(Specific Operations Risk Assessment)
SORA (Specific Operations Risk Assessment) is a tool developed by JARUS (Joint Authorities for Rulemaking on Unmanned Systems) to perform the safety assessment of UAS operations in the “Specific” category.
SORA methodology is made up of a “main body” document (describing the risk assessment process as a whole) and a set of complementary Annexes, providing guidance on specific issues. The methodology consists of a step-by-step procedure for the evaluation of Ground Risk (i.e. the risk of a person being struck by the UAS crashing on the ground) and Air Risk (i.e. the risk of collision between a UAS and a manned aircraft). By combining both Ground and Air Risk, it is possible to determine a general risk parameter (SAIL, i.e. Specific Assurance and Integrity Level), representing the level of confidence that the UAS operation will stay under control. The SAIL is then directly associated to a list of pre-defined barriers (alias safety mitigations) which shall be implemented with a certain level of robustness. These barriers are addressed to mitigate specific risk areas (such as technical issues with the UAS, human error etc..). The higher the SAIL, the higher the robustness level required for each single barrier. Although providing a guided approach, the method results to be quite flexible. In fact, it allows to introduce additional safety mitigations which may be deriving both from the peculiarities of the intended operation and the introduction of new technologies or services.
EuroUSC Italia, as an active member of JARUS WG 6, is closely following the development of SORA and is already applying it in several projects dealing with challenging and innovative UAS operations. For instance, EuroUSC-Italia is involved in DREAMS project (financed by SESAR JU within the EU H2020 program) where SORA is being used to perform the safety assessment of UAS operations in the UTM (Unmanned Traffic Management) context. Within this project, SORA allowed to highlight the safety benefits deriving from the use of U-Space services supporting UAS operations.
Once the new EU regulation on UAS operations will entry into force, SORA will become an official AMC of EASA, as outlined in the Opinion 01/2018. As prescribed by the new regulation, a risk assessment will be mandatory to operate in the “Specific” category. Therefore, it is expected that SORA methodology will be applied either directly by operators or by competent authorities when defining standard scenarios.
HOW WE CAN SUPPORT YOU IN USING SORA
In this context EuroUSC Italia can provide support to operators at two different levels:
• Perform a “traditional” SORA based safety assessment: starting from the Conops in which the operator has defined all the operational details (purpose of the mission, UAS employed, flight conditions, overflown environment, location, etc), it is possible to evaluate, in sequence, Ground Risk, Air Risk and the SAIL associated to the operation. Compliance with safety requirements prescribed by SORA is checked; if the operator’s technical and organisational aspects do not fulfil SORA requirements, mitigation strategies are proposed, possibly establishing an iterative process.
• Perform a “reverse” SORA based safety assessment: starting from the organisational details and the technical features of the UAS employed, it is possible to determine the range of operations allowed by SORA. First it is evaluated the SAIL that the operator is compliant with and then the maximum risk level (in terms of Ground and Air Risk) that can be safely managed.
For instance, the operator will be able to know if he is allowed to fly his UAS in BVLOS conditions, over urban environment or in high density airspace classes.
Possible technical or organisational improvements are suggested to allow a wider range of operations.
If you need our help and want to know more, contact us!