Overview: The equipment may be mounted on the outside of the fuselage or in the vertical stabilizer and the concern is that the direct strike, or the high E and H fields associated with a nearby strike, may damage or disrupt the electronics. For example, erase the flight data and voice data in the memory of a deployable black box /Emergency Locator Transmitter (ELT).
It will be shown that when a metal enclosure with an antenna mounted above it is enclosed in a nylon or fiberglass outer enclosure, that the lightning strike is to the composite skin surface, with embedded wire mesh, either side of the enclosure, and not to the non-conductive enclosure. The need for a diverter strip, in the top of the non-conductive enclosure, for protection which may affect the performance of an antenna inside the enclosure, is thus obviated.
The magnetic field and electric field inside the EUT as well as the voltage induced into the cables is computed for a nearby lightning strike as well as to the vertical stabilizer.
The current induced into the ELT antenna and transmitter is computed as well as potential protection techniques.
Speaker: David Weston
David A. Weston is an electromagnetic compatibility (EMC) consultant and certified National Association of Radio and Telecommunications Engineers (iNARTE) EMC engineer at EMC Consulting Inc. Merrickville, Ontario, Canada. A life member of the Institute of Electrical and Electronics Engineers, Weston has worked in electronic design for 55 years , specializing in the control, prediction, measurements, problem solving, analysis, and design aspects of EMC for the last 44 years.
He is the author of the third edition of the 1,157-page book Electromagnetic Compatibility, Methods, Analysis, Circuits, and Measurement published by CRC press in 2017, as well as numerous papers of a practical nature.