A new determination of air crash frequencies and its implications for operation permissions

摘要

The crash frequency is dominated by the military aircrafts (65%), though their crash frequency decreased by 82,5% since the 1980's. However the influence of the civil airplanes is no longer negligible. Especially aircrafts with less than 20 tons contribute a proportion of 22% to the entire crash frequency. Taking into consideration that only 10% of these aircrafts have more than 2 tons takeoff weight, the potential hazard of this machines is negligible small. The fact that the often used value for air crash frequency in /2/ has the wrong order, has no impact on the operation of the plant in this case. For other sites an extra determination should be made. Due to the decrease of the air crash frequency of military aircrafts both, the total number of air crashes decreased about 73% from the 1980's and the potential of hazard decreased even more, because the crash of military aircrafts is considered as a worst case scenario.