NEXT-GENERATION AIR-TRAFFIC-CONTROL AUTOMATION

The automation of air traffic control (ATC) applications has challenge d the technologies traditionally used for building and testing large d ata processing systems. These systems are characterized by complex app lications, extensive external and user interfaces, and rapidly changin g functional requirements. The Advanced Automation System (AAS) of the Federal Aviation Administration combines high availability, extensibi lity, 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 maint enance, and with the complete trust and confidence of air traffic cont rollers 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 characteri stics and architecture of the AAS and focus on key mechanisms of avail ability and extensibility.