Next generation air traffic control automation

The automation of air traffic control (ATC) applications has challenged the technologies traditionally used for building and testing large data processing systems. These systems are characterized by complex applications, extensive external and user interfaces, and rapidly changing functional requirements. The Advanced Automation System (AAS) of the Federal Aviation Administration combines high availability, extensibility, and extraordinary functionality into a single distributed system, running at multiple locations. By requirement, the AAS must execute continuously without error, without interruption for upgrades or maintenance, and with the complete trust and confidence of air traffic controllers using it at over twenty centers. Each ATC center uses the same application software coupled with varying quantities of hardware and an extensive base of data to tailor the center to its unique geography and operational procedures. In this paper, we describe the characteristics and architecture of the AAS and focus on key mechanisms of availability and extensibility.