Here's Why Planes Can Be Struck by Lightning and Be Fine
There are few things more alarming for an airplane passenger than to look out the window and see a lightning storm. After all, you’re flying in a metal tube through the sky and it looks like you're inches away from bolts of pure electricity. It seems like a recipe for the kind of catastrophe that ends up in headlines. In reality, though, when it comes to lightning and planes, the plane always wins. In fact, it’s estimated that on average, lightning hits each aircraft once a year—or once per every 1,000 hours of flight time. Yet, lighting hasn’t brought down a plane since 1963.
Airplanes are designed to withstand hundreds of thousands of amperes of electricity—far more electricity than a lightning bolt can deliver. An airplane’s first round of defense is ensuring that fuel tanks and fuel lines are fully encased so that it almost impossible for a lightning spark to trigger a fuel explosion.
Adding to that safety precaution, the skin of airplanes—aluminum in older planes, a composite in more modern models—is designed to conduct electricity off of the plane. When lightning strikes a plane, it sends up to 200,000 amperes of electricity rocketing into the plane’s skin. The electricity follows the outer surface of the plane’s frame and then jumps back into the air, thanks to little antenna-like devices called static wicks.
Typically, there’s no sign that a plane was struck by lightning at all. If there is evidence of a lighting strike, it’s usually minimal damage to wing tips or the tail, which can act as lightning rods, or is seen in small entrance and exit burn marks. If a plane is struck by lightning, it is checked out by ground crews and usually quickly cleared for its next flight, like when lightning hit a plane flying from Abu Dhabi to Paris.
As airplanes become more dependent on advanced electronic equipment, there has been some concern that the static that builds up in planes (which naturally occurs during flight even without lightning) could damage delicate electrical systems. So far that has not been the case, thanks to continual research and improvements in lightning safety on airplanes. As technology improves and evolves, so do the lightning protection rules within the aeronautics industry.
In addition to the aeronautical engineering that makes modern planes practically lightning proof, advances in radar technology have made it easier for pilots to avoid thunderstorms all together. Pilots work with ground crews as well as other pilots to relay information about weather patterns and hopefully move around storms by a wide margin, skipping not only lightning but also the hail, wind, and turbulence that frequently accompany storms.
Strangely, the greatest potential danger from lightning hitting an airplane is when a plane is on the ground. Activities like refueling, loading luggage, and using metal staircases instead of enclosed jetways to deplane passengers can be dangerous in a lightning storm. While it’s frustrating for passengers stuck on a plane on the tarmac, it’s much safer to keep the plane door closed and wait for the lightning storm to pass.