A number of major airports/terminal areas already experience very high delays during adverse terminal weather. The FAA Administrator's task force has projected a major increase in delays relative to the present delays by the year 2005 if the traffic growth apparent for the past three years continues. The current weather decision support system architecture has not explicitly addressed the problems of improving the effective capacity of major terminal areas during adverse weather. Additionally, there is an urgent need to develop new aviation weather products to support the needs of these terminals.
Over the past four years, tests have been conducted at a number of major airports using a functional prototype Integrated Terminal Weather System (ITWS). The ITWS acquires data from the various FAA and NWS sensors and combines these with products from other systems (e.g., NEXRAD and the NMC Rapid Update Cycle) to generate a new set of safety and planning/capacity improvement weather products for the terminal area and adjacent enroute airspace. Operational users of the ITWS products to date include pilots, controllers, TRACON supervisors, terminal and enroute traffic flow managers, airlines, Flight Service Stations, and terminal automation systems [e.g., the Center Tracon Advisory System (CTAS)].
A key focus of the ITWS functional prototype operational usage has been the assessment of its capability to achieve significant delay reduction and the identification of missed opportunities, wherein further delay reduction may be possible. Testing at Dallas-Fort Worth (the U.S. airport with the highest number of operations in 1997) since 1995 has identified major new benefits of the ITWS during non thunderstorm conditions as well as provided experience in extending product coverage by mosaicing multiple TDWR and ASR-9 radars. The operational usage by the Jacksonville Center (ZJX) has demonstrated the critical importance of improved performance in the transition enroute airspace that surrounds a major terminal if delays attributed to the major airports are to be addressed.
Based on this operational experience at several major terminals, we recommend some significant changes to the U.S. weather system architecture and product mix:
(1) The "transitional" enroute airspace that surrounds major terminals (e.g., out to approximately 100 nm from the terminal boundary) needs to be treated as a very different entity in terms of weather products and display capability than the "overflight" portion of enroute airspace. In many cases, this airspace has a high density of terminal and enroute sensors that can be mosaiced effectively to provide a much higher quality of weather information than is possible for enroute airspace well away from major terminals.
(2) Major terminals need to be treated as a set of "special cases" where special weather sensors may be deployed to meet the site-specific meteorological and operational needs. The Integrated Terminal Weather System (ITWS) architecture needs to be extended to be able to deal with these "special cases" in a cost-effective manner. Special cooperative agreements between the FAA and the airport authorities (as has been accomplished at New York City) may be necessary to develop a weather information system that will address the significantly different challenges posed by the relatively small number of major terminals that cause most of the delays.
(3) Weather product research and development needs to include the possibility of deploying special sensors to address the unique problems of certain transitional airspace/terminal areas as an important aspect of product development rather than being restricted by today's implicit assumption that all of the terminal areas will have the same minimal sensor mix.
Examples drawn from operational experiences with the ITWS prototypes will be provided to support the above recommendations.
* This work was sponsored by the Federal Aviation Administration. The views expressed are those of the authors and do not reflect the official policy or position of the U.S. Government.
+ Opinions, interpretations, conclusions and recommendations
are those of the authors and are not necessarily endorsed by the United
States Air Force
The 8th Conference on Aviation, Range, and Aerospace Meteorology