Lightning Strikes Aircraft More Often Than You Thought
While you might think it’s rare, on average, every passenger plane is struck by lightning once a year. And yes, it is not dangerous.
In 2019, the world’s commercial aircraft fleet consisted of 25 900 aircraft. On average, an aircraft gets struck by lightning once a year. This means there are tens of thousands of cases each year where a commercial airliner was struck by lightning. Yet in recent decades no serious incidents have emerged.
The Last Incident
The last fatal incident where a commercial airplane crashed due to being struck by lightning dates back to 1963 when lightning struck Pan Am’s aircraft. The plane immediately caught fire and plummeted from the sky. After the 1963's incident, a lot of important lessons were learned. These days the aircraft are carefully designed to withstand the power of lightning.
What Typically Happens When Lightning Strikes a Plane?
When the lightning bolt hits the aircraft, the passengers inside can hear a loud boom in addition to seeing a bright flash.
Lightning typically strikes the airplane to its nose or to its wings. The aircraft intentionally is wired in such a way that the electricity of the lightning bolt continues flowing through the plane’s wires towards the tail of the plane from where it then leaves the plane. The exterior of an aircraft acts as a protective shell (a Faraday cage) for the interior of the plane, e.g. protecting the people and equipment on board.
A lightning strike can mess up some of the electrical systems of the aircraft, though. But no worries. The pilot’s skills and experience come in handy, as he or she has been trained to be able to safely land the plane without being able to utilize all the modern technology. However, all the most crucial flight instruments are duplicated onboard for good measure to make sure that at least one is always working in case something goes wrong.
Why Do Planes Avoid Thunderstorms Then?
If the lightning strike is not hazardous for the aircraft, then why take long and expensive detours to avoid them?
Even though a lightning bolt does not pose a significant risk to the aircraft, the weather conditions in a thunderstorm are unpredictable and dangerous. The violent updrafts in a growing thunderstorm cloud are strong enough to support a human and the hailstones can easily be the size of a golf ball. By no means is any flying thing designed to withstand these weather conditions.
The safety rules simply won’t allow planes to fly through thunder clouds. The storm must be avoided by taking a detour by going around the thunder cloud. It is not allowed to fly below or above the thunder clouds either. This is because the altitude needed to fly over the cloud can be too high. Flying below the cloud obviously exposes the aircraft for lightning strikes, which is not preferred either.
And Even if it was 100% safe and acceptable, the flight experience would be terrible enough for the passengers to start avoiding the airline in question.
