MIT Modeling Research Under NASA/AATT

Executive Summary

ATM systems throughout the world are entering a period of major transition and change. The combination of important technological developments and of the globalization of the air transportation industry has necessitated a re-examination of some of the fundamental premises of existing ATM concepts. New ATM concepts have to be examined, concepts that may place more emphasis on: strategic traffic management, planning and control; partial decentralization of the decision-making process; and added reliance on the aircraft to carry out strategic ATM plans, with ground controllers confined primarily to a monitoring and supervisory role. `Free FlightÕ is a case in point. In order to study, evaluate and validate such new concepts, the ATM community will have to rely heavily on models and computer-based tools/utilities, covering a wide range of issues and metrics related to safety, capacity and efficiency. The state of the art in such modeling support is adequate in some respects, but clearly deficient in others. It is the objective of this study to assist in: (i) assessing the strengths and weaknesses of existing fast-time models and tools for the study of ATM systems and concepts and (ii) identifying and prioritizing the requirements for the development of additional modeling capabilities in the near future. A three-stage process has been followed to this purpose: Through the analysis of two case studies involving future ATM system scenarios, as well as through expert assessment, modeling capabilities and supporting tools needed for testing and validating future ATM systems and concepts were identified and described. Existing fast-time ATM models and support tools were reviewed and assessed with regard to the degree to which they offer the capabilities identified under Step 1. The findings of 1 and 2 were combined to draw conclusions about (i) the best capabilities currently existing, (ii) the types of concept testing and validation that can be carried out reliably with such existing capabilities and (iii) the currently unavailable modeling capabilities that should receive high priority for near- term research and development. In this report, we present the results of these three stages. The next section provides an outline of the contents of the study and of the structure of the report. It should be emphasized, at this point that the study is concerned only with "fast time" analytical and simulation models. "Real time" models, that typically involve humans-in-the-loop, comprise another extensive class which is not addressed in this report. Relationships between some fast-time and some real-time models are, however, mentioned in several parts of this report and the potential combined use of these two classes of models --a very important subject-- is addressed in Chapters 4 and 7.