Aviation's Potential Peril: Lightning's Impact on Aircraft
Modern commercial airplanes are designed to withstand the power of lightning, thanks to a combination of conductive materials, specialized devices, and stringent safety measures.
After a lightning strike, even on modern airliners, post-strike inspections are required to find and repair any damage. However, catastrophic outcomes are rare, as modern designs primarily protect passengers and critical systems through their conductive outer skins, acting as Faraday cages. These cages safely channel the lightning's electrical current around the fuselage, preventing it from penetrating inside.
The aircraft’s metal skin distributes and directs the lightning current around the aircraft, a process known as the Faraday cage effect. Small metal protrusions, known as static discharge wicks, fitted across the wings or tail, help dissipate static electricity and serve as controlled exit points for lightning currents, reducing the chance of erratic strikes or damage.
All structural components are electrically bonded to form a continuous circuit, preventing arcing or sparks by allowing current to flow smoothly through the airframe. Protective devices such as braided metal sheathing for sensitive avionics, flame-suppression foam, and inert gas systems (e.g., nitrogen in fuel tanks) reduce the risk of fire or explosion caused by lightning-induced sparks.
Composite aircraft, which are not inherently conductive, incorporate embedded conductive meshes or foils to replicate the Faraday cage effect and conduct lightning safely.
Flight operational procedures also play a crucial role in minimizing the risk of lightning strikes. Pilots rely on weather forecasts and air traffic control to avoid thunderstorms and strong electrical fields that increase the likelihood of a strike.
In the unfortunate event of a lightning strike on the ground, aircraft are often grounded with conductive straps to help reduce the chance of a lightning strike jumping to crew members.
However, incidents like the Flightline Flight 101 crash in 2001 and the LANSA Flight 508 crash in 1971, both suspected to have been due to electrical failures after a lightning strike, highlight the need for continuous improvement in lightning protection systems.
Emerging challenges include protecting newer electrically powered or hybrid aircraft, which have multiple potential strike points and sensitive battery systems. This has prompted the development of holistic lightning protection strategies addressing both structural and electrical vulnerabilities.
In summary, modern commercial airplanes are highly resilient to lightning strikes, preventing damage or crashes related to such natural electrical discharges. The combination of conductive airframe design, specialized devices for current management, flight operational procedures, and stringent certification standards ensures the safety of passengers and crew during these events.
Scientists in the field of environmental science are exploring innovative ways to protect electrically powered or hybrid aircraft from potential damage caused by lightning, given the multiple strike points and sensitive battery systems on these new aircraft.
The development and integration of advanced hardware solutions, such as conductive meshes or foils, into the design of these newer aircraft aim to replicate the Faraday cage effect, ensuring a safe conduction of lightning currents.
