A University of Dayton Research Institute chemist who identified a plausible cause for the explosion that downed TWA flight 800 in 1996, has developed a self-healing wire designed to prevent a similar kind of explosion.

Bob Kauffman and his colleagues at UDRI were part of a team hired to determine the cause of the centre-wing fuel tank explosion that brought down TWA 800 killing all passengers and crew on board. The researchers determined that frayed fuel sensor wiring was to have played a significant role in the explosion.

Research showed that frayed wires exposed to moisture in a fuel tank cause conductive fuel residues to form. Kauffman explained: “If those residues are exposed to DC electricity from faulty wiring, they become red hot and can ignite the surrounding fuel.”

Kauffman’s solution if a PATCH – Power-Activated Technology for Coating and Healing – for wire insulation. The inexpensive and non-toxic formula draws on water and electricity to chemically transform itself into a permanent coating.

The PATCH system comes in two forms – both based on polyvinyl alcohol. One is a water-based liquid, similar to contact lens solution, that can be misted into hard to reach compartments, the other is a solid, water-soluble material, much like coatings used on vitamins and in pain relief tablets, to be embedded as an inner layer of coating during wiring manufacture.

Kauffman explained: “The liquid can be sprayed directly onto wire bundles. If it comes into contact with any live wire with damaged insulation, the electrical current will transform the spray into an insoluble polymer coating. Any solution not coming into contact with exposed wire will wash away, preventing weight-build-up from repair activity.”

The solid PATCH is built into the wiring between the copper wire and its insulation. Already in contact with electrical current, the chemical coating needs only water to transform into a permanent repair – which takes place when the insulation is breached.

Kauffman explained: “When a plane lands, it’s full of water, which explains why condensation occurs when an aircraft descends from freezing, high-altitude temperatures to warmer low-altitude temperatures. “So if there is a break in the outer insulation, moisture inside the aircraft activates the chemical process that transforms the soluble inner coating into a permanent seal.”

A secondary discovery by Kauffman could also prove lifesaving. During his research, Kauffman realised that damaged aircraft wires exposed to moisture emit radio frequencies just before they short out – a phenomenon that could allow them to be readily located with a simple ‘listening’ device before they cause any damage.

According to Kauffman, technicians could use hand-held listening devices to locate faulty wires, or the devices could be planted on runways to listen for ‘chatter’. The same technology could also be applied to industrial applications.