Modeling the Impact of Equipment Outages o n National Airspace System Operations

This study is a part of a larger effor t initiated by the FAA’s System Capacity Office, Capacity Initiative Division , towards developing a methodology for assessing airport performance and establishing airport efficiency metrics for runway and airport utilization. The study links several datab ases to provide better understanding of airport and runway operations during equipment outages. A methodology is proposed for modeling and analysis of airport and airspace operations during unscheduled equipment outages by first analyzing aircraft headway s. Unscheduled equipment outages impact operations of the National Airspace System (NAS) on a daily basis by causing airport throughput reductions, delays or flight cancellations and therefore the impact of such outages has to be further reduced, and bett er monitored and understood . The part of the methodology discussed in this paper statistically analyzes landing time intervals to find operational properties of an airport using the Performance Data Analysis and Reporting System (PDARS) database. T he PDARS database allows the calculation of landing time intervals on a runway level. We propose, explore and construct new mathematical model s to fit the distribution of the landing time intervals and compare new maximum log likelihood estimations to t he existing models. The proposed model presented in this study better approximates the shape of the probability distribution, especially the left -hand side. The left side usually contains information of greater importance regarding airport operations and especially regarding safety, since all smaller landing time intervals, and the landing intervals that fail the safety requirements, are concentrated in this part of the probability distribution curve.