A framework supporting the systematic development of safety cases for Unmanned Aircraft System (UAS) operations in a broad range of civil and commercial applications is presented. The case study application is the use of UAS for disaster response. In those States where regulations do not preclude UAS operations altogether, approvals for UAS operations can be granted on a case-by-case basis contingent on the provision of a safety case acceptable to the relevant National Airworthiness Authority (NAA). A safety case for UAS operations must show how the risks associated with the hazards have been managed to an acceptable level. The foundational components necessary for structuring and assessing these safety cases have not yet been proposed. Barrier-bow-tie models are used in this paper to structure the safety case for the two primary hazards of 1) a ground impact, and 2) a Mid-Air Collision (MAC). The models establish the set of Risk Control Variables (RCVs) available to reduce the risk. For the ground-impact risk model, seven RCVs are identified which in combination govern the probability of an accident. Similarly, ten RCVs are identified within the MAC model. The effectiveness of the RCVs and how they can implemented in terms of processes, policies, devices, practices, or other actions for each of the case-study applications are discussed. The framework presented can provide for the more systematic and consistent regulation of UAS through a "safety target" approach.
[1]
Reece A. Clothier,et al.
Definition of an airworthiness certification framework for civil unmanned aircraft systems
,
2011
.
[2]
Xavier Prats,et al.
Requirements, Issues, and Challenges for Sense and Avoid in Unmanned Aircraft Systems
,
2012
.
[3]
Reece A. Clothier,et al.
Structuring the safety case for unmanned aircraft system operations in non-segregated airspace
,
2015
.
[4]
James T. Reason,et al.
Managing the risks of organizational accidents
,
1997
.
[5]
Reece A. Clothier,et al.
Safety risk management of unmanned aircraft systems
,
2015
.
[6]
César Muñoz,et al.
Concepts of Integration for UAS Operations in the NAS
,
2012
.
[7]
Ella M. Atkins,et al.
Platform-Independent Geofencing for Low Altitude UAS Operations
,
2015
.