Abstract: Apparatus for uniformly blending and applying a mixture of a two part resin and radar absorbing fibers to a surface. The fibers retain their length distribution after mixing and application. The unreacted resin base and catalyst components of the resin, one or both of which are premixed with the fibers, are brought together in a dispenser which then conducts them to an in line motionless mixer element and from there to a nozzle which has an output orifice sufficient for the desired length of the fibers to retain the desired size distribution of the fibers in the applied resin. The apparatus is also capable of applying other types of fibers or other solid materials within the liquid polymer matrix with minimal breakage to the solid component.

Abstract: An elastomeric prepreg wherein a carrier, whether roving, yarn, broad goods or tape, is impregnated with an uncured elastomeric rubber system which may include the addition of modifiers to enhance the properties of the coating. The prepreg is capable of being spooled and de-spooled for subsequent filament winding or laid up into laminates. In either process no environmental control equipment is required as the volatiles have previously been removed, leaving the elastomer in the generally uncured state.

Abstract: An interceptor's point of impact on a targeted missile is quickly revealed in the milliseconds preceeding and following the impact by illuminating the target with radar signals at a high pulse repetition rate and observing the reflected radar echoes on an A-scope display. The position within the returned radar echo of a double echo and related changing phenomenon indicates the point of impact. Failing intercept, the miss distance is computed from the relative slant ranges to the targeted missile, the interceptor, and the double echo. The type warhead killed is revealed by a spectrograph slaved to the radar's antenna. Various techniques assist with the interpretation of the displayed patterns, including subtraction of previously stored patterns and display of the difference, display of characteristic patterns of various known missiles and interceptors stored in "look up" tables, and neural networks.

Abstract: A relatively impervious mechanical seal is formed between the outer surface of a tube and the inside surface of a mechanical fitting of a high pressure fluid or hydraulic system by applying a very thin soft metal layer onto the outer surface of the hard metal tube and/or inner surface of the hard metal fitting, prior to swaging the fitting onto the tube. The thickness of such thin metal layer is independent of the size of the tube and/or fittings. Many metals and alloys of those metals exhibit the requisite softness, including silver, gold, nickel, tin, platinum, indium, rhodium and cadmium. Suitably, the coating is about 0.0025 millimeters (0.10 mils) in thickness. After swaging, the tube and fitting combination exhibits very low leak rates on the order or 10.sup.-8 cubic centimeters per second or less as meaured using the Helium leak test.

Abstract: A metal substrate such as aluminum or an alloy thereof having an ultraviolet sensitive thermal control coating on the substrate such as an anodic coating or a white thermal control paint coating, and an ultraviolet degradation protective coating on the thermal control coating. The ultraviolet degradation protective coating can be an ultraviolet absorber such as quartz or an ultraviolet reflector such as aluminum oxide.

Abstract: A perforated sheet is diffusion bonded to a thin solid sheet. Each of the perforations of the perforated sheet is tapered, having a maximum diameter at the surface that is not bonded to the thin sheet and a smaller diameter at the surface that is bonded to the thin sheet. The bonded perforated sheet and thin sheet are included with other solid metallic sheets in a forming pack to be superplastically deformed into a structure. The bonded perforated sheet and thin sheet are placed on the top of the forming pack so that the thin sheet will face outwards after the structure is formed. After the superplastic deformation process is completed, the thin sheet is removed by machining to expose the perforated sheet and provide a structure for controlling laminar flow over the perforated sheet. The exposed surface of the perforated sheet includes the smaller diameter of each tapered perforation, while the inner-facing or blind surface of the sheet includes the maximum diameter.

Abstract: A hollow core fan blade for a gas turbine engine, having a continuous leading edge, is fabricated using a four-sheet superplastic forming/diffusion bonding process which results in a cost-efficient and lightweight, yet strong, structure. The rotor blade is comprised of a face sheet which has a 180 degree bend therein so that the two face sheet ends are aligned. Bonded to opposing sides of the face sheet are first and second core sheets, between which is the hollow core. To fabricate the blade, a core sheet assembly is inserted inside the prepared face sheet, thereby forming a Ti-Pack (titanium pack) assembly having a plurality of pressure-tight cells. The Ti-Pack is inserted into a cavity within a die, after which the rotor blade, having predetermined design characteristics, is superplastically formed by heating the die and selectively pressurizing the plurality of cells.

Abstract: A tiltwing aircraft, capable of in-flight conversion between a hover and forward cruise mode, employs a counter-rotating proprotor arrangement which permits a significantly increased cruise efficiency without sacrificing either the size of the conversion envelope or the wing efficiency. A benefit in hover is also provided because of the lower effective disk loading for the counter-rotating proprotor, as opposed to a single rotation proprotor of the same diameter. At least one proprotor is provided on each wing section, preferably mounted on the wingtip, with each proprotor having two counter-rotating blade rows. Each blade row has a plurality of blades which are relatively stiff-in-plane and are mounted such that cyclic pitch adjustments may be made for hover control during flight.

Abstract: A method for fabricating fiber reinforced resin matrix composite structures having molded outside surfaces with intermittent molded inside surfaces (e.g. an aircraft skin with internal stiffeners) is performed as follows: composite prepreg stiffener sections are preformed and laid up on the inside portion of the rigid portion of the vacuum bag and the lay-up debulked. Elastomeric tubes are then installed in rigid cavity portions of a hybrid vacuum bag and sealing wedges are forced into place to hold the elastomeric tubes and at the same time seal them to the rigid portion of the cavity. The elastomeric tubes extend through and protrude from the sealing wedges. Skin plies are then laid up on a primary mold and the hybrid bag installed on the mold. Index pins are provided to properly orient the hybrid bag to the primary mold or tool. A vacuum is then drawn on the bag, any vacuum leaks are remedied, and the part is ready for curing in either an oven or an autoclave.

Abstract: A hybrid resistance card (R-Card) is manufactured using a two-step process wherein an electrically conductive ink layer and an electrically resistive ink layer are printed onto a surface, which may be either a substrate or the part on which the R-Card is to be used. The conductive ink layer is selectively applied in a pattern of shapes to electrically short out portions of the resistive ink layer, thereby permitting the R-Card to have a predetermined resistive taper across its width according to a desired resistivity curve. The resistive ink layer comprises grid-like lines bordering and separating the conductive shapes. The resistive taper is substantially continuous along the length of the R-Card, at least linearly, though if the card is designed to cover an entire part, it is substantially continuous along a plurality of directions on the card, with the tapers being designed to round into one another.

Abstract: A bag-rack mounted on an aircraft ceiling has a handrail secured to a recessed lower front portion thereof by a mount which also spaces the handrail from the bag-rack. The handrail is dimensionally shaped to conform to the inner surface contours of a user's hand and the recessed portion is curved to accommodate the back of the user's hand when reach into the recessed area to grip the handrail. The handrail also has an electroluminescent panel light mounted in a channel therein. The channel and light are positioned so that the light illuminates the recessed portion of the bag-rack and back-illuminates the handrail. The back-illumination of the handrail and the color contrast between the bag-rack and handrail provide visual differentiation between the handrail and bag-rack as well as other nearby structures enabling the user to more easily discern the handrail from other vehicle structures.

Abstract: Contoured sandwich radomes and other composite structures having a core consisting of a series of flexible foam mandrels laid side-by-side, with inner and outer facings made up of a fabric impregnated with a resin system, capable of providing superior breakdown voltage characteristics when cured in one stage. Such structures are obtained by a process comprising laying a plurality of first plies of resin impregnated fabric in a contoured mold to form an outer facing, providing a plurality of narrow straight but flexible mandrels of plastic foam, laving individual groups of such foam mandrels in side-by-side relation onto the outer facing, one series of the foam mandrel groups positioned in a substantially transverse direction in the mold and another series of the foam mandrel groups positioned in a substantially longitudinal direction in the mold. The inner ends of the mandrel groups abut the sides of adjacent mandrel groups, to form a foam core.

Abstract: An aft facing step situated across the span of an airfoil. A chemical or thermal deicing or running wet anti-icing device is located in or on the airfoil upstream of the step, and causes water to run back towards the step. The step suddenly reduces the thickness of the airfoil chord section, which causes a disturbance in the boundary layer across the span of the airfoil downstream of the step. The aforementioned disturbance causes runback water to form droplets and be blown clear of the airfoil surface downstream of the step, thereby preventing ice from being formed on the airfoil surface downstream of the step.

Abstract: An apparatus for controlling the motion of a structural member on a space platform truss structure, launch vehicle, automobile, building, or the like is comprised of a first driving piezoelectric element and a second constraining piezoelectric element. The first piezoelectric element is embedded in or bonded onto the structural member. The second piezoelectric element is bonded onto the structural member, with a viscoelastic material (VEM) layer sandwiched between the structural member and the second piezoelectric element. The first and second piezoelectric elements are electrically connected in opposite phase. When the structural member is deformed by an applied force, the first driving piezoelectric element is correspondingly deformed, generating an electrical field. The electrical field is then applied in an opposite sense to the second piezoelectric element through the electrical connections, thereby oppositely deforming the second piezoelectric element with respect to the first piezoelectric element.

Abstract: A dual polarization antenna for use on an aircraft, preferably a helicopter or the like, permits practical and reliable high frequency radio communications in a severe non line of sight, nap of the earth flight environment. The antenna comprises both a horizontally polarized component and a vertically polarized component. The horizontally and vertically polarized components are formed of an integral element, which has a bend therein so that the two components have an angular orientation with respect to one another. The horizontally polarized component is oriented in a generally horizontal direction and the vertically polarized component is oriented in a generally vertical direction. Ideally, the horizontally and vertically polarized components are oriented as orthogonally to one another as possible, depending upon the airframe application.

Abstract: A forming die which includes a die cavity contains a forming blank composed of a metallic alloy having superplastic properties. The forming pressure in a pressurized space adjacent the forming blank is regulated by a pressure regulator. The volume of the die cavity is determined, as is the mass of gas initially contained in the die cavity at the beginning of the forming cycle. The total forming time is empirically determined. The average gas mass flow rate that will be exhausted from the die cavity is calculated by dividing the total mass of gas initially contained in the die cavity by the total forming time. A gas mass flow meter fluidly communicates with the die cavity and measures the mass flow rate of the gas displaced by the forming blank and exhausted from the die cavity. The gas mass flow meter is continuously monitored during the forming cycle or a gas mass flow rate signal is fed back to the pressure regulator.

Abstract: Two arms rotatably mounted in slideable abutment with an interior wall of a nozzle. The arms extend from a common axis of rotation, and each includes a bump having a crest running radially from the axis of rotation to the tip of the arm. Together with the opposing ceiling and adjacent sidewalls of the nozzle, the arms define the moveable throat of the nozzle. The ceiling of the nozzle opposite the arms is contoured so that rotation of the arms changes the area of the nozzle throat while changing the direction of fluid medium flowing through the nozzle. The arms are connected by a linkage which coordinates their movement. Coordinated rotation of the arms can simultaneously change the throat area of the nozzle and the direction of fluid flow, or change either the throat area or the direction of fluid flow while keeping the other constant.

Abstract: A process for forming single piece metal alloy panel structures includes both superplastic forming and braze bonding steps, and is particularly adapted to superplastically formable materials which are not particularly diffusion bondable, such as aluminum alloys. The process involves constructing a worksheet assembly from a plurality of worksheets which are associated with a brazing alloy capable of brazing the worksheets. At least two of the worksheets are joined in facing contact with each other by welding in a preselected pattern. The perimeter of the joined worksheets is then sealed, with the provision of means for permitting the admission of pressurized gas therebetween, after which the worksheet assembly is placed in a forming die. The actual structure forming process begins by heating the die and its associated worksheet assembly to a temperature suitable for superplastic forming, and simultaneously applying gas pressure at the means for admission of pressurized gas.

Abstract: A closed loop fully self-contained actuation system for converting a mechanical input motion into a mechanical output motion, which actuates a device such as a flight control surface on an aircraft, comprises an input actuator including a first fluid pressurizing means responsive to the mechanical input motion, and an output actuator including a second fluid pressurizing means, as well as a flexible fluid line extending between the first and second fluid pressurizing means to provide fluid communication therebetween. The second fluid pressurizing means is responsive to fluid flow through the fluid line, thereby initialing the output motion. The system is advantageous because it requires no hydraulic pumps, no accumulators, no reservoirs, and no dynamic seals or mechanical joints, permitting great reliability. The actuation system may be easily folded in conjunction with the apparatus on which it is employed, for compact storage.