PDRA Explained
PDRA-S02 and PDRA-G01: What Are They and How to Apply Them?
For professional drone operators in the United Kingdom, Predefined Risk Assessments (PDRAs) are essential tools within the Specific Category of UK drone legislation. These standardised risk assessments assist in obtaining operational authorisations by providing predefined risk profiles. In this article, we explain the differences and similarities between PDRA-S02 and PDRA-G01, and offer practical tips on how to use them for compliant and safe flight operations.
What Are PDRA-S02 and PDRA-G01?
PDRA-S02 and PDRA-G01 are Predefined Risk Assessments developed by the UK Civil Aviation Authority (CAA) to facilitate specific drone operations within the Specific Category. They contain pre-analysed risk profiles that allow UAS operators to apply for operational authorisations more efficiently. These PDRAs include fixed operational conditions regarding UAS type, flight methods, and environmental factors.
Differences in Scope and Characteristics
Although PDRA-S02 and PDRA-G01 have similar names, they differ in content and usage:
- **PDRA-S02**: Focuses on BVLOS (Beyond Visual Line Of Sight) operations with a maximum distance of 1 km (or 2 km with designated airspace observers). It is suitable for drones with a maximum take-off mass up to 25 kg and a wingspan up to 3 metres. Operations take place over controlled land in areas with low population density, up to a maximum altitude of 150 metres above ground level.
- **PDRA-G01**: Intended for longer-range BVLOS operations with the use of airspace observers, also possible over controlled or uncontrolled airspace. The maximum flight altitude is also 150 metres and applies to similar drone categories.
- Both focus on surveillance and light cargo applications, with PDRA-G01 more geared towards long-distance flights.
Importance of Current Regulations and National Conditions
Applying a PDRA does not automatically permit an operation in the United Kingdom. The UK CAA checks not only UK regulations but also national restrictions. For example, some BVLOS operations or airspace combinations within the PDRA risk analysis may be permitted in the UK but not necessarily executable in certain UK airspace. Therefore, it is always crucial to check the most recent national policy, for example, via the UK CAA website.
Additionally, the UAS operator must have a valid operational manual that concretely translates the PDRA conditions into their Concept of Operations (ConOps).
How to Implement a PDRA in Your Operation
Implementation requires submitting a comprehensive application to the UK CAA, including a completed PDRA table and an operational manual demonstrating that all operational limitations, technical requirements, and procedures are followed.
Consider the following:
- Who is responsible for airspace observation and how is this organised;
- Monitoring and enforcement of containment around the drone;
- Criteria and processes for safely aborting the mission;
Checklist for Choosing and Using PDRA-S02 or PDRA-G01
To determine which PDRA best fits your operation, it is advisable to explicitly assess the following points:
- Does the drone fly within VLOS or BVLOS?
- What is the type of UAS, maximum MTOM, and wingspan?
- In which type of airspace is the flight conducted: controlled, uncontrolled, or controlled land?
- What is the altitude and distance of the flight?
Frequently asked questions
Can software automatically determine which PDRA applies?
Software tools can assist in structuring the comparison between operational parameters and available PDRAs, but a final assessment and confirmation remain the responsibility of the UAS operator. Current regulations and actual operational conditions must always be validated by the user.
Is it permitted to use only certain parts of a PDRA?
No, a PDRA is designed as a complete set of conditions to which the entire operation must comply. Partially applying or modifying without approval invalidates the PDRA and requires an alternative risk assessment and authorisation process.
How does a PDRA relate to the national rules of the United Kingdom?
Although PDRAs provide UK standards, the UK CAA may impose additional requirements. The UK CAA checks whether operations also meet national safety and airspace criteria, especially for BVLOS and certain airspace sectors.
Do I always need to adjust an operational manual when using a PDRA?
Yes, the operational manual (ConOps) must translate the PDRA-specific conditions into practical procedures and controls used within your organisation. This is crucial for the compliance check by the UK CAA.
What is the difference between a PDRA and a SORA?
A PDRA is a predefined risk assessment for standard operations, intended to expedite the authorisation process. A SORA (Specific Operations Risk Assessment) is used for customised operations outside the scope of available PDRAs and requires a more extensive risk analysis.