The Modeling and Simulation Branch ANG-C55 conducts research to validate new aviation concepts technologies, and system capacity issues, which evaluate the performance of both emerging and existing systems within the National Aviation System (NAS). The research utilizes a variety of engineering and scientific disciplines such as modeling, rapid prototyping, fast-time simulation, applied statistical methods, object oriented programming, and real time human-in-the-loop simulation techniques. The Branch adheres to a system engineering validation process to assess the operational and technical feasibility of proposed system changes to the NAS concept of operations. Products resulting from these efforts are used to support the mission and investment analysis decisions of the NAS acquisition management process.