Thesis (Ph. D. in Technology, Management, and Policy)--Massachusetts Institute of Technology, Engineering Systems Division, Technology, Management, and Policy Program, 2008."June 2008."Includes bibliographical references (p. 227-244).The US Air Transportation System is currently facing a number of challenges including an increasing demand for travel and growing environmental requirements. In order to successfully meet future needs, the system will need to transition from its current state using a combination of technology, infrastructure, procedure, and policy changes. However, the complexities of the air transportation system make implementing changes a challenge. In particular, the multi-stakeholder nature of the system poses a significant barrier to transition. Historically, many changes in the air transportation system were driven by safety concerns and implemented following accidents which provided the momentum to overcome transition barriers. As a result of past changes, the system has become increasingly safe resulting in the emergence of new drivers for change. Security has emerged as a driver following the terrorist attacks of 9/11/2001 in the US and a number of system changes have since been implemented. Currently, capacity is one of the largest drivers of change. Addressing capacity issues requires solutions that can be accepted by stakeholders, and pass the necessary certification and approval requirements for implementation. The contribution of aviation to global greenhouse gas emissions is also becoming a significant driver for change in the system. The goal of this work is to understand how the air transportation system changes in response to safety, security, capacity, and environmental drivers for transition. In order to understand the dynamics of transition, historical cases of system change were studied. Twenty seven such cases have been analyzed to construct a feedback process model of transition and to explore specific change dynamics observed.(cont.) These dynamics include: understanding the role of crisis events as catalyst for change; the effect that timing of solution development has on the overall time constant for change; the role that stakeholder objectives play in the transition process, and the use of approval and certification processes to stall or block change. understanding the process of change in the US Air Transportation System can inform future changes in aviation as well as in other systems with similar properties.by Aleksandra L. Mozdzanowska.Ph.D