KART 25.921 Lightning Research Program for Fastener Sparking Threshold Database
Topic:
KART 25.921 Lightning Research Program for Fastener Sparking Threshold Database
Presenter:
Cody Weber, EMA Principal Scientist II
Bill Martin, EMC Expert
Brock Milford, HIRF and Lightning Engineer, NIAR Environmental Test Lab
Ernie Condon, Senior Research Engineer, Wichita State University National Institute of Aviation Research
Abstract:
NIAR and EMA® have completed two phases of a research program with the goal of creating an industry and FAA-endorsed compliance approach with a fastener sparking threshold database to support aircraft fuel tank lightning compliance associated with §25.981 and §25.954. This webinar will summarize efforts from two phases of the research program. Phase I focused on the development of the fastener sparking threshold database. Test articles containing single and quadruple fastened joints were collected from several major OEMs in nominal and failure mode fastener installations. Lightning current levels that produced sparking and other measured parameters were collected in NIAR’s lab. Phase II of this research program was to develop a computational electromagnetic simulation approach that could reliably determine current densities in aircraft fuel tank regions to establish appropriate specimen injection levels. EMA® developed the simulation model in EMA3D® Cable (now Ansys EMC Plus) and compared simulation results to full wing low-level lightning pulse test results performed by NIAR. The correlation between test and simulation gives high confidence in the ability of simulation to supplement and expand beyond lightning characterization by testing alone.
