Ken Jantz wrote:

Besides the voltage potential in the lightning strike, there is
considerable static potential in the area of one.  The damage from a
bolt results in whatever is in its way providing an easier path to
ground, or a potential difference in the case of cloud to cloud, than
the surrounding air.  (Birds can perch on high power lines for much
the same reason, as long as they don't touch ground, or the other
wire, which is essentially a ground).  Problem is, you may never know
when you (your plane) are in the ground path or not.  If not the
damage to larger aircraft systems will not be noticeable.

Electronics, and especially semiconductor devices (which most
everything is), are extremely sensitive to potentials (voltages).
Power supplies for these devices typically run between 3 & 7 volts,
with the actual devices using milli and micro voltages (sometimes at
high current yielding considerable heat).  To them, an increase of a
millivolt for even a microsecond would look like 440 volts going to
your 120 volt refrigerator.  The wires supplying main power would show
no damge, but inside the semiconductor would look liked a bombed out
city.  (Ergo, use a line conditioner for your computer, entertainment
electronics, etc., or unplug them during a severe electrical storm).
So, poof, there goes your state of the art avionics and possibly
engine control unit.

These low potential, low current transients are major problem for
manufacturers, not only of the device manufacturers, but also of the
OEM's who use them.  Major precautions are taken to ground work
surfaces, floor surfaces, tools, equipment, and personnel.  And if
that isn't enough to make you wonder how high tech electronics
continue to work consider that any device is a number of discreete
circuits in one package.  Any one of which may be damaged, but never
show up until it is called into play (latent defect).  If that were a
circuit which responds to emergencies, one would never know until it
was supposed to work and didn't.

But, take heart, these devices are hardy and have been used for years
without catastrophic results.  But, a lightning strike is a
catastrophy in and of itself and to most everything around it.

Stay miles away from those thunderstorms. I was coming back from Oshkosh
one time in the 182 and saw one off in the Wyoming distance. I landed at
the 
next opportunity and tied the Cessna down real well with chains.
Call me chicken. There are old pilots and there are bold pilots.

Paul Lamar
 
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