Howe-Veenstra, Ryan2011-12-142011-12-142011-11https://hdl.handle.net/11299/119038University of Minnesota M.S. thesis. November 2011. Major: Aerospace engineering and mechanics. Advisor: Dr. Yiyuan J. Zhao. 1 computer file (PDF) vi, 69 pages, appendix A.The Next Generation Air Traffic System (NextGen) offers a historical opportunity to re-examine the assumptions and constraints in the current Air Traffic Control (ATC) system and their effects on ight efficiency and safety. Modern day commercial air- craft are fully capable of ying continuously varying smooth trajectories. However in the current air traffic control ATC system, commercial ight trajectories consist of a series of segments due to historical development of navigation and surveillance systems. Segments are defined by one or more constant parameters such as Mach number or altitude. In this paper, characteristics and efficiencies of optimal free ights when ATC constraints are absent and optimal segmented ights in the current ATC system are compared. In this paper, aircraft ights are modeled as a point-mass. Both horizontal and vertical ight profiles are considered. Results of this paper seek to determine the potential benefit of supporting continuous trajectories in future ATC systems.en-USAerospace engineering and mechanicsThesis or Dissertation