Monday, June 1, 2009

Have your ever seen a toad struck by lightening?

One of Hally Berry's few good lines in X-men. An Airbus-330 airliner enroute from Rio de Janerio to Paris is overdue, presumed lost. The home office suggested that it might have been struck by lightening over the Atlantic. Maybe, but I don't really believe it.
My Air Force squadron had two F-106 fighter planes struck by lightening back in the 1960's. Both planes landed OK. One suffered electrical damage to an antenna, sufficient to warrent replacement, but not so bad as to knock out the radio.
Lightening strikes on aircraft are not uncommon but very seldom do much damage. Since the aircraft is not grounded, being high in the air, the full current of the bolt has not where to go. Plus what current does flow thru the aircraft flows thru the highly conductive aluminum skin.
Maxwell's field equations say that electric fields cannot exist inside a conductive shell, which means the aluminum fuselage offers highly effective shielding to everything (passengers, fuel, electrical and electronic equipment) inside it.
The "lightening did it" press release sounds more like "it wasn't our fault".

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