Airport veer-off risk assessment: An italian case study

The objective of this paper is to assess the veer-off risk of an Italian airport that is characterized for having near 12,000 annual movements. The name of this airport is not disclosed for security purposes. The methodology used followed the principles of probabilistic risk analysis in order to characterize the events and assess the corresponding damages. The study used statistical data about accident reports and local conditions that were collected following the standards of the International Civil Aviation Organization (ICAO). The methodology used in this work complies with the guidelines for the adjustment of lateral runway strips, edited by the Italian Civil Aviation Authority (ENAC). Besides, data available in worldwide databases of airplane accidents were also gathered and included as part of the analysis. The method used to assess the veer-off risk of the airport is consistent with probability and damage quantification methods published in the literature. The main variables considered in the analysis were traffic information, wind conditions, the existence of landsidebuildings adjacent to the runway, and the geotechnical conditions of the subgrade underneath the strip zones. For the assessment of the veer-off risk, the authors used primary data provided by the airport management body within the period 2013-2015 and secondary data available in the literature. The risk of veer-off was calculated in more than 1,500 points around the runway. Besides, the authors proposed maximum allowable risks in different locations, and these values were compared to the actual risk levels previously computed. The results of this comparison suggested that improvements in the soil capacity and/or in the airport management activities might contribute to achieve the proposed allowable risk. The results from this assessment showed that the two critical variables determining the risk of veer-off accidents in the airport under evaluation were wind conditions and the bearing capacity of the soil underneath the strip areas. Also, it was found that the highest veer-off risk level obtained within the Cleared and Graded Area (CGA, part of the runway strip cleared of all obstacles and graded) was 2 10-7, while the lowest level was 3 10-8, which are considered typical risk ranges in airport operations. In general, the results demonstrate that the adopted methodology is a useful tool to evaluate the veer-off risk of a specific airport. Besides, the method allows comparing the actual levels of risk with proposed target levels of safety.Consequently, the quantification of the veer-off risk levels offers the airport management body the possibility of implementing appropriate measurements in those cases where minimum safety requirements are not achieved.