Spark containment cap

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 having 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 extending around the rim arranged to receive a 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;
• and
• an engaging feature 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 method of securing a fastener and a spark containment cap to a structure, the cap including a cap body having a cavity, and the method comprising:

• disposing a spark containment cap with a first fastening member of the fastener retained in the cavity over an aperture in the structure;
• providing an annular bead of uncured sealing material between the structure and the cap;
• curing the bead of sealing material;
• and
• inserting a second fastening member of the fastener through the aperture and fastening the second fastening member with the first fastening member after the bead of sealing material is cured.

A spark prevention rivet for securing through an aperture in a structure, the rivet comprising:

• an elongate stem with a head;
• a sleeve extending around the elongate stem and slidable along the elongate stem;
• the stem having a tapered portion tapering inwardly away from the head;
• the sleeve having a structure locating feature and an internal tapered surface corresponding to the tapered portion;
• wherein, upon drawing the stem through the sleeve to draw the head towards the structure locating feature, at least part of the sleeve is caused to deform outwardly and at least part of the internal tapered surface of the sleeve forms an interference fit with the tapered portion of the stem.

An aircraft comprising at least one of

• 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 having 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 extending around the rim arranged to receive a 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, and an engaging feature 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 comprising the spark containment cap, and a fastener comprising a first fastening member and a second fastening member, the cap body being configured to receive the first fastening member so that the engaging feature engages the first fastening member, and the second fastening member being rotationally fastenable with the first fastening member;
• and,
• a spark prevention rivet for securing through an aperture in a structure, the rivet comprising an elongate stem with a head, a sleeve extending around the elongate stem and slidable along the elongate stem, the stem having a tapered portion tapering inwardly away from the head, the sleeve having a structure locating feature and an internal tapered surface corresponding to the tapered portion, wherein, upon drawing the stem through the sleeve to draw the head towards the structure locating feature, at least part of the sleeve is caused to deform outwardly and at least part of the internal tapered surface of the sleeve forms an interference fit with the tapered portion of the stem.