Ignition Hazards from Intermittent Electrical Contacts 2001-01-2913

For conventional metallic aircraft lightning protection methodologies have generally been well established by years of flight experience. However, recent events have highlighted the need to take into account the effects of age or existing fault conditions.

For lightning this could mean currents being conducted across unbonded couplings, across bond straps which make intermittent contact, or by debris or chafed wires bridging to fuel gauges and their wiring.

The paper discusses the effects of transient currents flowing through intermittent contacts, and the levels at which such transients present a potential threat for fuel ignition. In the main this is a review of existing data, but supported by experimental studies which are just beginning at Culham.

The work has been carried out under the European EM-Haz and the Culham Lightning Club programmes