ADS-X the Next Gen Approach for the Next Generation Air Transportation System

Global aviation is beginning to deploy and use automated dependent surveillance-broadcast (ADS-B) for surveillance in air traffic control. Air Navigation Service Providers (ANSP) are installing ground stations, experimental procedures and flight trials are beginning, and the Federal Aviation Administration (FAA) is investing over $ 1 Billion in ground infrastructure. The FAA intends to implement rulemaking and by 2014, all aircraft must be equipped with limited ADS-B capabilities to operate in the National Airspace System (NAS). But as we look forward to the next generation air transportation system (NGATS) in the United States and the Single European Sky ATM Research (SESAR) initiatives in Europe, a new generation of ADS-B is necessary. Called ADS-x, the avionics and ground systems are built around the NGATS concepts of network-centric air traffic management, 4D trajectory-based separation, self-spacing, sequencing and separation, and much greater air-to-air integration and use of information. This look into the future is not based on what today\´s technology can do, but what the air transportation system demands by 2025. Dependent surveillance needs to transform to meet these new performance demands. This future leverages continuing successes of required navigation performance, precision positioning, and the concept of control by exception to form the basis of a performance "contract" that allow pilots to use ADS-x and cockpit display of traffic for maintaining aircraft sequencing and spacing built on a 4D trajectory. The ADS-x operational concepts and scenarios presented provide a look forward into the NGATS/SESAR transformation and shares some observations that avionics developers need to consider to 1) assure that existing ADS-B product line offerings can be forward compatible, and 2) that ADS-B is on a transformation path to ADS-x so that initial investments in technology still make sense 15 years from now