Performance-based Navigation (PBN) allows aviation operations to be conducted based on actual operational requirements rather than the requirements of ground-based equipment. Although the general operational benefits of PBN procedures have been recognized by various studies, there is a need to specify the actual benefits in terms of the frequency of event anomalies that could be expected from the use of PBN procedures. The study reviewed some of the available literature and identified some operational improvements as reported by previous authors. The study then proceeded to review archival data from the Aviation Safety Reporting System (ASRS) database with a view to identifying the link between the use of PBN procedures and reported event anomalies. Overall, there were significantly fewer reported event anomalies when PBN procedures were used than when PBN procedures were not used. It is suggested that air operators and air navigation service providers conduct appropriate risk and safety assessments in their consideration of an increased use of PBN procedures.

The operation of small unmanned aerial systems (sUAS) in the National Airspace System requires a careful consideration of the operating philosophies to ensure a safe outcome for all users. Small UAS operations are explored while the associated risks and benefits from the operations are reviewed. The operation of sUAS in self-separation airspace is discussed by an examination of the concept of autonomous flight rules (AFR). This includes a presentation of the basic principles of AFR and an explanation of the requirement for a sense-and-avoid system. Current and future uses of sUAS are presented to highlight the benefits from their use. Finally, an overview of the major risks associated with the operation of sUAS is provided in the form of a risk assessment matrix and a hazard/risk process decision chart. Mitigation actions to reduce the risks are also specified along with recommendations for further study.