on the performance capabilities of current air transport aircraft, that allow simultaneous, independent, parallel approaches to closely spaced runways in low visibility conditions.

  • Reduce the impact of aviation on local communities. Operational concepts for NGATS should be designed to improve operational efficiency while reducing community impacts (noise and emissions). For example, trajectory-based flight operations would, among other things, allow continuous descents and eliminate the need for adding power to level off during approaches. This would reduce emissions, fuel consumption, community noise, and travel time. Continuous descent approaches would also minimize level flight at low altitudes, which produces more noise and requires a higher thrust setting than descending flight. Continuous descent approaches also keep aircraft at higher altitudes during most of the approach to landing, which increases noise attenuation (NASA, 2004).

  • Increase the productivity of air traffic controllers. Another guideline might establish the principle that new technologies, systems, and procedures will increase capacity by increasing the productivity of controllers (rather than rely on a business-as-usual approach that strives to double or triple the capacity of the air transportation system by doubling or tripling the number of controllers). For example, one way to increase the productivity of controllers in crowded airspace would be to have controllers monitor the placement of an aircraft route “tube” between two cities or waypoints, while relying on aircraft to self-separate within the tube.

Whatever approach is ultimately used to define and assess operational concepts—and the operational roles that human beings should play—it should focus on the area of greatest importance to the future of the air transportation system, which is satisfying increased demand, while also satisfying enabling, interrelated requirements regarding safety, security, environmental effects, consumer satisfaction, and industrial competitiveness.

The operational concepts developed by the IPTs will help sharpen the focus of the entire effort by clearly defining the end state toward which all other investments in research, development, facilities, equipment, procedures, etc., should be directed, in both the short and long term. It is still too early to know what the air transportation system of 2025 will look like in detail, in part because it is impossible to anticipate with certainty the impact of anomalous changes in the world, such as the rise of computer technology over the last 30 years, the rise of the Internet over the past 15 years, or the rise of international terrorism over the last 5 years. However, much information about the air transportation system of 2025 can be deduced from (1) current knowledge about those elements of the existing system that are expected to still be in place, (2) knowledge of short-term improvements that are being or soon will be implemented, and (3) analysis of future operational concepts.

Finding 3-1. Operational Concepts. The Integrated Plan implies that it will develop separate operational concepts for security operations, safety assurance, airport operations, aircraft operations, and ATM operations. Safety and security are inherent in the execution of the latter three, and operational concepts that integrate safety and security considerations from the beginning are more likely to satisfy system requirements than concepts that have safety and security imposed later in the development process.

Recommendation 3-1. Operational Concepts. The JPDO should define operational concepts to satisfy future demand by phase of operation:

  • airport operations

  • terminal area operations

  • en route and oceanic operations

Safety and security risk management systems should be embedded in each of the above operational concepts, not set apart as separate considerations. The Integrated Plan should describe an iterative process for defining and assessing operational concepts as they relate to quantifiable system performance goals. The process should involve discussions with stakeholders and progressively more detailed modeling and simulation to assess performance and identify problems and guiding principles. The JPDO should support research to enhance and assess modeling and simulation capabilities.


National Aeronautics and Space Administration (NASA). 2004. Design and Testing of a Low Noise Flight Guidance Concept. NASA/TM-2004-213516. Hampton, Va.: Langley Research Center. Available online at <http://techreports.larc.nasa.gov/ltrs/PDF/2004/tm/NASA-2004-tm213516.pdf>.

National Research Council (NRC). 2002. Making the Nation Safer: The Role of Science and Technology in Countering Terrorism. Washington, D.C.: The National Academies Press. Available online at <www.nap.edu/html/stct/index.html>.

Next Generation Air Transportation System Joint Planning and Development Office (NGATS JPDO). 2004. Next Generation Air Transportation System Integrated Plan. Washington, D.C.: JPDO. Available online at <www.jpdo.aero>.

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