An Airbus A350 was struck by lightning while sitting on the runway in the midst of an intense storm in São Paulo on Friday. Passengers waiting to board the flight stood and watched as the enormous bolt of electricity hit the tail of the British Airways plane before it was ready to depart.
The BA flight was parked up at São Paulo airport last week when a storm brought strong winds, heavy rain and lightning to the airport. The intense weather grounded planes and delayed dozens of flights, including BA246 from Brazil to the UK.
While the plane was waiting on the tarmac at São Paulo, the tail of the Airbus A350 aircraft was struck by an enormous bolt of lightning, reports Sky News. The moment was captured by passengers waiting to board the very same plane and was shared on social media over the weekend.
The lightning strike didn’t leave the plane in tatters, however, and passengers soon boarded that very same aircraft for an 11-hour flight to London’s Heathrow airport. In fact, the plane was pretty much unscathed by the ordeal, as passenger jets are designed to deal with lightning strikes.
Airplane lightning strikes are actually quite common. Nearly every plane in every fleet has been struck by lightning, on average American fleets experience a lightning strike once every six months. In order to prevent them falling from the sky or sustaining damage when this happens, planes are designed with safety measures in place, as Scientific American explains:
Although 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. Initially, the lightning will attach to an extremity such as the nose or wing tip. The airplane then flies through the lightning flash, which reattaches itself to the fuselage at other locations while the airplane is in the electric “circuit” between the cloud regions of opposite polarity. The current will travel through the conductive exterior skin and structures of the aircraft and exit off some other extremity, such as the tail. Pilots occasionally report temporary flickering of lights or short-lived interference with instruments.
So not only do planes get hit by lighting, but they actually fly right through the bolt when it happens. To protect the exterior of the plane when this occurs, aircraft are made to be super conductive so that the energy from the lightning stays on the exterior of the plane. On aluminum planes that’s easily done, as the metal is a good conductor, while carbon fiber planes often have a layer of conductive fibers embedded on the surface for this very purpose.
The other risky area that needs protecting is the plane’s fuel tanks, as a single spark around one of those could spell disaster. Thankfully, designers carry out thorough tests to ensure onboard fuel tanks are lighting-proof, as Scientific American adds:
Engineers thus take extreme precautions to ensure that lightning currents cannot cause sparks in any portion of an aircraft’s fuel system. The aircraft skin around the fuel tanks must be thick enough to withstand a burn through. All of the structural joints and fasteners must be tightly designed to prevent sparks, because lightning current passes from one section to another. Access doors, fuel filler caps and any vents must be designed and tested to withstand lightning.
To protect the people and their electronics inside a plane when it’s hit by lightning, special insulation, surge suppression systems and grounding are used. These systems prevent the bolt from causing a power surge, which could damage onboard equipment, entertainment systems or anything you’re charging with an onboard power outlet.
All these systems work together and have so far meant that it’s been almost 60 years since a plane was brought down by a lightning strike.