Closely Spaced Parallel Approaches in Terminal Airspace

As the amount of U.S. air traffic continues to grow, the capacity limitations of major airports threaten the efficiency of the national airspace system (NAS). Runways and wake vortex avoidance procedures represent the primary capacity constraints for terminal area operations. The Raytheon Company is developing the terminal area capacity enhancement concept (TACEC) in an effort to increase the capacities of select airports. The TACEC system allows multiple commercial aircraft to fly in close formation during final approach and land on very closely spaced parallel runways via autopilot. The student design team at George Mason University has developed alternative system architectures for TACEC, based on the local area augmentation system (LAAS), wide area augmentation system (WAAS), and instrument landing system (ILS). This paper discusses these system architectures and analyses performed in order to evaluate them. Knowledge of operational environments is critical to the evaluation of physical architectures, however, little is known about the frequencies of Category I, II, and III weather conditions at major U.S. airports. Data from the national weather service aviation climatology assessment has been used to develop ceiling and visibility frequency models for TACEC designated airports. Data obtained from the weather condition frequency models, information regarding operational limitations of navigation subsystems, and cost estimates have been used to perform trade-off analysis of physical architecture alternatives. Additionally, simulations incorporating navigation subsystem accuracy and flight dynamics have been developed to evaluate the safety of alternative functional and physical architectures for TACEC. This paper presents the results of the system architecture evaluations performed by the George Mason University student design team supporting the TACEC project