Potential NASA Commercial Applications: Significant opportunities exist for the use of Unmanned Aircraft Systems in the NAS, particularly for commercial applications. In this proposed effort, we will develop a set of optimization/simulation models to support the accommodation and integration of UAS into the NAS. These optimization/simulation models will be based on previously-developed DAC algorithms which we will adapt to accommodate UAS. At the end of each Phase of the effort, these concepts and algorithms will be transferred to NASA. These models are expected to support evaluation of NextGen concepts and consequently expedite the NAS transformation, and can be used by NASA within other NASA simulation environments and technology to handle airspace management functions related to UAS.