Analyzing the bearing capacity of materials used in arresting systems as a suitable risk mitigation strategy for runway excursions in landlocked aerodromes

Runway-related incidents/accidents based on aircraft operations can be categorized as incursions and excursions. Among all excursion events, landing and take-off overruns are responsible for the major portions. In fact, safety efforts are persistently needed by discovering these types of events, assessing the consequent risks and developing befitting mitigation strategies. There are numerous mitigation strategies to reduce the severity of consequences of runway overrun events. One of the most common strategies is to expand the geometry of the Runway End Safety Area (RESA), which is effective but beside the fact that it is noticeably expensive, many airports are landlocked, and it is difficult to expand their lands. On the other hand, Engineered Materials Arresting Systems (EMAS), as precast blocks or cast in situ slabs, are emerging as a possible interesting solution. Although this is not a new-discovered solution, many aspects are still unknown and are needed to be studied. Therefore, this paper reports the achievements of a study in which a numerical code was developed to simulate the behavior of EMAS materials and evaluate their bearing capacity and efficiency in reducing the aircraft braking distance in case of runway overrun. Thanks to this numerical code, it is possible to achieve not only the exact aircraft stopping location, but also the critical drag and uplift forces acting on the aircraft main gear and the deceleration rate (tire-material interface) after striking the arresting blocks. Additional outcome is a risk contour map overlapped on the EMAS layout that assigns the probability of aircraft stoppage location to the related coordinates on the arrestor bed. In order to discover an appropriate EMAS material with enough bearing capacity, low-density concrete with different natural, mineral and synthetic additives were considered in the evaluations. Boeing B747-8 aircraft was selected as the case study in all the computations.