Abstract: Apparatus for bleeding electrical charge and methods for installing a ground stud in a composite structure. The apparatus includes a ground stud and a composite structure including a hole. In one embodiment the ground stud engages the hole in the composite structure in a transition fit. In another embodiment the ground stud is countersunk within the composite structure. Embodiments of the present methods include drilling a hole in the composite structure; inserting the ground stud into the hole such that the ground stud is in electrical contact with conductive fibers within the composite structure; securing the ground stud to the composite structure; and attaching a connective device to the ground stud such that the connective device is in electrical contact with the ground stud. In some embodiments the ground stud and the composite structure engage one another in a transition fit.

Abstract: An aircraft component includes a composite structure and a metallic circuit on a film. The film is co-cured with the composite structure. The metallic circuit is patterned to dissipate energy generated by lightning strikes on the composite structure. The metal circuit is also patterned to provide connectivity for multi-function apparatus.

Abstract: A lightning protection appliqué incorporates a plurality of conductive plies adhesively affixed to a composite surface, at least a first one of the plies providing conductive characteristics sufficient to divert electrical energy from a lightning strike and at least a second one of the plies comprising operational circuitry. A dielectric ply is fixed to the composite surface over and completely covering at least one metal surface feature between the plurality of conductive plies and the composite surface.

Abstract: A lightning strike protection system for protecting composite structures, an improved lightning strike appliqué (LSA) for such a lightning strike protection system, and a method of protecting composite structures, such as an aircraft fuselage. The LSA is electrically connected to adjacent conductive surfaces, e.g., by a fuzz button or a wire bond inserted in the bottom of the LSA. An adjacent conductive surface may be another LSA, a lightning diverter overlay, or a current return network. Charge, e.g., from a lightning strike to the LSA, flows to the conductive layer through the electrical connector.

Abstract: The present invention concerns a method of producing a lightning diverter for conducting a lightning-induced electrical current, which is to be placed on structures such as wings on wind turbines, aircraft components, radomes and the like with the purpose of lightning protection. The method comprises the steps of making a plurality of holes in a plate of an electrically conductive material, filling said holes at least partly with one or more electrically non-conductive materials, and then finally dividing the plate—preferably into strips. The lightning diverter obtained hereby consists of a layer of electrically non-conductive material with a plurality of isolated segments of electrically conductive material. The invention further relates to a diverter strip with isolated segments of concave shapes being advantageous because of the good connection between the segments and the non-conductive material.

Abstract: A mechanism to tap an electrical source which uses an aircraft (preferably a lighter than air balloon) tethered by a conductive line. The conductive line is extended/withdrawn by a winch motor to adjust the altitude of the aircraft. The conductive line is isolated from the ground and an electrical conductor is connected to the conductive line and to an electrical load. In this manner, static electricity generated in the atmosphere is gathered for use.

Abstract: A method and apparatus for lighting protection. In one advantageous embodiment a method forms a lighting protection system on a composite surface of an aircraft. A dielectric coating is formed on the composite surface in which the dielectric coating covers a metal feature exposed on the composite surface. A metal adhesion promoter is applied in a pattern on the dielectric coating and over additional areas of the composite surface, including a grounding feature to form a metal adhesion promoter layer. A metal coating is formed on the metal adhesion promoter layer to create a path from an area including the metal feature to the grounding feature.

Abstract: An exemplary embodiment provides a multi-layer circuit joining assembly material configured to repair multi-layer flex circuits deployed on or in a composite surface as a lightning protection system. The multi-layer circuit joining assembly material includes a first conductive layer having a first end portion, a second conductive layer having a second end portion, and a dielectric material between the first conductive layer and the second conductive layer.

Abstract: A fastening assembly for a composite structure including a washer sealing the assembly for internal lightning strike protection. The washer includes one or more concentric ribs that are dielectric rings on both sides. When used (e.g., with a nut and bolt) internal to a structure, especially a composite structure, the washer seals the fastener hole (i.e., that the bolt passes through) and contains any sparking and hot gasses that may arise in the fastener hole from entering the structure.

Abstract: Unsafe electric energies can exist in aircraft fuel tanks as a result of static build-up or induced currents from lightning strikes. The invention provides an aircraft having a ground circuit 19 and including a fuel tank having a fuel probe circuit having its own ground circuit. Multiple discharge paths allow the safe discharge of electricity from the tank before it reaches levels where an arc, spark or other electric discharge, able to ignite fuel in the tank, could occur. The discharge paths all pass via a conductive foam having a relatively high impedance that allow static bleed, but does not significantly increase the risk of currents induced by lightning reaching levels at which an ignition-causing electrical discharge might occur. The foam is securely bonded to both the aircraft ground circuit and the fuel probe ground, the bonds having a large area of surface-to-surface contact.

Abstract: The invention relates to a device (1) for the protection against electrical discharges of a conductive fixing element (4) of an aircraft, comprising a cap (2) made of non-conductive material and a washer (3) made of non-conductive material insulating the fixing element (4) from electrical discharges, said cap being an open receptacle with a cylindrical shape closed at one of its ends and open at the other end, comprising at the lower part of its inner face a thread (15), the washer (3) being retained by the fixing element (4), said washer (3) having a thread (5) on its outer face coupling with the complementary thread (15) in the lower area of the inner face of the cap (2), relative movements between the washer (3) and the cap (2) being prevented.

Abstract: A washer, a fastening assembly including the washer and a composite structure including the washer sealing the assembly for internal lightning strike protection. The washer includes one or more concentric ribs that are dielectric rings on both sides. When used (e.g., with a nut and bolt) internal to a structure, especially a composite structure, the washer seals the fastener hole (i.e., that the bolt passes through) and contains any sparking and hot gasses that may arise in the fastener hole from entering the structure.

Abstract: There is provided a fastener able to prevent damage due to environmental factors such as ultraviolet rays, and impact from sanddust, lumps of ice, and raindrops without obstructing a flow of electric shock current that flows along a top surface of an outer skin. The fastener connects an outer skin of an aircraft to a structural member positioned inside this outer skin, and is provided with a dielectric layer arranged to cover one end surface of a head section, and a conductive layer arranged to cover one end surface of this dielectric layer.

Abstract: A system for lightning-protection of an aircraft skin panel that includes a nonconductive skin panel substrate and a series of spaced apart electrically conductive strips embedded in and extending along an outer surface of the nonconductive skin panel substrate. A series of electrically conductive fasteners extend through the nonconductive skin panel substrate to affix it to the airframe of the aircraft. The fasteners are arrayed along peripheral regions of the nonconductive skin panel substrate. Each of the electrically conductive strips is in electrical communication with the aircraft airframe through at least one fastener located proximate each end region of each strip.

Abstract: A lightning strike protection system for protecting composite structures, an improved lightning strike appliqué (LSA) for such a lightning strike protection system, and a method of protecting composite structures, such as an aircraft fuselage. The LSA is electromechanically connected to adjacent conductive surfaces, e.g., by a fuzz button or a wire bond inserted in the bottom of the LSA. An adjacent conductive surface may be another LSA, a lightning diverter overlay, or a current return network. Charge, e.g., from a lightning strike to the LSA, flows to the conductive layer through the electromechanical connector.

Abstract: The present disclosure provides a lightning protection system and a composite structure comprising such a lightning protection system, wherein the lightning protection system comprises a metal foil layer, a plastic layer, and a matrix material.

Abstract: An electrical insulation system for a linear element forming part of a fluid system subjected to risks of possible external electrical discharges, such as an aircraft fuel system, using an insulating insert (12) between two parts (14, 16) of said linear element, consisting of providing said parts (14, 16) with grooved edges and in forming the insulating insert (12) between them preferably by an injection technique, such that the insulating insert (12) provides an inner duct for the passage of fluid between said parts (14, 16) and covers said grooved edges, assuring the leak-tight joint of the insulating insert (12) with said parts (14, 16).

Abstract: This invention relates to a protection device against electrical discharges to an aircraft, especially against lightning, applicable to an external structural surface element (1), completely or partially built from a composite, comprising at least one metallic attachment element (7) with countersinking, a fine metallic mesh (2) for outer protection of said surface (1), a thick metallic mesh (5) in an area around the attachment elements (7); a metallic part (11) fixed to the inner face of the surfacing (1) by means of an attachment element (7); and a metallic washer (9) surrounding the countersunk area of the attachment element (7) with which said metallic meshes (2, 5) come into contact.

Abstract: The invention relates to a means for preventing build-up of electrostatic potential in a fluid container during filling and/or discharging. The fluid container comprises electrical insulating materials and a valve means through which filling and/or discharging occurs. Means for reducing and/or eliminating electrical and/or electrostatic potential build-up during filling or discharging of the container is arranged in conjunction with the container walls. Such means may for example be arranged in conjunction with the valve means, reducing and/or changing the flow velocity of the fluid and/or the flow direction of the fluid during the filling operation.

Abstract: A bonding means for electrically coupling a first component and a second component at an interface. The bonding means including at least one electrically conductive bonding puck positioned between the first component and the second component. The bonding puck being disposed within a recess formed in at least one of the first component and the second component. The at least one electrically conductive bonding puck providing electrical bonding between the first component and the second component and establishing electrical continuity therebetween.

Abstract: A lightning-protected conductive composite fuel tank includes a conductive material arrayed on an outer surface to at least partially cover a fastener centerline. Through holes extend along the fastener centerline through the conductive material and the underlying fuel tank shell. These through holes are countersunk into the fuel tank shell to a depth such that a fastener in a through hole will avoid electrical continuity or communication with the conductive material on the fuel tank outer surface. The gap in the countersunk through holes, between the fastener heads and the coextensive outer surface of the fuel tank, is filled with a dielectric or nonconductive material.

Abstract: Systems and methods for providing a structural adhesive film that includes a conductive scrim layer are disclosed. In one embodiment, a method for producing a structural adhesive film includes providing a first resin adhesive layer. The first resin adhesive layer is configured to bind to a first carbon fiber ply. The method also includes providing a second resin adhesive layer. The second adhesive layer is configured to bind to a second carbon fiber ply. The method also includes providing a conductive scrim that is embedded between the first resin adhesive layer and the second resin adhesive layer. In some embodiments, the conductive scrim is infused with resin adhesive.

Abstract: An aircraft telescopic in-flight refueling mast comprising a metallic structural beam (31), electrically connected to the aircraft by flexible conductive means (33), having inside a fixed metallic tube (11) and a metallic telescopic tube (11) providing the fuel conduit, and, attached to said beam (31), flight control surfaces (41) and protection means against electric discharges, specially lightning strikes and electro-static discharges, including insulated means (39, 51) and low conductive means (15, 17) for reducing the lightning currents at a safe level and for draining the static charge created during the refueling, and conductive means (19, 21, 23, 33, 43) providing a safe lightning current path and good electrical bonding for electro-static discharge.

Abstract: The present invention provides a shell arrangement as well as an aircraft or spacecraft comprising such a shell arrangement. The shell arrangement comprises a first lightning conductor layer for conducting lightning energy and a fibre composite layer supporting the first lightning conductor layer. Furthermore, the shell arrangement comprises a first electrical connection for connecting a first electrical component with the first lightning conductor layer. The advantage resulting according to the invention is that the lightning conductor layer fulfils a double function: on the one hand it serves to conduct lightning energy and on the other hand it forms a portion of a circuit for operating the first electrical component. For this reason, the need for electrical wiring in the airplane is reduced, in turn resulting in a weight reduction for the aircraft or spacecraft.

Abstract: A lightning-protected conductive composite fuel tank includes a conductive material arrayed on an outer surface to at least partially cover a fastener centerline. Through holes extend along the fastener centerline through the conductive material and the underlying fuel tank shell. These through holes are countersunk into the fuel tank shell to a depth such that a fastener in a through hole will avoid electrical continuity or communication with the conductive material on the fuel tank outer surface. The gap in the countersunk through holes, between the fastener heads and the coextensive outer surface of the fuel tank, is filled with a dielectric or nonconductive material.

Abstract: One embodiment of the invention facilitates automatic static discharge from an apparatus such as an aircraft. The embodiment comprises an attachment structure, such as a jet canopy, having a system grounding port. The attachment structure can be operatively coupled to an electrostatic discharge device having a contact side with a conductive surface and an attachment side with a resistive surface. The grounding conduit operatively couples the electrostatic discharge device to the system grounding port. The electrostatic discharge device is operatively coupled to the aircraft, thereby automatically discharging static electricity from the aircraft to ground.

Abstract: A cowling assembly for a vehicle includes a generally external surface having secured thereto or adjacent thereto, an elongate lightning protection strip member. The lightning protection strip member includes a lightning diverter strip connected to a lightning conductor strip. The lightning diverter strip at least when subjected to high electric field, enabling an ionized channel to be established along the diverter strip to divert the lightning along the lightning diverter strip to the lightning conductor strip. The lightning conductor strip conducts the lightning from the lightning diverter strip to an earth of the vehicle.

Abstract: A method and system of preventing lighting from puncturing composite surfaces is provided. The method includes reconfiguring plies of a composite surface so that a composite conductive ply is located on the outer surface of the composite surface and a non-conductive composite ply is located directly underneath the conductive ply and inserting a flashover point between an outer edge of the conductive ply and a fastener attaching the composite surface to a support structure.

Abstract: A system for protecting a composite-body aircraft from damage caused by lightning strikes includes a Faraday cage defined on the exterior surface of the aircraft body by a continuous, electrically conductive grid that extends to the outermost lateral periphery of the body. In one possible embodiment in which the aircraft's body includes a plurality of composite panels that are joined at their adjacent edges by splice plates, the conductive grid may advantageously be formed by electrically conductive splice plates, e.g., of titanium, that have their respective, adjacent ends electrically connected to each other, e.g., with conductive straps and fasteners. The conductive grid provides preferential attachment points and conductive paths for lightning strikes on the surface of the aircraft, thereby shielding the interior of the grid from lightning damage. The conductive grid can optionally function as a ground return path for the aircraft's electrical system.

Abstract: The invention relates to an integrated device (1) for the protection against electrical discharges of conductive fixing elements (2) between one another or of a fixing element and another conductive element of aircraft, comprising a cap (3) and an o-ring gasket (4) made of non-conductive insulating material, the mentioned integrated device (1) comprising a modified fixing element (2) working together with the cap (3) and the o-ring gasket (4), the fixing element (2) surrounding the cap (3) and the o-ring gasket (4) in a non-conductive manner, thus preventing the possibility of electrical discharges such that in the device (1) the number of necessary components is minimized, the impact in weight for the aircraft being minimum, the modified fixing element (2) further comprising a thread (5) on the outer face of the area that has to be protected.

Abstract: The invention relates to a device (12) for protecting a conductive fixing element (5) of an aircraft subjected to high charges against electrical discharges, the device (12) comprising a cap (6) made of non-conductive material, a washer (7) made of conductive metal material and an o-ring gasket (8) made of non-conductive material retained by the washer (7), the washer (7) being retained by the fixing element (5) subjected to a high charge that must be protected, and the cap (6) and the o-ring gasket (8) non-conductively surrounding the fixing element (5), thus preventing the possibility of electrical discharges.

Abstract: In a process for discharging a test mass that is free-floating in a surrounding electrode casing on board a satellite, the electrode casing is enclosed by a vacuum tank, and has one or more first electrodes for the application of electrostatic forces and/or moments to the test mass. In addition, the electrode casing also has one or more second electrodes for modulating alternating voltages (particularly, high frequency voltages) for measuring purposes onto the test mass as well as one or more light-emitting elements, which irradiate the test mass, the electrode casing and/or the electrodes particularly with ultraviolet light for generating a photoelectric effect. Automatically and iteratively, a test mass charge of the test mass is determined. A control operation for eliminating the determined test mass charge is carried out until the test mass charge has reached a defined target value.

Abstract: An electrical current return circuit for on-board avionic devices. A conductive metallic bar is attached to a conductive composite structure of an aircraft via insulating fixtures. The conductive metallic bar may be electrically coupled to on-board avionic devices so that a circuit is formed. A number of on-board devices may be connected to the circuit by way of various connector elements. The conductive metallic bar may also form part of a power grid.

Abstract: An apparatus comprises a wall, an internal structure, and a fastener. The wall has a conductive surface and a countersunk hole. The countersunk hole passes through the internal structure. The fastener has an interference fit within the countersunk hole.

Abstract: The present invention concerns a method of producing a lightning diverter for conducting a lightning-induced electrical current, which is to be placed on structures such as wings on wind turbines, aircraft components, radomes and the like with the purpose of lightning protection. The method comprises the steps of making a plurality of holes in a plate of an electrically conductive material, filling said holes at least partly with one or more electrically non-conductive materials, and then finally dividing the plate—preferably into strips. The lightning diverter obtained hereby consists of a layer of electrically non-conductive material with a plurality of isolated segments of electrically conductive material. The invention further relates to a diverter strip with isolated segments of concave shapes being advantageous because of the good connection between the segments and the non-conductive material.

Abstract: A system for lightning-protection of an aircraft skin panel that includes a nonconductive skin panel substrate and a series of spaced apart electrically conductive strips embedded in and extending along an outer surface of the nonconductive skin panel substrate. A series of electrically conductive fasteners extend through the nonconductive skin panel substrate to affix it to the airframe of the aircraft. The fasteners are arrayed along peripheral regions of the nonconductive skin panel substrate. Each of the electrically conductive strips is in electrical communication with the aircraft airframe through at least one fastener located proximate each end region of each strip.

Abstract: A lightning-protected conductive composite fuel tank includes a conductive material arrayed on an outer surface to at least partially cover a fastener centerline. Through holes extend along the fastener centerline through the conductive material and the underlying fuel tank shell. These through holes are countersunk into the fuel tank shell to a depth such that a fastener in a through hole will avoid electrical continuity or communication with the conductive material on the fuel tank outer surface. The gap in the countersunk through holes, between the fastener heads and the coextensive outer surface of the fuel tank, is filled with a dielectric or nonconductive material.

Abstract: An electrical insulating device for a linear component forming part of a fuel system subjected to risks of possible external electrical discharges formed by a part (13) made of insulating material attached to two metal flanges (15, 17) that allow inserting the device (11) between two parts of said linear component, said part (13) being formed by a cylindrical body (21) with a castellated crown (23) on its outer side, formed by longitudinal (25) and transverse (27) segments, and said metal flanges (15, 17) having transverse projections (31, 33) facing the transverse segments (27) of the castellated crown (23) for facilitating their attachment by suitable means (39).

Abstract: A single-path electrical device generates a conductive channel through the air to alternatively convey charge to a target and remove charge from the target. The single-path electrical device uses either a grounding sphere or grounding torroid to store and at least partially dissipate opposite charge. In this way, neither the target nor the single-path electrical device is required to be grounded. The single-path electrical device may operate at a low frequency to help overcome any surface effects of the target.

Abstract: Lightning strike protection system for aircraft fuel tanks made of low electrical conductivity composite material. The system comprises an electrical conductive thin wire mesh (1) that covers the whole external surface of the tank outer skin (I) made of composite and a thick wire metallic mesh (2) overlapping the mesh (1) at a minimum distance of 50 mm to both sides of a row of fasteners (III) joining the said outer skin (I) to one internal part (II) of either composite or metallic material. Both metallic meshes (1, 2) maintain electrical contact by their installation/assembly and by means of metallic countersunk head washers (3) connected to bonding points and set to the gap existing between the fastener (III) and the outer skin (I). The corresponding fabrication process is also described.

Abstract: A lightning protection system for protecting composite structures and a method of protecting composite structures from lightning strikes. A dielectric ply is fixed above and completely covers metal surface features, e.g., skin fasteners through a composite skin to a wing fuel tank. A conductive ply is fixed above and completely covers the dielectric ply and extends to an external connection to a platform ground. The conductive ply directs current from lightning strikes away from metal surface features, e.g., to the platform ground. Both plies may be adhesively backed and sequentially pressed into place.

Abstract: An apparatus and method for current protection from lightning strikes is provided. An apparatus for current protection comprises an electrically conductive strip affixed to a surface, such as a structural panel, and electrically bonded to a system current return strip to conduct electricity between the electrically conductive strip and a current return location.

Abstract: A current diverter strip is provided having a dielectric (22) located above a plurality of conductive segments (24). An insulator (30) is also provided among said conductive segments (24) and below said dielectric (22). When RF transparency is required, the conductive segments (24) can have a maximum dimension that is approximately ?th of a wavelength of the highest operating frequency of an antenna that may be communicating through the current diverter strip. The dielectric (22) may be colored to match the color of the structure to which it is implemented. Upon exposure to a strong electric field, the current diverter strip (20) forms an ionized channel above the dielectric (22). In various implementations, the current diverter strip may be radio frequency transparent, environmentally and chemically resistant, color matched to its surroundings, and/or can withstand repeated uses.

Abstract: The invention includes a method of mounting a component to the skin of an aircraft. The component can include a drain valve, a gas cap, other external fuel instrumentation such as sensors, and antennae. One aspect of the invention includes a new method of mounting a drain valve to an aircraft fuel tank. The drain valve in the method includes any conventional drain valve having a stem and a flange that surrounds the stem. The method includes applying a material around a drain opening of the fuel tank; the material directs an electric charge away from the drain valve.

Abstract: A lightning strike mitigation system for protecting a surface includes an inner insulating layer adjacent a surface to be protected, an outer insulating layer, and an intermediate layer formed from an electrically conductive material between the inner and outer insulating layers. The inner and outer insulating layers may be formed from an ablative insulating material containing no metal fill, an ablative insulating material containing a 15% Ni fill, or an ablative insulating material containing a 30% Ni fill. The electrically conductive material may be a mesh material or a foil material formed from an electrically conductive material or materials.

Abstract: Arrangements for preventing electrical energy from lightning strikes against aircraft dissipating via aircraft fasteners 10 in an aircraft structure of composite materials in which a fastener 10 is covered with a layer of an insulating material 30 and a layer of a conductive material 32 is arranged to cover the insulating material 30 and extend over and beyond the lateral edges of the fastener 10, and preferential dielectric breakdown paths are provided at the edges of the conductive layer 32 distant from the fastener 10 so that in the event of a lightning strike electrical energy is not dissipated via the fastener 10, risking arcing and sparking, but instead from the edges of the conducting layer 32 to the underlying aircraft skin 12.

Abstract: A deployable lightning protection apparatus particularly suited for use with an aircraft radome comprises a source of electrically conducting fluid, a deliver apparatus which delivers the conducting fluid flow across to the surface of the radome prior to a lightning strike; and a control unit for controlling the delivery apparatus. The conducting fluid across the outer surface of the radome provides a conductive path for the passage of electrical current resulting from a lightning strike and dissipating said current without damage to the radome. The apparatus allows lightning protection to be deployed in response to a change in atmospheric conditions indicative of a high probability of lightning strike and removed when the danger of lightning strike has passed.

Abstract: A static discharge cable is attachable to a rescue hook or other component being lowered by an aircraft. The cable has a first fitting attachable to the hook or other component, a second fitting attached to the first fitting, and a conductive cable attached to the second fitting. The first and second fitting are attached using a shear pin. Attached to the other end of the cable is a light holder.

Abstract: Provided are methods of manufacturing an electrostatically clean solar array panel and the products resulting from the practice of these methods. The preferred method uses an array of solar cells, each with a coverglass where the method includes machining apertures into a flat, electrically conductive sheet so that each aperture is aligned with and undersized with respect to its matched coverglass sheet and thereby fashion a front side shield with apertures (FSA). The undersized portion about each aperture of the bottom side of the FSA shield is bonded to the topside portions nearest the edges of each aperture's matched coverglass. Edge clips are attached to the front side aperture shield edges with the edge clips electrically and mechanically connecting the tops of the coverglasses to the solar panel substrate. The FSA shield, edge clips and substrate edges are bonded so as to produce a conductively grounded electrostatically clean solar array panel.

Abstract: An electrical ground (10) for use in a spacecraft comprising, a first surface (12) capable of emitting electrons by photoemission, at least one isolated conductive surface (18) and at least one conductive connector (20) in connection with the first surface (12) and the isolated conductive surface (18) such that excess electrical charge developed in the isolated conductive surface (18) is dispersed into the first surface (12).