Quantification of High Level Safety Criteria for Civil Unmanned Aircraft Systems

The civil Unmanned Aircraft System (UAS) sector is growing rapidly, with a notable orientation towards applications considered too dull, dirty, dangerous or demanding for conventionally piloted aircraft. Operations in this sector present hazards of two main kinds: to other aircraft, and to people and property overflown by UAS. Methods currently used for assessing these hazards and for managing safety and risk are less than comprehensive. This paper commences with a review of existing High Level Safety Criteria for UAS, including safety metrics, hazard metrics and risk metrics for manned aircraft operations and other modes of transportation. A set of quantified risk criteria for UAS operations is then developed, consistent with the As Low As Reasonably Practicable (ALARP) risk management framework used in current regulatory practice.