Method for inspecting the structural damage on the skin of an aircraft after a lightning strike, the skin comprising a set of marks derived from the lightning strike, said marks comprising a Visual Damage wherein the paint of the skin has been removed off and a Structural Damage, wherein the aircraft is divided into different zones regarding the probability of receiving a lightning strike having every zone a maximum expected level of energy of the lightning strike, characterised in that the method comprises the following steps: - in every mark, measuring the area of paint that has been removed or scrapped off by the lightning strike, - comparing the measured area with an area threshold value, wherein the threshold value is related to the Structural Damage of every mark and is obtained by the following steps: ∘ sorting empirical data of Structural Damage versus Visual Damage for different levels of energy or peak currents of the lightning strike, the levels of energy or peak currents being below a maximum energy or peak current expectable in the specific aircraft zone in which the mark is located, ∘ providing an admissible Structural Damage for the aircraft zone in which the mark is located, ∘ calculating an admissible Visual Damage (VD ADL) for which the maximum Structural Damage that can be encountered is less than the admissible Structural Damage for the aircraft zone in which the mark is located, said admissible Visual Damage (VD ADL) being the area threshold value, characterized in that if the Structural Damage for the maximum expected level of energy or peak current of the lightning strike in the aircraft zone in which the mark is located is less than the admissible Structural Damage, the maximum energy level expected at the aircraft zone in which the mark is located is taken for calculating said admissible Visual Damage (VD ADL) in the preceding method step. - in every mark, measuring the area of paint that has been removed or scrapped off by the lightning strike, - comparing the measured area with an area threshold value, wherein the threshold value is related to the Structural Damage of every mark and is obtained by the following steps: ∘ sorting empirical data of Structural Damage versus Visual Damage for different levels of energy or peak currents of the lightning strike, the levels of energy or peak currents being below a maximum energy or peak current expectable in the specific aircraft zone in which the mark is located, ∘ providing an admissible Structural Damage for the aircraft zone in which the mark is located, ∘ calculating an admissible Visual Damage (VD ADL) for which the maximum Structural Damage that can be encountered is less than the admissible Structural Damage for the aircraft zone in which the mark is located, said admissible Visual Damage (VD ADL) being the area threshold value, ∘ sorting empirical data of Structural Damage versus Visual Damage for different levels of energy or peak currents of the lightning strike, the levels of energy or peak currents being below a maximum energy or peak current expectable in the specific aircraft zone in which the mark is located, ∘ providing an admissible Structural Damage for the aircraft zone in which the mark is located, ∘ calculating an admissible Visual Damage (VD ADL) for which the maximum Structural Damage that can be encountered is less than the admissible Structural Damage for the aircraft zone in which the mark is located, said admissible Visual Damage (VD ADL) being the area threshold value,