Watching ominous flashes and flashes outside the window as the plane sails through dark, threatening clouds is undoubtedly one of the most psychologically testing experiences for anxious passengers. The question that the mind instantly formulates is terrifying: “What would happen if a million-volt discharge hit the nacelle exactly at this moment?”.
Well, the data will shock you. Do you know that, statistically speaking, the average commercial airliner is struck by lightning about once or twice a year? And despite these numbers, no accidents related to this phenomenon have been recorded thanks to physics principles known for over two centuries. Let's discover the incredible invisible barrier that protects you and your loved ones.
1. The Fundamental Principle: The Faraday Cage
What saves the aircraft and all its passengers is not divine luck, but rather a fundamental concept of the physics of electromagnetism discovered by the British scientist Michael Faraday way back in 1836. The aircraft by its very constructive nature behaves like the most perfect and mammoth Faraday cage.
How electric current travels
The aircraft fuselage is mostly made of aluminum or, in the most cutting-edge carbon composite models, of conductive networks woven with special copper alloy meshes. When lightning makes contact (usually at the nose of the plane or on the tips of the wings), the very high amount of electrical energy from the lightning NEVER penetrates the structure where the seats and crew are located. Instead, electricity flows lightning fast exclusively along the external surface of the metal fuselage, like water sliding off the shell of an umbrella. Passengers sitting inside are at the "zero potential" point, completely isolated and dry under this invisible thermal and electromagnetic safety blanket.
2. "Static Dischargers"
If the current slips on the external armor, where does it go? The aerospace industry has placed microscopic heroes on the wings of the airplane. If you look out the window at the back of the wing, or the giant vertical tail fin, you will notice small thin rods protruding and apparently very faint resembling stiff wires or appendages. Those tiny pins are called Static Dischargers (Static dissipators).
They serve exactly to release electricity into the neutral atmosphere. After traveling at around a million Volts spread harmlessly on the metal back of the plane, the energy is dispersed in the void of the air behind the aircraft through those tips, making sure that the discharge ends its course in the sky, dissipating and splitting without striking a blow.
3. Are the Electronics Not Damaged?
A typical objection raised in forums dedicated to fear of flying concerns the "brains" of the plane. "Even if I don't get electrocuted, what if the lightning burns out all the digital computers in the cockpit causing us to crash due to dead engines?"
Yet another false myth inspired by Hollywood cinema. All the modern on-board avionics boast wiring dozens of centimeters thick, methodically sealed by special and overlapping armored electromagnetic shielding gauze (EM Shielding). Simulators and severe bodies like EASA subject these systems to controlled weathering in laboratory hangars using artificial lightning generators that are immensely more fearsome than the best equatorial thunderstorm! The result is that not a single blackout of the primary instrumentation will be able to occur under adverse atmospheric influence, otherwise during the patenting phase the aircraft would not come off the assembly line and be launched on the rental market to operators. Flying is the most exact and rigorous science on the globe.