An aircraft is hit by lightning once a year, in average. A plane flying up to around 20 kilometres (12 NM) from a thunderstorm may still be struck by lightning. Fortunately, the consequences of such an impact are minor, thanks to the Faraday shield effect of the aircraft. The energy of the lightning is distributed on the whole aircraft structure. The passengers are protected. However, the crew may be blinded a few seconds because of the flash. It may happen that a lightning strike lead to minor damage on the aircraft structure, such as delamination of composite materials.