Flight-Test Evaluation of the Tool for Analysis of Separation and Throughput

The tool for analysis of separation and throughput has been developed to predict the range of possible trajectories of aircraft performing any given continuous descent arrival and thereby determine the minimum target spacing at a metering point, such that there is a high probability of no separation violations thereafter. The resulting reduced need for controller intervention is expected to facilitate the implementation of continuous descent arrival. This tool includes a fast-time Monte Carlo trajectory simulator and a theoretically rigorous separation analysis methodology based on the probabilistic characteristics of trajectories. The tool was used to determine the target spacing for a continuous descent arrival flight test conducted in September 2004 at Louisville International Airport. Results of the flight test indicate that the 15-n-mile target spacing yielded a conditional probability of 69.6% for the continuous descent arrival to runway 35L, very close to the predicted value of 68.6%; and an overall total probability of 81.7%, which is between the predicted values of 79.6% and 85.0 % for the continuous descent arrival to runway 35L and 17R, respectively. The flight test demonstrated that, by using the tool as developed, continuous descent arrival can be efficiently implemented under moderate to moderately high traffic conditions, thereby achieving much needed environmental and economic benefits.