The development of probabilistic models to estimate accident risk (due to runway overrun and landing undershoot) applicable to the design and construction of runway safety areas Rosa María Arnaldo Valdés a,b,⇑ , Fernando Gómez Comendador c , Luis Mijares Gordún d , Francisco J. Sáez Nieto b a C/Juan Ignacio Luca de Tena, 14, 28027 Madrid, Spain b Aeronautical Infrastructures, Air and Space Systems and Airports Department, Polytechnic University of Madrid, Plaza Cardenal Cisneros s/n, 28040 Madrid, Spain c INECO, Avda. Partenón, 4 – 4ª planta. Edificio Egeo, Campo de las Naciones, 28042 Madrid, Spain d Senasa, Avenida de la Hispanidad, s/n., Madrid, Spain article info Article history: Received 27 September 2009 Received in revised form 26 July 2010 Accepted 29 September 2010 Available online 28 January 2011 Keywords: Risk management Aircraft landing overrun Aircraft take-off overrun Aircraft landing undershoot Accident probability Runway safety areas Accident wreckage location abstract The risks of landing overrun (LDOR – LanDing OverRun), Take-off Overrun (TOOR – Take-Off OverRun) and landing undershoot (LDUS – LanDing UnderShoot) are dependent on multiple factors related to oper- ating conditions. These include wind, runway surface conditions, landing or take-off distances required, the presence of obstacles, runway distance available, the existence and dimensions of runway safety areas. In this paper we propose risk models for runway overrun and landing undershoot, using a probabilistic approach. These models are supported by historical data on accidents in the area around the runway and will enable us to determine if the risk level is acceptable or whether action must be taken to mitigate such risks at a given airport. Furthermore, these models permit comparison of the results of different risk mit- igation actions in terms of operational risk and safety. The principal advantage of this method is the high quality results obtained for a limited investment in terms of time, computing power and data. As such the method is extremely practical and easy to apply in aerodrome planning, development and operation. Ó 2010 Elsevier Ltd. All rights reserved. 1. Introduction A large number of air accidents occur during the takeoff and landing phases. Most occur beyond the designated safety and pro- tection areas, around the runway, when an aircraft overruns the runway-end during takeoff or landing, or when it undershoots the runway, with regard to the threshold, during landing. The most common accidents that occur during these flight phases are: – Landing overrun (LDOR – LanDing OverRun). – Landing undershoot (LDUS – LandDing UnderShoot). – Take-off overrun (TOOR – Take-Off OverRun). – Ground collision after takeoff. To mitigate the consequences of accidents ICAO (ICAO, 1999) and other organisations, such as the FAA (FAA, 1989), designate, for each type of accident, specific safety areas next to the runway. These standards have evolved over time. As such, their application to existing airports may pose certain problems, particularly when there are ground limitations due to the relief or the pressure of contiguous local populations. Our principal objective was to develop a systematic and practi- cal method which will allow those organisations involved in the design and management of airports to evaluate the risk level of a particular airport where it is not possible to satisfy the standards set for safety areas next to the runway. To develop this method, the following steps were carried out: – Collection of historical data on accidents representative of the study cases considered. – Development of a data model for accident classification and description. – Formalisation of this model in a database. Subsequent exploitation of the database and consultation of dif- ferent literature sources enabled us to identify relevant parameters and factors to understand the circumstances of accidents due to 0925-7535/$ - see front matter Ó 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.ssci.2010.09.020 ⇑ Corresponding author. Tel.: +34 636708530; fax: +34 913367516. E-mail addresses: rosamaria.arnaldo@upm.es (R.M. Arnaldo Valdés), fgomez@i- neco.es (F. Gómez Comendador). Safety Science 49 (2011) 633–650 Contents lists available at ScienceDirect Safety Science journal homepage: www.elsevier.com/locate/ssci