Q&A: Why don't planes crash when they get struck by lightning?
Have you ever heard the news that a plane got struck by lightning, but then they said it didn't crash and no one on the plane got hurt?
If do, you might have wondered how is it even possible for a plane to get struck by lightning and not crash?
Well, truth be told, while lightning strikes on flying aircraft don't happen every day, they do occur on a fairly frequent basis.
So why don't we hear occasional news reports of a lightning strike bringing down an airplane?
Well, the answer lies in a plane's outer skin...
A plane's aluminum shell acts as a Faraday cage which shields the internal components of the plane and its passengers from the massive power surges delivered by lightning bolts.
In a nutshell, the electric charge from a lightning strike flows across the exterior of the plane's metallic skin without ever penetrating the plane. Thank goodness for aluminum!
But wait... Newer aircraft are made of non-conductive composite materials that don't provide any Faraday protection. Shouldn't those plane be knocked out of the sky by lightning?
The answer is yes, but that danger is mitigated by adding a thin layer of metallic mesh to the plane's outer skin. This mesh layer adds the missing Faraday protection that's present by default in aluminum-skinned planes.
But what about the plane's sensitive electronic gear?
Even with their outer shells protecting the insides of planes, on rare occasions a powerful electrical surge can still make its way into a plane's crucial electrical system.
Luckily, that risk is mitigated as well by shielding the plane's wiring and electrical components with metallic Faraday cages of their own. And just to make sure disaster doesn't happen, the most critical electronic devices have duplicates that serve as backups, just waiting to spring into action if needed.
Bottom line: "Faraday cage" protection allows airplanes to take direct hits from lightning bolts in mid-air and keep right on flying to their destination with little to no damage being done to the aircraft.