The primary goal of Air Traffic Management systems is to ensure safety of operations, in the air and on the ground. While they system have served the National Airspace (NAS) well over the years, the imminent introduction of Unmanned Aircraft Systems (UASs) poses a serious challenge. The variety, flexibility and accessibility of UASs ensures high demand for their use. The low-altitude, small-UAS (sUAS) are perhaps the most attractive platforms due to the low cost to own and maintain. These aircraft pose unique safety risks that are very different from other manned and unmanned aircraft. To address these risks Intelligent Automation, Inc. (IAI) along with its subcontractor Purdue University propose to develop higher fidelity sUAS Trajectory Generator (sUTG) tool for Small UASs. The tool is capable of modeling rotorcraft, fixed wind and hybrid sUAS while accounting for the impacts of winds and sensor uncertainty. The model architecture allows for the use of high fidelity 6-DOF data augmented by flight plan data. The lack of credible trajectory model for sUASs is sorely required for improved mission designs, safety analyses, contingency management and NAS performance estimation. This effort is a step in this direction.