The European SORA Standard

** ADI takes no position on whether SORA should be implemented - this is a model regulation for educational and reference purposes.

The Specific Operations Risk Assessment (SORA) framework is a methodology developed by the European Union Aviation Safety Agency (EASA) for assessing and mitigating risks associated with drone operations. It plays a crucial role in Europe's approach to regulating unmanned aircraft systems (UAS) operations, particularly those that fall outside the standard scenarios covered by the "open" category of operations.

SORA is designed to assist drone operators and national aviation authorities in assessing the risk of specific drone operations and determining appropriate safety requirements. It employs a risk-based methodology, meaning that the level of scrutiny and the mitigations required are proportional to the risk posed by the operation. The framework takes a holistic approach, considering both ground and air risks associated with drone operations.

SORA follows a systematic, step-by-step process to identify hazards, assess risks, and determine necessary safety objectives. It establishes Operational Safety Objectives (OSO), which are specific safety requirements that must be met based on the assessed level of risk. The framework categorizes operations into different Ground Risk Classes (GRC) and Air Risk Classes (ARC) based on factors such as the operational environment, drone characteristics, and proximity to people or other aircraft.

Based on the overall risk assessment, SORA assigns a Specific Assurance and Integrity Level (SAIL), which determines the level of robustness required for the various OSOs. The framework allows for flexibility, enabling operators to propose a range of mitigations to reduce risk and potentially lower the SAIL.

SORA aims to provide a standardized approach across EU member states, facilitating cross-border operations. It is particularly relevant for "specific" category operations under the EU drone regulations, which cover operations with medium risk. The framework is designed to evolve based on operational experience and technological advancements.

SORA has gained widespread acceptance in the drone industry and is being adopted or considered by aviation authorities outside of Europe as well. Proper application of SORA requires training and expertise in risk assessment and drone operations. The framework is integrated into the broader European regulatory framework for drones, complementing other elements such as registration requirements and remote identification.

The SORA framework is designed to be scalable, applicable to a wide range of drone operations from simple to complex. While it provides a comprehensive approach to risk assessment for drone operations, it's worth noting that its application can be complex, especially for more intricate operations. Many operators work with consultants or develop in-house expertise to effectively apply the SORA methodology.

The 10 Steps of SORA

These steps guide operators and regulators through a comprehensive risk assessment and mitigation process for drone operations. These ten steps provide a structured approach to assessing and mitigating risks associated with drone operations. They ensure that all relevant factors are considered and that appropriate safety measures are in place before an operation is approved. It's important to note that while these steps provide a general framework, the specific application of SORA can vary depending on the complexity of the operation and the requirements of individual regulatory authorities.

  1. ConOps - The operator defines the Concept of Operations (ConOps) for the intended drone mission. This includes details about the operation, such as the type of drone, the operating environment, and the mission objectives.

  2. Determination of UAS Ground Risk Class - Based on the operational scenario, the Ground Risk Class (GRC) is determined. This considers factors like the size of the drone, the operational scenario, and the population density in the area of operation.

  3. Final GRC Determination - The initial GRC is then modified based on any available mitigations for ground risk. These might include measures like a low impact angle or the use of a parachute system.

  4. Determination of Initial Air Risk Class - The initial Air Risk Class (ARC) is determined based on the airspace environment where the operation will take place. This considers factors like the altitude of the operation and the air traffic density in the area.

  5. Application of Strategic Mitigations - Strategic mitigations are applied to potentially lower the initial ARC. These might include measures like operating in controlled airspace or during times of low air traffic.

  6. Final ARC Determination - After applying strategic mitigations, the final ARC is determined.

  7. SAIL Determination - The Specific Assurance and Integrity Level (SAIL) is determined based on the final GRC and ARC. The SAIL indicates the overall level of risk for the operation.

  8. Identification of Operational Safety Objectives - Based on the SAIL, a set of Operational Safety Objectives (OSOs) are identified. These are the safety requirements that must be met for the operation.

  9. Adjacent Area/Airspace Considerations - The potential impact on adjacent areas or airspace is considered. This includes assessing the risk to areas surrounding the operational area and any necessary coordination with adjacent airspace users.

  10. Comprehensive Safety Portfolio - All the previous steps are compiled into a comprehensive safety portfolio. This includes a description of the operation, the risk assessment, all identified mitigations, and how the OSOs will be met.