 |
 |
 |
 |
| |
|||||
|
|
|
Home > News & Events > MITRE Publications > The MITRE Digest > | |||||||||||||||||||
| URET: Air Traffic Control System Reaches Operational Milestone July 2001
Until recently, the 800 air traffic controllers at the Indianapolis and Memphis Air Route Traffic Control Centers relied on a fairly limited set of tools to manage flight data and predict conflicting flight paths. But today, as a result of close collaboration between the Centers and MITRE's Center for Advanced Aviation System Development (CAASD), a new decision-support system, the User Request Evaluation Tool (URET), is available for controllers at both sites. On May 6, URET passed its one millionth hour of operational use. This milestone, which represents the successful culmination of many, many hours of research and development in CAASD labs and in the field, is significant: the use of URET will increase the efficiency and safety of the National Airspace System (NAS), two of the Federal Aviation Administration's (FAA) long-term goals. For the 15,000 flights passing through Indianapolis and Memphis airspace daily, the URET prototype provides highly accurate and timely information that helps controllers and pilots meet growing demands for more flexible and more efficient operations. URET Capabilities URET combines real-time flight plan and radar track data with information on ground conditions, aircraft performance characteristics, and winds and temperatures aloft, to construct four-dimensional flight profiles, or trajectories. For active flights, it also adapts itself to the observed behavior of the aircraft, dynamically adjusting predicted speeds, climb rates, and descent rates based on the performance of each individual flight as it is tracked en route. URET regularly updates aircraft trajectories to get a highly accurate prediction of future aircraft positions. URET uses its trajectories to continuously detect potential aircraft conflicts up to 20 minutes into the future and to notify the appropriate sector. Trajectories are also used for trial planning, which allows the controller to check a pilot's desired flight plan before issuing a clearance. The controller can then construct an amended flight plan that resolves conflicts in the trial plan with the click of a button. The system has an auto-coordination feature, which coordinates plans among sectors and air traffic control facilities. The controller sees both text and graphic displays. The text-based Aircraft List and Plans Display helps manage current flight plan information, trial plan information, and conflict data. The Graphic Plan Display provides a view of aircraft routes and altitudes, detected conflicts, and results of trial planning. The point-and-click interface enables quick access to system functions and entry of flight plan amendments. A key part of the URET infrastructure is its interfacility, or IFA, capability. In IFA operational mode, URET systems in neighboring en route air traffic control facilities exchange critical flight and track data. This data sharing significantly improves the quality of the information used by each system, thereby reducing uncertainties in its predictions and improving overall controller situational awareness. URET Benefits In many cases, particularly in the congested airspace of the Northeast and the Midwest, aircraft fly according to rigid route and altitude restrictions. These restrictions have some very positive aspects: they increase predictability in traffic patterns, and ease workload and coordination among controllers. However, they also reduce flexibility and efficiency. With URET, controllers have real-time help in the early detection and resolution of aircraft conflicts—encounters where two aircraft come too close. URET provides two major benefits. First, controllers are notified of aircraft conflicts up to 20 minutes in advance (in contrast to facilities without URET where 2-3 minutes' advance notice is the norm). And second, controllers have trial planning capabilities for testing potential resolution strategies before issuing a clearance to the pilot. This assistance dramatically reduces the need for route and altitude restrictions. As a result, the URET capabilities have significant economic advantages. Estimates from Indianapolis and Memphis Centers show annual cost savings of approximately $10 million just from the more direct routes that airlines fly through those facilities. For controllers, URET dramatically improves the quality and timeliness of information available at each sector, so controllers can do more strategic traffic planning. For the aviation community, URET enables more flexible, efficient operations with reduced restrictions and more collaborative decision making between pilots and controllers. For the flying public, URET promotes safer air travel with accurate, reliable, and timely detection of potential conflicts. MITRE/CAASD's Pioneering Research URET technology is rooted in the Automated En Route Air Traffic Control, or AERA, concept, which began in the 1970s and was formulated over many years of research at MITRE/CAASD's labs in McLean, Va. In January 1996, an initial URET prototype was installed at Indianapolis. A year later, another prototype was installed at Memphis to evaluate its ability to exchange information with other air traffic control facilities. Since late 1997, URET has been in Daily Use configuration at both facilities. Today, it is operational at about 40 sectors in each facility, 22 hours a day, seven days a week. Daily Use operations have provided a wealth of feedback from controllers, which has driven the evolution of the system to its present form. A New Approach With more than one million operational hours under its belt, URET has already yielded substantial benefits. Equally important, it has helped researchers establish a new way of doing business, both in terms of how air traffic control is conducted at en route sectors, and how organizations such as the FAA and MITRE/CAASD introduce new technologies into that environment. Elements contributing to its success include: End-User Involvement. The extent to which air traffic controllers have been involved in identifying operational needs, refining concepts, validating system performance and benefits, and developing procedures is unprecedented. Daily Use operations, in particular, have provided a rich environment for getting feedback and driving the evolution of the system. Collaboration with the Aviation Community. As part of Free Flight, the FAA has expended a good deal of energy in ensuring that the aviation community is deeply involved in paving the way for URET's fielding. This community plays a critical role in developing a shared vision for success and in evolving the requisite capabilities to achieve it. Transitioning Technology to Industry. The transition of URET technologies from government to industry continues to be highly successful. This process facilitated using assets developed by CAASD—from high-level requirements to software code—as well as continued collaboration with MITRE staff who can combine their knowledge of air traffic operations with sound engineering and systems analysis principles. Looking to the Future As controllers know only too well, the increased demands on air traffic services are not unique to Indianapolis and Memphis Centers, but part of a national problem facing the FAA and the entire aviation community. The system must accommodate more airplanes; passengers and airlines want fewer delays; and controllers need better tools to handle the increasing—and increasingly complex—traffic without compromising safety. One way in which the FAA is facing this daunting challenge is by bringing the URET capabilities prototyped in Indianapolis and Memphis to more en route facilities nationwide. Lockheed Martin is developing a production version of URET that will be deployed to five additional sites under the FAA's Free Flight Phase 1 program by 2002. Those associated with today's URET, as well as those who did the pioneering AERA research, have every reason to be proud of the improvements URET brings to the NAS today. They can be proud, too, of enhancements that will make these capabilities even better in the future.
Page last updated: August 23, 2001 | Top of page |
Solutions That Make a Difference.® |
|
|
