Message-ID: <38B7F961.2B073671@regandesigns.com>
Date: Sat, 26 Feb 2000 10:03:45 -0600
From: Brent Regan <brent@regandesigns.com>
To: Lancair List <lancair.list@olsusa.com>
Subject: RE: Electrical bonding for static buildup
Mime-Version: 1.0

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When a metal airplane flies, the dust and precipitation in the air impacts
the surface of the airplane and knocks off electrons. The airframe becomes
electrically charged, compared to terra firma. Upon landing the rubber tires
insulate the charged airframe. At the fuel truck, the chargeless line monkey
gets within arcing distance with the metal fuel nozzle. Because all things
want to be equal, the resident charge on the airframe is CONDUCTED by the
metal in the airplane through the metal nozzle and into the conductive line
monkey. If the resulting spark has enough energy and the local air fuel
mixture is near stochiometric, a bad thing will happen. BOOM!

>From the standpoint of static charge, Lancair IVs are conductive due to the
carbon fiber.

If you rub a balloon on a cat, both will become charged (one positive and
one negative) and you will be lacerated. Most of the charge in the cat will
transfer to you through the cats claws, aided by your blood (a good
conductor). The balloon is another story. Because the balloon is not
conductive, the charge remains in the localized areas that were rubbed on
the cat.

Because the balloon is non conductive, the charge cannot be drained off at a
single point to create a spark.

Because the balloon is non conductive, the charge cannot be drained off at a
single point to create a spark.
(worth repeating)

One could argue that a 360 is a lot closer relative to a balloon than a
chunk of aluminum. One could also argue that connecting the metal ring at
the fuel filler to the other metal parts of the airplane would provide a
path for an accumulated charge and would therefore be MORE likely to arc
than an non-bonded (insulated) ring.

IMHO it would be a good idea to have a convenient point to connect a ground
strap to the airplane and be sure to use it whenever you are fueling.

Regards
Brent Regan

Reflect on this "Stsaerb Egral Evil Gnol"


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