> Precipitation static is a phenomenon that occurs on aircraft in flight. > Friction between liquid water and also ice crystals, sand, dust and > particulates and the aircraft skin causes charge to build up.
I don't think so ... My understanding is that the electrostatic charge buildup is due to friction with air molecules. In fact, the drier the air is, the bigger the buildup. Perhaps you mean that this built up charge discharges to liquid water, etc., and causes the precipitation static. > Perhaps you may remember the scene in "Hunt for Red October", in which a sub > crewman is zapped by a static charge during a helicopter to sub personnel > transfer? I always thought that was a bit over-dramatic, but hmmmm... In a previous incarnation, I used to work in the oil patch up in the Canadian Arctic. In the winter, because of the extremely dry air (often 10% relative humidity or less), ESD was a major problem with all our printed wiring boards. And when a helicopter brough us a load hanging on a sling, we made damn sure to have a heavy ground cable that we could touch to the sling first. The arcs we drew from this arrangement were quite impressive, to say the least. Being of a scientific bent, we were all curious, of course, about exactly how much energy was involved in this phenomenon. Unfortunately, we couldn't find anybody stupid enough to volunteer, so there is no test data to confirm if this is lethal or not. Pity ... :-) Cheers, Egon Varju
