inlet toward the outlet passage. Additionally, a heating coil is positioned about the outlet passage. An air transfer tube is provided having an inlet coupled to and a source of pressurized air and an outlet in proximity to the nozzle. The tube includes a first coil section mounted about the heating coil so that the pressurized air is heated prior to reaching the nozzle such that the surface is heated.