ABSTRACT
Unmanned Aircraft Systems (UAS) are no longer technological systems of the unforeseeable distant future, but rather of the present and near future. They are systems that are evolving quickly and will soon become commonplace in the National Airspace System (NAS). However, opening the NAS to civil UAS is a challenging task, a task that encompasses multiple safety issues which include detect-and-avoid implementations, self-separation procedures, and collision avoidance technologies to remain well clear of other aircraft. Routine access to the NAS will require UAS to have new equipage, standards, rules and regulations, and procedures, among others, in addition to many supporting research efforts to answer difficult questions concerning how these aircraft will operate in airspace with manned aircraft. As a result, the National Aeronautics and Space Administration (NASA) has established a multi-center “UAS Integration in the NAS” project to examine essential safety concerns, in collaboration with the Federal Aviation Authority (FAA) and industry, regarding the integration of UAS in the NAS. Among these guiding research efforts were the NASA Langley Research Center’s Controller Acceptability Study (CAS) series, which looked at how Air Traffic Controllers would maintain traffic separation in busy airspace when some of the aircraft were UAS with detect-and-avoid equipment.
