Why Planes Are So Good at Withstanding Lightning Strikes

A photo taken by MNN's Catie Leary of a lightning bolt striking close to an aircraft in Atlanta. . (Photo: Catie Leary/MNN)

A dramatic video showing the exact moment a Delta Airlines Boeing 737 was struck by lightning in preparation for takeoff has gone viral - and, reasonably enough, caused something of a concern.

While frightening, the good news is that lightning striking a plane rarely results in any more damage than burnt paint. In fact, it's estimated that every plane in the U.S. commercial fleet is struck by lightning at least once every year. The reason we rarely hear anything about it is because the FAA maintains strict lightning certifications for all aircraft manufacturers. From the smallest electronic circuit to the person sitting next to you, planes are designed and engineered so that lightning can't touch anything of vital importance.

But where does it all go?

Since a plane's outer-shell is made mostly of aluminum, it provides a great conductive surface for lightning to travel along. It's important to note that lightning never travels inside a plane thanks to protective shielding, grounded wires, and other defensive measures. Instead, it enters and leaves along discharge points like a gutter directing water away from a roof.

lightning plane
A Boeing diagram showing how a lightning strike both enters and leaves a plane at various discharge points. (Photo: Boeing)

Is there any serious damage that can occur?

Since we're talking about a force of nature that can reach average temperatures of over 53,000 degrees, there are sometimes minor repercussions that can occur on a plane's body from a strike. The most recent example occurred this past April when a lightning strike on an IcelandAir Boeing 757 left a giant hole in the nose of the aircraft. Nevertheless, the flight continued on and no one was hurt. Thanks to engineering with a focus on dealing with and protecting from adverse lightning strikes, it's been over 45 years since a U.S. commercial aircraft crashed due to lightning.

How scary is it to be on a plane when lightning strikes?

It depends. Passengers have reported everything from a very large bang to a bright white light to, well, nothing at all. In fact, most passengers don't even realize a plane has been struck. Check out the vides below for examples what sounds like a dull thud against the plane.

Anything else?

Yes. It should be noted that despite all the necessary precautions against lightning, pilots rarely choose to fly through storms. Violent updrafts, downdrafts, and winds of up to 150 mph are the big reasons - as well as limiting any potential strikes from lightning. As this flight path posted to Reddit shows, commercial pilots hate storms just as much as you do.