Dan Jacobson wrote:
GIF of plane hit by lightning:
http://bm6aak.myweb.hinet.net/file/456.gif
(Lightning hits planes everyday and is no big deal.)
What it clearly shows is that airplanes do not get "hit
by lightning". What actually happens is that a lightning
bolt already headed from ground to cloud sometimes
makes a small detour through a conductive object (airplane)
if it happens to be where the lightening bolt may have gone
anyway.
There are billions of volts cloud-to-ground before the strike.
Once the air in the lightning bolt path is ionized, the
current that flows is only a few thousand Amps.
A metallic aircraft, if it becomes part of the current path,
has a max voltage drop across it of only a few hundred volts.
The airplane is self-protected in the same way as installing
a #8awg copper wire from a "lightening rod" from the roof of
a barn, around the outside of the barn, to a ground rod.
During a strike, the potential from tip of the lightening
rod to the ground under the barn is constrained to a few
hundred volts... This keeps the destructive current path out
of the wood; it flows along the copper wire instead of in the
wood.
Dont try this with a plastic, composite or wood aircraft.
The current pulse instantly turns absorbed moisture into steam,
literally blowing the aircraft apart.
MikeM