Relative Risk Quantification by Monte Carlo Methods of New Operational Concepts for Approach and Departure Operations

The activities presented in this chapter are aimed at providing an approach for quantitatively evaluating, within a reasonably reduced timeframe, the conservatism of the safety margins in approach and departure operations. The ultimate goal of the proposed approach is to enable eventually more accurate risk-assessment analysis with a higher level of confidence that safety margins can be reduced, and thus that the significant effort required for assessing the risk will not be lost. The proposed methodology relaxes the standard risk-assessment problem up to the point in which simulation-based methodologies, most notably Monte Carlo analysis, can be used for the risk assessment. The approach feasibility is evaluated by devising a fictitious benchmark application case, concerning simultaneous operations of intersecting runways for departing and arriving flights. In this benchmark case, the Monte Carlo technique has been applied to a limited number of critical situations in which some hazardous events have occurred. Three mathematical models have been also developed for describing the aircraft relative dynamics and timing in these scenarios, which integrate various models proposed in the open literature for simulating arrival and departure operations. Application on the benchmark case demonstrates the ability of the proposed approach in providing quantitative information on the conservativeness of actual safety margins, and thus to drive refinement strategies of novel, more efficient, procedures which can be potentially compliant with a required Target Level of Safety