7. Conclusions

The circumstances and consequences of an aircraft being struck by lightning are now well understood, even if the natural phenomenon still holds a few secrets that scientists are still working on. All it takes is for an aircraft to approach a thundercloud, in an area where the atmospheric electric field is sufficiently intense, for lightning to develop, usually triggered by the aircraft itself. Many frequent flyers, intensive users of air transport, have experienced an in-flight lightning strike whose minimal consequences, accompanied by reassuring comments from the crew, left them unconcerned. We have seen, however, that the safety provided by lightning protection is the result of taking lightning into account at every stage of aircraft design. Lightning certification consists in "hardening" the aircraft, its engines and all its systems against a lightning strike of a majorant level, which...