Abstract: A spark containment cap plate with a base and two or more spark containment caps. Each cap has a cover portion which extends from the base and defines a cavity inside the cap, inside which an end of a fastener is enclosed. Also a fastener joint with a structure; two or more fasteners, each fastener having an end protruding from a surface of the structure; and a spark containment cap plate. The plate has a base and two or more spark containment caps. Each cap has a cover portion extending from the base and defining a cavity inside the spark containment cap inside which the ends of the fasteners. A cured sealing material is provided between the cap plate and the structure which secures the cap plate to the structure in such a position that each end of each fastener is enclosed within a spark containment cap.

Abstract: A method of securing a first structure to a second structure is disclosed including providing a jig assembly having spark containment caps carried by a jig; mounting the jig assembly on a structure so that the spark containment caps and the jig contact the first structure; securing the spark containment caps to the first structure by injecting adhesive material into contact with the first structure and the spark containment caps and then curing the adhesive material; removing the jig after the adhesive material has cured; and securing the first structure to the second structure with fasteners, each fastener having a tail which is inserted through the first and second structures and into a respective one of the spark containment caps.

Abstract: A method of joining a wing skin to a structural element of an aircraft wing. A locating through hole is formed in the structural element, extending along a path between a first side of the structural element and a second side of the structural element. A spark containment cap is attached to the first side of the structural element to covering an opening of the locating through hole. A portion of the wing skin is positioned on the second side of the structural element. A fastening through hole having a larger diameter than the locating through hole is formed through both the wing skin and the structural element and along the path of the locating through hole. A fastener is inserted into the fastening through hole and the structural element secured to the wing skin, an end of the fastener being covered by the spark containment cap.

Abstract: A method of securing a first structure to a second structure is disclosed including providing a jig assembly having spark containment caps carried by a jig; mounting the jig assembly on a structure so that the spark containment caps and the jig contact the first structure; securing the spark containment caps to the first structure by injecting adhesive material into contact with the first structure and the spark containment caps and then curing the adhesive material; removing the jig after the adhesive material has cured; and securing the first structure to the second structure with fasteners, each fastener having a tail which is inserted through the first and second structures and into a respective one of the spark containment caps.

Abstract: A method of joining a wing skin to a structural element of an aircraft wing. A locating through hole is formed in the structural element, extending along a path between a first side of the structural element and a second side of the structural element. A spark containment cap is attached to the first side of the structural element to covering an opening of the locating through hole. A portion of the wing skin is positioned on the second side of the structural element. A fastening through hole having a larger diameter than the locating through hole is formed through both the wing skin and the structural element and along the path of the locating through hole. A fastener is inserted into the fastening through hole and the structural element secured to the wing skin, an end of the fastener being covered by the spark containment cap.

Abstract: A method of securing a first structure to a second structure is disclosed including providing a jig assembly having spark containment caps carried by a jig; mounting the jig assembly on a structure so that the spark containment caps and the jig contact the first structure; securing the spark containment caps to the first structure by injecting adhesive material into contact with the first structure and the spark containment caps and then curing the adhesive material; removing the jig after the adhesive material has cured; and securing the first structure to the second structure with fasteners, each fastener having a tail which is inserted through the first and second structures and into a respective one of the spark containment caps.

Abstract: A spark containment cap for enclosing an end of a fastener protruding from a structure, the enclosed body having a base and a cover portion, the cover portion extending from the base, the base providing an adhering surface for adhering the spark containment cap to a structure, and the base and the cover portion together forming a cavity within the enclosed body inside which the end of a fastener can be enclosed.

Abstract: A spark containment cap forms a sealed cavity around an end of a fastener protruding from a structure. The cap has a cap body defining an air cavity enclosing the end of the fastener. The cap body includes an annular base (210) terminating at a base rim (211) surrounding an opening into the air cavity. An annular skirt of the cap provides an annular sealing volume extending around the base rim to receive an annular bead of a curable sealing material around the opening into the cavity to provide a seal between the cap body and the structure to seal a volume of gas within the cavity. The cap body includes a cap upper to receive the end of the fastener. The cap upper (220) is positionable so that an axis of the cap upper is offset from an axis of the annular skirt (230).

Abstract: A spark containment cap for forming a sealed cavity around an end of a fastener protruding from a structure is disclosed having a cap body with an annular base terminating at a rim which surrounds an opening into an air cavity arranged to enclose the end of the fastener. An annular sealing volume extends around the rim arranged to receive an annular bead of a curable sealing material around the opening into the cavity to provide a seal between the cap body and the structure to seal a volume of gas within the cavity. An engaging feature is configured to engage with the end of the fastener to prevent rotation of the fastener relative to the cap when the end of the fastener is received by the cap. A fastening system, a joint, an aircraft and a method of securing a fastener and a spark containment cap to a structure are also disclosed.

Abstract: A method of joining a first workpiece to a second workpiece is disclosed including securing a spark containment cap to the first workpiece, the cap comprising an electrically insulating washer and a cap body defining an air cavity. Once the cap has been secured, a tail of a fastener is inserted into the air cavity through the second workpiece, the first workpiece and the washer. Upon tightening the fastener, the tail of the fastener urges the washer against the first workpiece and the first and second workpiece are thereby clamped between the washer and a head of the fastener so as to form a joint. Advantageously, it has been found that forming a joint in this manner can help to better protect the joint from the effects of electrical arcing.

Abstract: A spark containment cap for enclosing an end of a fastener protruding from a structure, the enclosed body having a base and a cover portion, the cover portion extending from the base, the base providing an adhering surface for adhering the spark containment cap to a structure, and the base and the cover portion together forming a cavity within the enclosed body inside which the end of a fastener can be enclosed.

Abstract: A spark containment cap forms a sealed cavity around an end of a fastener protruding from a structure. The cap has a cap body defining an air cavity enclosing the end of the fastener. The cap body includes an annular base (210) terminating at a base rim (211) surrounding an opening into the air cavity. An annular skirt of the cap provides an annular sealing volume extending around the base rim to receive an annular bead of a curable sealing material around the opening into the cavity to provide a seal between the cap body and the structure to seal a volume of gas within the cavity. The cap body includes a cap upper to receive the end of the fastener. The cap upper (220) is positionable so that an axis of the cap upper is offset from an axis of the annular skirt (230).

Abstract: A spark containment cap for forming a sealed cavity around an end of a fastener protruding from a structure is disclosed having a cap body with an annular base terminating at a rim which surrounds an opening into an air cavity arranged to enclose the end of the fastener. An annular sealing volume extends around the rim arranged to receive an annular bead of a curable sealing material around the opening into the cavity to provide a seal between the cap body and the structure to seal a volume of gas within the cavity. An engaging feature is configured to engage with the end of the fastener to prevent rotation of the fastener relative to the cap when the end of the fastener is received by the cap. A fastening system, a joint, an aircraft and a method of securing a fastener and a spark containment cap to a structure are also disclosed.

Abstract: A method of joining a first workpiece to a second workpiece is disclosed including securing a spark containment cap to the first workpiece, the cap comprising an electrically insulating washer and a cap body defining an air cavity. Once the cap has been secured, a tail of a fastener is inserted into the air cavity through the second workpiece, the first workpiece and the washer. Upon tightening the fastener, the tail of the fastener urges the washer against the first workpiece and the first and second workpiece are thereby clamped between the washer and a head of the fastener so as to form a joint. Advantageously, it has been found that forming a joint in this manner can help to better protect the joint from the effects of electrical arcing.

Abstract: A spark containment cap for forming a sealed cavity around an end of a fastener protruding from a structure, the cap comprising: a cap body defining an air cavity arranged to enclose the end of the fastener, and including an annular base terminating at a base rim which surrounds an opening into the air cavity; and an annular skirt to provide an annular sealing volume extending around the base rim arranged to receive an annular bead of a curable sealing material around the opening into the cavity to provide a seal between the cap body and the structure to seal a volume of gas within the cavity. The cap may further include a fastener engaging portion that engages with a threaded portion of the fastener so as to secure the cap to the fastener.

Abstract: A spark containment cap for forming a sealed cavity around an end of a fastener protruding from a structure is disclosed having a cap body with an annular base terminating at a rim which surrounds an opening into an air cavity arranged to enclose the end of the fastener. An annular sealing volume extends around the rim arranged to receive an annular bead of a curable sealing material around the opening into the cavity to provide a seal between the cap body and the structure to seal a volume of gas within the cavity. An engaging feature is configured to engage with the end of the fastener to prevent rotation of the fastener relative to the cap when the end of the fastener is received by the cap. A fastening system, a joint, an aircraft and a method of securing a fastener and a spark containment cap to a structure are also disclosed.

Abstract: A cap is disclosed having a collar portion with three or more contact regions arranged to contact the end of a fastener around which the collar portion is provided, the collar portion having a lobed shape in cross-section such that an outwardly projecting lobe extends between each neighbouring pair of contact regions. An advantage of this lobed arrangement is that the cap can tolerate relatively large manufacturing tolerances at the fastener end. The cap may be for fitting over a nut or fastener head, with the contact regions of the cap being arranged to contact corresponding contact regions on a cylindrical collar base portion of the nut or fastener head. The diameter of this cylindrical collar portion may not be well controlled, so that the manufacturing tolerance is high. The lobed shape of the cap base ensures that the contact regions will always provide a good frictional engagement with the nut, whether the cylindrical collar is undersized, oversized, or at its nominal diameter.

Abstract: A cap for forming a sealed cavity around an end of a fastener is disclosed. The cap has a cap body with an annular base terminating at a base rim which surrounds an opening into a central cavity. The cap also has an annular skirt providing an annular pocket between the skirt and the base. An inlet hole is provided in the skirt which is in fluid communication with the annular pocket. A protuberance protrudes in the annular pocket and faces the inlet hole to promote a flow of sealant injected through the inlet hole to flow annularly around the annular pocket.

Abstract: A cap for forming a sealed cavity around an end of a fastener protruding from a surface of a structure is disclosed. The disclosure relates to a spark prevention cap. The cap has an annular base with an annular base terminating at a base rim. The base rim surrounds an opening into a central cavity for receiving the end of the fastener. The base rim lies in a base rim plane around at least a majority of a circumference of the annular base. An annular skirt provides an annular pocket in which a sealant material is received. A biasing configuration is configured to positively bias the base rim against the surface of the structure.

Abstract: A cap configured for providing a sealed cavity around an end of a fastener and a method of bonding a cap to a structural member in which a contact adhesive is provided for fixing the cap to the structural member and a curable sealant is provided for bonding the cap to the substrate.