I am participating in the NASA small UAS trajectory modeling project. This project will contribute to the future UAS traffic management (UTM) system. The rules and regulations for manned aircrafts have established through a long history, and we now have organized traffic control systems such as airspace classes, control towers, regulated radio communication, etc. The control tower gives a different instruction to a pilot depending on the category, class, and types of the aircraft. Also, the operation is different even between the same types because each aircraft has a different set of instruments and various performances. In order to make regulations for UTM, we first need to figure out what unmanned aircraft could have what kind of trajectory. The existing traffic tower systems rely on the base of aircraft data (BADA) to predict a trajectory. Our first goal is to make additions and modifications to this data to accommodate the models of small UAS and to test our model through simulations and flight testing.