An integrated safety-analysis methodology for emerging air-transport technologies

We demonstrate an approach to integrating reliability, performance, and operational procedures modeling into a system safety analysis. Our methodology is distinguished by its ability to merge system design information with the dynamic parameterization of a system's situation in order to measure accident statistics and reliable system operation. As an application of this methodology, we have considered the problem of simultaneous, but independent approaches of two aircraft on closely-spaced parallel runways, Independent Approaches on Parallel Runways, or IAPR. The IAPR concept presumes a flight deck based navigation, communication, surveillance, and alerting system. The potential exists for an aircraft on either runway to deviate off course toward another aircraft on the parallel runway. A variety of simulation projects have been undertaken to explore alerting systems for the parallel approach situation, but the major limitation of statistical information generated from these studies is that it represents conditional safety statistics given the flight track simulated. To remove this conditioning, we have shown how to apply the probability of flying the approach with a given flight track using Markov analysis to compute this probability. The results show how each of the probabilities of reliable operation, accidents, and false alarms vary as a function of runway spacing.