The IAA Approves the First UAS STS Declaration

Celebrating a Milestone in Irish Unmanned Aviation: The IAA Approves the First UAS STS Declaration.

We are thrilled about a recent announcement made by the IAA and a significant milestone in the UAS operator journey towards a broader range of UAS operations. We continue working closely with UAS operators to help them navigate regulations across EASA and the UK. At the same time, we always get a request to advise on which drones they should purchase so that they can be well-prepared for future regulatory changes.

Our organisation has successfully assisted and continuously worked alongside UAS operators to obtain and keep their operational authorisations. That could be an operational authorisation application for a Light UAS Operator Certificate (LUC), applications under the Specific Operations Risk Assessment (SORA) framework, Predefined Risk Assessments (PDRAs) or declarations under Standard Scenarios (STSs) to the national aviation authority. This experience underscores our commitment to advocating for the highest safety and compliance standards and leading the way in innovative aviation training and compliance practices.

We will see more class-identified drones arriving on the market. The question starts to appear on the horizon - which way should I go? Should I apply under SORA, STS or PDRA? That would depend on your concept of operations, such as UAS, type of operations, and location. This article will review the difference between applying under STS or PDRA, as these are closely connected. 

Navigating the Skies: STS vs. PDRA

Navigating the regulatory environment is as crucial as mastering the skies in drone operations. Two pathways offer distinct advantages and considerations for drone operators: the Standard Scenario (STS) and the Predefined Risk Assessment (PDRA). As we celebrate the issue of this STS declaration, it's an excellent opportunity to compare these two paths towards being compliant and operational in the UAS 'specific category', especially for those contemplating the best approach to compliance and operational efficiency. For either an STS declaration or an Operational Authorisation application under PDRAs, UAS operators must develop and submit a regulatory-compliant operations manual as supporting documentation.

The Standard Scenario (STS) Advantage

The STS route is explicitly tailored for particular drones with specific class markings (i.e. C5/C6) and other conditions (e.g. visibility (VLOS vs BVLOS with limitation on max distance), height limits (e.g. 120 m AGL) providing a streamlined and lower level of costs to achieve regulatory compliance. Two published Standard Scenarios under EASA UAS regulations are STS-01 and STS-02. The price is relatively lower (in Ireland, the cost is 300€ for a 2-year valid declaration). The STSs offer a clear and concise pathway for operators of C5/C6 drones to meet the necessary safety standards without the burden of extensive paperwork or the higher costs associated with more comprehensive operational risk assessments. This makes STS an attractive option for operators whose fleets consist solely of C5 or C6 class-identified drones.

The Extensive Coverage of PDRAs

On the other hand, the PDRAs extend beyond the class-identified drones, encompassing a more comprehensive range of drones and concepts of operations as long as they adhere to predefined mitigation measures and compliance requirements. There are currently five published and three more PDRAs in the works. PDRA-S01 and PDRA-S02 are directly derived from the Standard Scenarios, while others, G01-G03, are generic. Although the PDRA comes with a higher application cost (i.e. in Ireland, this cost is now 1500€ for a 2-year operational authorisation), it provides a broader scope of operation, allowing for the inclusion of non-C5 drones within this regulatory framework. This regulatory compliance pathway benefits operators with diverse fleets that carry drones beyond the C5/C6 classification.

Making the Right Choice: When PDRA Holds the Edge

The decision between STS and PDRA hinges on your drone fleet's composition and operational needs. While STS offers a cost-effective solution for class-identified drones, PDRA stands out as the more advantageous option for those with at least one non-class-identified drone in their fleet. The broader coverage and flexibility afforded by PDRAs can lead to greater operational efficiency and scalability despite their higher initial cost.

If your operations are confined to class-identified drones, the STS pathway presents a streamlined and economical route to compliance. However, for operators looking to maximise their operational scope and adaptability, embracing the PDRA could unlock significant long-term benefits despite its higher initial cost. This strategic investment in PDRA ensures compliance across a wider array of drone classes and positions operators to seize new opportunities in an ever-evolving regulatory landscape.

I invite you to look at various training programs available to remote pilots in the Open Subcategory A2 and Specific Category and for UAS Operators: SORA, Operator's and operation-specific training courses. Review here.

In addition to our training services, our compliance documentation development service provides a step-by-step approach to receiving regulatory-compliant documentation for initial and ongoing regulatory compliance, such as operations manuals, risk assessments and necessary forms to prepare when submitting declarations and applying for authorisations in the Specific Category. Reach out to us here.


As we forge ahead, the choice between STS and PDRA is a strategic decision that should be informed by the diversity of your drone fleet and your vision for the future of your drone operations. Through careful consideration and strategic planning, we can confidently navigate the regulatory skies, ensuring safety, compliance, and the continued growth of drone operations.

February 21, 2024

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