Re: Snowstorms and electrical charges

Date:         13 Feb 99 02:25:55 
From:         kts@socrates.berkeley.edu (Katie Schwarz)
Organization: University of California, Berkeley
References:   1 2
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Ken Ishiguro  <kenish@earthlink.net> wrote:
>Yes, dry blowing snow can build up a static charge.  My friend who grew
>up on a ranch in Colorado learned at a very early age to never touch a
>metal fence in cold, windy, dry conditions!  Aircraft can build up a
>static charge from snow, rain, or just the friction of the air across
>the fuselage.
>
>Aircraft are equipped with devices to drain off static buildup in
>flight, so the airplane story is urban legend as you state.

I finally dug out the magazine where I read the story about the
airplane that had a huge static discharge after flying into dry
blowing snow.  It was _Flying_ magazine, July 1994, column "I
Learned About Flying From That" by Matthew Nash, who was the
copilot.  Here are some excerpts:

"On an overcast night in late December we were flying on a scheduled
flight from Lynchburg, Virginia, to Pittsburgh in a Swearingen
Metroliner III. ... We plunged into the overcast at 17,000 ... Dry ice
crystals hissed across the windshield abrasively like blown sand, and
the captain switched on the recognition lights."

Then suddenly:
"For only a moment, the long nose of the Metro flared with a
brilliant, searing light.  Then with a deafening roar, there came a
tremendous explosion of light, like a massive flashbulb exploding
right outside the windshield.  The cockpit got dark and everything got
very quiet.

"To say that we were stunned is an understatement.  We were floored,
and for a dazed second we charged ahead with numbed senses, only dimly
aware that the engines continued to run and the plane was still flying.
...

"The captain was screaming something but I couldn't hear him -- the
headset I now wore was useless.  Then the cockpit lights flickered on
and just as quickly went out again.  In that second, I caught some
gibberish in the headset.  The lights, radios, every electrical thing
clicked on again.  Then went out. ...

[captain turns off all generators, resets them, turns back on, climbs
out of the overcast]

"Subsequent inspection of the airplane revealed a hole the diameter of
a pencil where the electrical charge had penetrated the radome. ... I
have only heard of this phenomenon happening one other time ... in
very rare instances the charge is so huge and can build up so quickly,
the entire airplane can actually become a static wick."

--
Katie Schwarz
"There's no need to look for a Chimera, or a cat with three legs."
                         -- Jorge Luis Borges, "Death and the Compass"