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Successful lightning protection design is important for the CargoLifter CL 160 large non-rigid transport airship. Non-rigid airships, like balloons, have few hard structures so alternative means need to be designed to collect and conduct lightning currents. The helium lifting gas ionizes at one third the field intensity required for air so spark formation in ambient electric fields is more likely to originate inside a helium filled envelope than in the air outside of it. Protection development is being accomplished by a combination of high voltage strike attachment tests on scale models, and numerical analyses of electric fields.

A companion paper in this conference gave an overview of the Joint Radome Programme results (paper 2322). This paper reports on experiments that were able to reproduce some features of the failures to radomes that had occurred in-flight despite passing ground based tests. The electric field environment reviewed in the programme suggested that for most lightning strikes a more realistic test was to use a destressed electrode and the slower high voltage waveform D, rather than a rod electrode and a faster waveform A. Moreover other recent work also reported at this conference by Drumm et al, suggested that segmented divertor strips require higher light up voltages for slower voltage gradient waveforms. Therefore a series of tests with this revised test configuration have been conducted on some A320 radomes supplied by DGA Toulon France equipped with segmented strips that had experienced in-flight failures.