Airport risk assessment: a probabilistic approach L. GUERRA, T. MURINO, E. ROMANO Department of Materials Engineering and Operations Management University of Naples “Federico II” p.le Tecchio – 80125 Napoli ITALY Abstract: Risk reduction is one of the key objectives pursued by transport safety policies. Particularly, the formulation and implementation of transport safety policies needs the systematic assessment of the risks, the specification of residual risk targets and the monitoring of progresses towards those ones. Risk and safety have always been considered critical in civil aviation. The purpose of this paper is to describe and analyse safety aspects in civil airports. An increase in airport capacity usually involves changes to runways layout, route structures and traffic distribution, which in turn effect the risk level around the airport. For these reasons third party risk becomes an important issue in airports development. To avoid subjective interpretations and to increase model accuracy, risk information are colleted and evaluated in a rational and mathematical manner. The method may be used to draw risk contour maps so to provide a guide to local and national authorities, to population who live around the airport, and to airports operators. Key-Words: Risk Management, Risk assessment methodology, Safety Civil aviation. 1 Introduction Risk reduction is one of the key objectives pursued by transport safety policies. Particularly, the formulation and implementation of transport safety policies need the systematic assessment of the risks, the specification of residual risk targets and the monitoring of progresses towards those ones. Furthermore, targeting phase needs a deep analysis to balance efforts, achievability, public and political acceptability of the policies to be implemented [24]. Risk assessment ranges from the interpretation of the available data concerning frequent threats or the estimation of very rare events likelihood: combining these information with the expected loss would result in quantifying the risk exposure index. Risk assessment is an essential process in making policy decisions for risk management. By identifying the nature and scale of the potential impact on consumers or employees, risk assessment can assist regulatory authorities and business organizations to determine what type of action is needed [13]. Risk and safety have always been considered critical in civil aviation [26]. An airport is a multifunction distributed system that is part of a much larger system. You can think of it as being at the centre of a dynamic network made up of all the sources of cargo, passengers and the other people who travel to and from the airport; visitors, cleaners, et alia. But that is just the ground system; a large number of these networks are interconnected to form a huge communications network; the nodes are the airports with their hinterlands, and the dialogues are made up of aircraft [23]. Airports presence causes a convergence of air traffic over the surrounding area so, people who lives in that area are unconsciously exposed to aircraft accidents risk. Actually, local risk levels are higher than might be expected. In fact, even if it is true that the accident per flight index is very low (typically 1 per 10 6 ), statistics demonstrate that accidents mostly happen during take-off and landing phases and hence, close to the airport. Moreover, the low probability of an accident per movement if combined with the high number of flight operations (typically several hundreds of thousands) may suggest the probability of one accident to be higher than we could expect. Risk level around large airports are, in effect, of the same order as those associated with participation in road traffic. An increase in airport capacity usually involves changes to runways layout, route structures and traffic distribution, which in turn effect the risk level around the airport. For these reasons third party risk becomes an important issue in airports development. In the late 1990s the world’s airline fleet consists of more than 15.000 aircraft flying a network of approximately 15 million km and serving nearly 10.000 airports. The sector directly employs more than 3.3 million people, with over 1.4 million in USA [5]. Some 12 billion people and 23 million tonnes of freight are being moved annually. The freight figure represents approximately one third of value of the world’s manufactured exports. A variety of international institutions, organisations and agencies deal with forecasting future trends, including International Civil Aviation Organization (ICAO) and International Air Transport Association (IATA). The airspace manufacturers such as Airbus Industry, Boeing and Rolls Royce also make 10th WSEAS Int. Conf. on AUTOMATIC CONTROL, MODELLING & SIMULATION (ACMOS'08), Istanbul, Turkey, May 27-30, 2008 ISBN: 978-960-6766-63-3 359 ISSN: 1790-5117