How come airplanes don't crash when they're struck by lightning?
user
Actually they do sometimes, though it's unusual.  As it turns out, thunderstorms produce intense bursts of static electricity, and can discharge up to 50,000 amps into the air.  But there's a reason you're seeing planes in the sky, rather than falling out of the sky.  It's the result of the planes having a kind of protection called a Faraday cage.  The purpose of the cage is to block the charge that would otherwise flow through your airplane if you touched it while it was in the thunderstorm.  As long as you've got one of these, you're probably fine.
assistant
How are airplanes considered faraday cages?
user
The Faraday cage blocks any electric charge that would otherwise flow into the plane through the wire, and transfers the charge to the outside of the plane.  Because it happens on the outside of the plane, the static charge of the lightning is dissipated to the air through the surface of the plane, rather than traveling through the interior of the plane.  That's what makes it safe!
assistant
Does this have to do with the plane's material?
user
Yes, Faraday cages are made from conducting materials.  Typically aluminum or copper, though sometimes they're also made from graphite.  It's pretty important that you have the proper metal, which must conduct electricity.
assistant
How come airplanes don't crash when they're struck by lightning?
user
Actually they do sometimes, though it's unusual.  As it turns out, thunderstorms produce intense bursts of static electricity, and can discharge up to 50,000 amps into the air.  But there's a reason you're seeing planes in the sky, rather than falling out of the sky.  It's the result of the planes having a kind of protection called a Faraday cage.  The purpose of the cage is to block the charge that would otherwise flow through your airplane if you touched it while it was in the thunderstorm.  As long as you've got one of these, you're probably fine.
assistant
How are airplanes considered faraday cages?
user
The Faraday cage blocks any electric charge that would otherwise flow into the plane through the wire, and transfers the charge to the outside of the plane.  Because it happens on the outside of the plane, the static charge of the lightning is dissipated to the air through the surface of the plane, rather than traveling through the interior of the plane.  That's what makes it safe!
assistant
Does this have to do with the plane's material?
user
Yes, it's probably the most important factor, though the number of Faraday cages and the surface area of the plane are also important.
assistant
How come airplanes don't crash when they're struck by lightning?