Lightning tends to seek out metal components on a composite skin, including metal fasteners. FTI (hall 5, A2) has developed a system for ensuring that the energy dissipates rapidly - and without sparking - into the metal mesh embedded in the wing or fuselage skin for precisely that reason.
Seattle-based FTI's Kevin Loveall explains that the key is in ensuring that metal fasteners are embedded so precisely and tightly into the anchoring hole that they make firm contact with the embedded mesh without the need for adhesive.
FTI has developed a system for embedding metal bushes in the composite surface in such a way as to ensure the necessary contact, then the metal fastener - whether one of FTI's or manufactured by anyone else - can be fitted into the bush.
FTI says it has successfully tested its fittings to 240,000 amps with negligible damage. This exceeds the statutory maximum test by 40,000 amps.
Source: Flight Daily News
