A Risk Analysis of Unmanned Aircraft Systems (UAS) Integration into non-Segregate Airspace

Air transportation is essential for society and the number of flights worldwide leads to high revenue. Although new technologies are under development to improve the airspace operation (e.g., regarding safety), this increasing traffic presents complex situations to Air Traffic Control (ATC). In this context, reducing the probabilities of occurrence of possible risky events is essential and actions must be taken to avoid them. Among the technologies under development, Unmanned Aircraft Systems (UAS) can be highlighted. One important type of UAS is the Remotely Piloted Aircraft System (RPAS). The operation of these autonomous aircraft has increased in the past few years into segregated airspace. However, to integrate them into the non-segregated airspace, many challenges must be faced and risk analysis that considers hazards related to their operation must be conducted. A risk analysis of specific problems that may happen in RPAS operation is performed herein. The hazards of this new kind of aircraft present new ways of reaching unsafe states (e.g., loss of communication between pilot and aircraft) and the hazards related to its integration are presented considering both qualitative and quantitative analysis. The qualitative analysis is conducted using Risk Safety, proposed by the International Civil Aviation Organization (ICAO). The quantitative analysis employs Fault Tree Analysis (FTA). The results showed that, for allowing this kind of aircraft to share the same airspace with manned aircraft, mitigation actions must be adopted by authorities as well as special treatment to the potential source of events that lead to unsafe states (e.g., communication systems), especially those related to security issues.