When an aircraft encounters a lightning strike, it is a common event that rarely poses significant danger. Commercial transport planes are typically struck once or twice a year, or approximately every 1,000 flight hours. Modern aircraft are specifically engineered to safely manage these occurrences. This advanced design ensures the safety of passengers and crew, making such incidents more startling than hazardous.
The Lightning Path
When lightning strikes an aircraft, it typically begins at an initial attachment point, often an extremity like the nose, wingtip, or tail. The electrical current then travels along the plane’s conductive outer shell.
This movement of current across the exterior is known as the “skin effect.” The electrical charge flows over the aircraft’s surface rather than penetrating the interior, protecting occupants and sensitive internal systems. The lightning typically exits from another extremity of the aircraft, such as a wingtip or the tail. This entire process occurs rapidly, with the high-voltage current passing over the aircraft in a fraction of a second.
Aircraft Protection Systems
Aircraft are designed with sophisticated protection systems to safely manage lightning strikes. A primary defense is the “Faraday cage” effect, where the plane’s conductive outer shell channels electrical current around the cabin and critical components. This design prevents the electrical charge from entering the interior, shielding passengers and electronics.
Static wicks, or static dischargers, are small, pointed devices on the trailing edges of wings and tail surfaces. While their main function is to dissipate static electricity, they also help manage current flow during a lightning strike by providing controlled exit points. Critical components like fuel tanks, wiring, and avionics are shielded and reinforced to prevent ignition or damage from electrical surges. Systems are also designed with redundancy, meaning backup systems are in place to ensure continued operation even if one is affected.
Experience and Immediate Aftermath
Passengers and crew typically experience a lightning strike as a bright flash of light, often accompanied by a loud bang. Cabin lights might flicker momentarily, and some passengers report a slight shake or jolt. While startling, the experience is more dramatic than dangerous, thanks to the aircraft’s protective engineering.
Immediately after a suspected lightning strike, the flight crew follows established checklists. They check all instruments and systems to ensure everything is functioning normally. Pilots are trained to assess the situation and, if necessary, may divert the flight for further inspection. Modern aircraft systems are built with multiple layers of protection and redundancy, reducing the likelihood of critical system failures.
Post-Strike Procedures and Safety
After an aircraft has been struck by lightning and lands, it undergoes a mandatory inspection. Ground crews visually inspect the entire surface for physical damage, such as small burn marks, pitting, or melt marks, particularly at the entry and exit points. While minor cosmetic damage is possible, significant structural damage is rare.
The inspection is thorough and time-consuming, sometimes requiring the aircraft to be grounded for several hours to ensure airworthiness. This detailed examination ensures that any potential issues are identified and addressed before the aircraft returns to service. Modern commercial aircraft are designed to withstand multiple lightning strikes over their operational lifetime, reinforcing the aviation industry’s impressive safety record.