Flight Demonstration of the Separation Analysis Methodology for Continuous Descent Arrival

The Tool for the Analysis of Separation And Throughput (TASAT) has been developed to predict the trajectories of different aircraft performing a given continuous descent arrival (CDA) and thereby determine the minimum spacing at a metering point such that there is a high probability of no separation violations during the remainder of the procedure. The resulting reduced need for controller intervention is expected to facilitate the implementation of CDA. This tool includes a fast-time Monte Carlo aircraft trajectory simulation environment and a theoretically rigorous separation analysis methodology based on probabilistic characteristics of aircraft trajectory variations. The tool was used to determine the target spacing between aircraft at the metering point for the Area Navigation based Continuous Descent Arrival flight test project conducted in September 2004 at Louisville International Airport. The flight test results indicated that the determined 15 nm target spacing yielded conditional probabilities of 69.6% for CDA to runway 35L, which is very close to the predicted value of 68.6%. The flight test also indicated an overall total probability of 81.7%, which is between the predicted overall total probabilities of 79.6% and 85.0% for the CDA to runway 35L and 17R respectively. The flight test demonstrated that with the tool developed, Continuous Descent Arrival can be efficiently implemented under moderate to moderately high traffic conditions to achieve environmental and economical benefits.