Understanding the New UK SORA Methodology

The UK Civil Aviation Authority (CAA) has officially adopted the UK Specific Operations Risk Assessment (UK SORA) as the new standard for authorising drone operations in the Specific Category. This represents a significant shift from the previous Operating Safety Case (OSC) system and aligns the UK more closely with international standards set by organisations like the Joint Authorities for Rulemaking on Unmanned Systems (JARUS).

What is UK SORA?

The UK Specific Operations Risk Assessment (SORA) is a structured, multi-stage approach to evaluating and mitigating risks associated with drone operations in the Specific Category. Rather than following a fixed, prescriptive set of guidelines, UK SORA provides drone operators with a robust framework to systematically assess potential hazards both on the ground and in the air, and implement appropriate measures to ensure operational safety.

At its core, UK SORA involves assessing two main categories of risk:

• Ground Risk – the likelihood and impact of a drone operation harming people, property, or infrastructure on the ground.
• Air Risk – the likelihood and potential severity of a drone operation interfering with or colliding with manned aircraft in flight.

By carefully analysing these risks, operators can identify and apply mitigations tailored specifically to their operational scenarios, offering increased operational flexibility compared to the earlier OSC approach.

Major Changes Introduced by UK SORA

The move from OSC to UK SORA brings several new and important concepts for drone operators:

1. Ground Risk Class (GRC)
   The Ground Risk Class assesses the risk posed by the drone to people or infrastructure on the ground. It considers factors such as drone size, operational environment, and population density. GRCs range from low-risk rural areas (GRC 1) to densely populated urban environments (GRC 10).

2. Air Risk Class (ARC)
   The Air Risk Class measures the likelihood of encountering manned aircraft during the operation. This assessment is influenced by operational altitude, airspace complexity, and aircraft density. Lower ARCs represent lower risk of collision, while higher ARCs indicate increased likelihood of encountering other aircraft.

3. Specific Assurance and Integrity Levels (SAIL)
   Once the Ground and Air Risk Classes have been determined, operators combine these into a Specific Assurance and Integrity Level (SAIL). The SAIL level dictates the robustness required of your mitigations and safety measures. A higher SAIL rating means operators must implement stricter and more verifiable mitigations.

4. Enhanced Operational Flexibility
   SORA enables operators to define their own risk mitigations based on their unique operational context. This approach allows complex drone operations, such as Beyond Visual Line of Sight (BVLOS) flights or operations in controlled airspace, to become achievable under carefully managed conditions.

What About PDRA‑01?

Although the UK SORA methodology is now the standard pathway for all new Specific Category operations not covered by predefined cases, it’s important to clarify that PDRA‑01 remains available until at least 31 March 2026.

PDRA‑01 provides a simplified, pre-defined risk assessment for standard VLOS operations in built-up areas, and many operators continue to hold valid authorisations under its conditions.

• If you're flying within PDRA‑01 limits (e.g. VLOS, under 25 kg, with GVC), you can continue to apply under PDRA‑01 for now.
• The CAA has stated that no immediate changes will be made to PDRA‑01, and existing authorisations remain valid until expiry.
• However, operations outside PDRA‑01's scope (e.g. BVLOS, flights near uninvolved people beyond current separation limits, larger aircraft, or higher-risk airspace) now require a full UK SORA-based application.

Key Differences: PDRA‑01 vs SORA-Based Applications

Feature	PDRA‑01	UK SORA
Valid Until	31 March 2026 (at least)	Now required for all non-PDRA‑01 operations
Flight Conditions	Fixed template (VLOS, ≤25 kg, GVC)	Custom per mission, more flexible
Risk Assessment	Predefined by CAA	Fully operator-driven (GRC/ARC/SAIL)
Application Complexity	Minimal	Moderate to high (requires detailed safety case)
Operational Scope	Limited to standard scenarios	Enables BVLOS, complex airspace, urban ops

If you're currently flying under PDRA‑01, there's no immediate need to transition, but you should begin familiarising yourself with SORA, particularly if you're planning more complex operations in future.

What This Means for Drone Pilots

The implementation of UK SORA fundamentally changes how commercial drone operators prepare for Specific Category operations. While the flexibility offered is beneficial, it demands greater knowledge and a proactive approach to safety and risk management.

Operators will need to develop comprehensive safety cases, clearly documenting risk assessments, mitigation strategies, and operational procedures tailored specifically to their mission profiles.

The transition to UK SORA also introduces increased accountability and oversight from the CAA, which will closely evaluate and audit operators' SORA submissions and ongoing compliance.

PDRA‑01 continues to serve as a valuable, lower-barrier option for standard operations during this transition period, but its long-term future remains uncertain.

Practical Support for Operators

To assist operators with this transition, UK Drone Compliance Guide has developed several tools and resources designed to simplify the UK SORA process:

• Our new Compliance Calculator offers step-by-step guidance to determine GRC, ARC, and SAIL levels, ensuring accurate and compliant assessments.
• We provide clear, user-friendly templates and example safety cases to help you craft your own robust documentation.
• Regular updates and insights from industry experts are published in our blog, keeping you informed about regulatory changes and best practices.

Final Thoughts

The introduction of the UK Specific Operations Risk Assessment (SORA) represents a significant leap forward for commercial drone operations in the UK. Although the transition from the OSC methodology presents some initial challenges, the long-term advantages, greater operational flexibility, enhanced safety, and alignment with international standards, far outweigh the short-term effort involved.

Operators currently using PDRA‑01 can continue to do so until at least March 2026, but the direction of travel is clear: SORA is the future. By understanding and embracing the SORA methodology now, drone pilots and commercial operators can stay ahead of the curve and unlock new operational opportunities with confidence.

Stay informed and compliant by regularly checking our website for the latest updates and guidance on navigating UK SORA.