If you are a frequent flyer, you already know this. Suddenly, the cabin goes quiet, and you see a blinding flash of lightning. Sometimes there is even a crack so loud that you white-knuckle the armrest. As the anxiousness is visible on the passengers’ faces, the flight attendants exchange those familiar glances. A lightning strike at 30,000 feet is quite different from how you see it from your home. So, can lightning strike an airplane? The answer is yes. It can strike. Regularly. Commercial jet airliners in the US are struck by lightning once every 1,000 flight hours, or once each year on average, according to the National Weather Service. That’s not a rarity. Now, does that mean you should be worried? Not really. Planes that are hit by lightning still land safely.
When lightning strikes
If you are concerned about lightning striking airplanes, you should know this surprising fact: aircraft often trigger lightning when flying through a heavily charged region of a cloud. In such conditions, the aircraft itself becomes a conductive pathway within a developing electrical discharge. The best part is that planes are engineered to deal with it, with systems that carry the lightning safely along the outside. Lightning mostly strikes at near-freezing temperatures, during turbulence, and around 60% of all lightning strikes occur from March to July.When lightning connects, it follows a specific journey through the aircraft. Initially, it strikes a sharp edge, such as the wingtip or nose. The airplane then flies through the lightning flash, which reattaches itself to the fuselage at other locations while the aircraft is in the electric ‘circuit’ between cloud regions of opposite polarity. The current travels through the plane’s conductive exterior and structures and exits via the tail. Lightning does not randomly damage the plane. Instead, it follows the path of least resistance, exactly the one engineers planned for. The electricity passes along the outside of the plane, and any damage is usually limited to tiny marks or small holes. According to the NWS, a mandatory inspection for damage is carried out when it is suspected that a plane has been hit by lightning. This is an expensive affair and can also cause flight delays. For this reason, and because of turbulence, pilots avoid thunderstorms as much as possible. However, not all planes are designed in the same way. Small private and experimental aircraft are not designed for protection from lightning.
Is it safe, though?
The honest answer is yes. There has not been a lightning-caused commercial transport airplane crash in many decades, according to the NWS. Lightning strikes are classified into two types: direct and indirect. When lightning hits an aircraft directly, it usually causes very little impact on the aircraft and no effect on passengers. “Passenger planes are designed to mimic a Faraday cage, which acts as a receptor to absorb the electricity,” Daniel Bubb, PhD, a former pilot and the author of Landing in Las Vegas: Commercial Aviation and the Making of a Tourist City, told Reader’s Digest.Passengers and crew may see a flash and hear a loud noise if lightning strikes their plane; nothing serious should happen because of the careful lightning protection engineered into the aircraft and its sensitive components. You are statistically safer experiencing a lightning strike at cruising altitude than driving on a highway during a thunderstorm. One is engineered for it, and the other is not.Rarely do lightning strikes on airplanes cause catastrophic effects. According to Bubb, in rare cases, electricity from lightning can interfere with avionics and instruments. “That would prevent the pilots from being able to talk to air-traffic controllers and use certain cockpit systems,” he said.And what about the airplane going into flames when lightning strikes? “I think the biggest misconception people have about airplanes that get hit by lightning is that they will explode, or the engines will fail, and the airplane will fall out of the sky,” he said. “I attribute part of this to Hollywood films. The likelihood of that happening is zero.”So, the next time you witness lightning illuminating your cabin, maybe take it easy. Know that your aircraft is protected against it and prepared for it. The flash is real. The danger, by design, is not.
