Static Electricity Hazards in Aircraft Fuel Systems.
Abstract
Static discharges that occurred during fueling in small-scale test rigs which simulated aircraft fuel tanks containing open-pore polyurethane foam were used to develop design criteria with respect to foam type, inlet configuration, and JP-4 conductivity. Blue polyether foam is more electrostatically active than red polyester foam; sparks can be eliminated only with a multiple orifice inlet and a minimum fuel conductivity level of 50 pS/m, achieved by adding anti-static additive. With red polyester foam, either the multiple orifice inlet or minimum conductivity fuel suppresses static discharges. Spark energies from blue foam or from high velocity single orifice inlets appear to be 10-100 times greater than from red foam or from multiple orifice inlets. Variables such as flow rate, inlet type and exit velocity, metal charge collectors, fuel conductivity, foam dielectric properties, and other non-metallic fuel components were studied. For example, a rubber bladder cell is not significantly different from an empty tank in terms of static discharges. An aluminum mesh substitute for open-pore foam proved to be effective in minimizing static buildup but produced unacceptable metal fragments which acted as charge collectors. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1978
- Accession Number
- ADA061450
Entities
People
- John M. Ferraro
- William F. Taylor
- William G. Dukek