SORA-ready UAS design: a UAS manufacturer’s guide to EASA and UK compliance in 2026.
- Anne-Lise Scaillierez
- 2 days ago
- 7 min read
A short note before we start: this article assumes some familiarity with the Specific Operations Risk Assessment, SORA. If SORA is new to you, the UK SORA Compliance page on this site is a faster primer and a good place to come back from. Key terms used below are expanded on first appearance and listed in the Sources and further reading section at the end. |
This article is for UAS designers, manufacturers and integrators preparing aircraft for the United Kingdom or the European market in 2026. It explains the regulatory landscape on both sides of the Channel, where design decisions sit, and the evidence pack required to achieve a recognised aircraft design under SORA.
A shared foundation: SORA as the common safety methodology
The Specific Operations Risk Assessment (SORA) is the framework governing mediumrisk drone operations in both the UK and EASA jurisdictions. It was developed by JARUS, a consortium of aviation authorities and experts, including both EASA and the UK CAA.
UAS Design Assurance as part of SORA
Design assurance sits at the heart of SORA, even though it has historically received far less attention than operational planning. For most of the past five years, the commercial drone market has operated predominantly at low SAIL levels or within standard scenarios, where designrelated OSOs are minimal and the regulatory burden falls largely on the operator rather than the manufacturer. As a result, many UAS designers have not yet had to confront the deeper engineering, documentation and assurance expectations embedded in SORA. That changes at SAIL 3 and above. At these levels, SORA becomes a design assurance framework: it defines the reliability, software assurance, containment performance, detectandavoid capability, configuration control and lifecycle discipline that an aircraft must demonstrate to support mediumrisk operations. The required level of rigour increases sharply from SAIL 2 to SAIL 3, and again from SAIL 3 to SAIL 4, where highrobustness mitigations and formal design verification come into play.
For manufacturers, understanding SORA’s design assurance expectations early is essential to building an aircraft that can credibly support the missions and markets they intend to serve.
Adoption timelines
UK: Adopted SORA v2.5 as Acceptable Means of Compliance (AMC) and Guidance Material (GM) on 3 March 2025 (ORS9 Decision No. 46), with full implementation, replacing the previous Operating Safety Case approach, from 23 April 2025.
EASA: Adopted SORA v2.5 into its AMC/GM for Regulation (EU) 2019/947 through ED Decision 2025/018/R, published 29 September 2025. SORA 2.5 became immediately applicable across the EU on that date, though individual Member States may run a transition period of up to six months during which SORA 2.0 applications are still accepted; authorisations granted under SORA 2.0 during that window remain valid for up to two years.
Both regulators have implemented SORA v2.5 with limited national deviations though, as discussed below, their review mechanisms for design compliance may be more different than their underlying risk methodology.
Regulatory baseline
The UK retained EU Regulations 2019/947 (operations) and 2019/945 (product requirements) at Brexit. These remain the foundation of the UK’s Open, Specific and Certified categories, with amendments made through UK AMC/GM updates.
UAS design requirements in the Specific Category: still early days
Europe (EASA)
Open Category
Class marking (C0–C4) has been in place for several years. EASA has also created:
• C5 and C6 class marks for Standard Scenarios (STS) in the Specific Category.
• A forthcoming agricultural class mark, currently under development.
Specific Category (SAIL 3+)
EASA’s full set of AMC/GM for SORA OSOs under SAIL 3 was published via ED Decision 2025/018/R on 29 September 2025, completing the technical framework for design-related compliance at this level. EASA also runs an automated platform, the IAM HUB, to support operators through Phase 1 of the SORA process (deriving operational requirements).
However, practical implementation is still limited:
• Very few SAIL 3compliant drones are available on the EU market.
• EASA has shifted from centralised review to National Aviation Authorities (NAAs), and now toward manufacturer selfdeclaration for SAIL 3 compliance, due to resource constraints and slow market uptake.
United Kingdom (CAA)
Open Category UK class marking was introduced for new products placed on the market from 1 January 2026. UK5 and UK6 are reserved for Specific Category operations requiring a CAA operational authorisation; UK0–UK4 cover Open Category use. EU class-marked drones (C0–C6) remain recognised as their equivalent UK class until 31 December 2027, after which non-UK-marked aircraft become "legacy" aircraft subject to weight-based restrictions.
UK and EU class-marking requirements remain materially aligned, as reflected in the UK AMC/GM for 2019/945 and 2019/947.
Specific Category The UK launched its design-review framework, the SAIL Mark, in March 2025, underpinned by:
• CAP722K: SAIL Mark policy concept
• CAP722J: Recognised Assessment Entity for Flightworthiness (RAE(F)) policy, covering the entities who carry out the technical assessment behind a SAIL Mark
The SAIL Mark simply offers a reusable, pre-assessed route so an Operator doesn't have to resubmit full design evidence every time they apply to fly that aircraft. Where granted, a SAIL Mark Certificate's validity extends for the in-service life of the UAS, unless a major modification is made.
The SAIL Mark scheme is optional, there is no obligation for a UAS Designer to obtain one. A Designer can instead support an Operator's authorisation application directly. That Drone Operator must nevertheless go through the process of SAIL 3 authorisation and must provide the relevant documentation for all UAS Design OSOs for assessment by the RAE(F).
UKRI funded a SAIL Mark Certificate programme, and several UAS and accessories are currently undergoing review.
Convergence or divergence?
It is too early to determine whether EASA and the UK will diverge. Current evidence suggests a potential for UK flexibility that may recognise:
• EASAbased design reviews
• FAAbased design reviews
This is supported by the CAA’s ability to accept thirdparty assessments via RAE(F) and its broader discretion under UK retained law. Industry reports indicate that a US delivery drone system is expected to receive a UK SAIL 3 certificate.
There is currently no mutual recognition of SAIL design reviews between EASA and the UK. This is not surprising:
• Brexit removed automatic recognition pathways.
• Both regulators have only recently implemented SORA 2.5.
• There is limited return of experience yet to justify harmonisation.
Review pathways: declaration vs thirdparty assessment
A major challenge for both regulators is the availability of qualified experts to review UAS designs. This has shaped their respective approaches.
Summary table
Category | EASA | UK |
Open Category | C0–C2 Notified Body; C3 moving to self-declaration | UK0–UK4 CAA-overseen; EU C0–C6 accepted until end 2027 |
Standard Scenarios | C5/C6 via Notified Body | n/a |
|
|
|
SAIL 2 mitigations | Declaration of compliance with MoC by Designer: • Containment Medium Robustness • M2 Medium Robustness
Review by EASA, DVR: • M2 High Robustness • Containment High Robustness • (And medium robustness if compliance does not follow the official MoC) | Review by an RAE(F) then CAA: • Sheltering for UAS >25kg • M2 Mitigation Medium & High Robustness • Containment Medium & High Robustness |
SAIL 3 UAS | Manufacturer self-declaration | RAE(F) review + CAA |
SAIL 4 UAS | EASA DVR (mandatory) | RAE(F) review + CAA |
SAIL 5/6 UAS | EASA Type Certificate (Part 21) | RAE(F) review + CAA |
The evidence pack manufacturers underestimate
Both EASA and the UK require structured evidence aligned with the SORA OSOs and robustness levels, as well as UAS Design means of compliance.
The visible part of a UAS SAIL Design Verification is the test campaign. Flight testing, environmental testing, performance characterisation. Most engineering teams scope this work properly during the budget exercise.
The under-scoped part is the documentation. A credible submission includes the failure mode and effects analysis tied to specific Operational Safety Objectives, the software development lifecycle evidence, the hardware acceptance records, the maintenance philosophy and the change control procedure. Each of those documents needs to exist as a primary artefact, not a retrospective summary.
Manufacturers should treat documentation as a deliverable from day one of design.
When to bring regulation into the conversation.
Regulation should enter the design conversation far earlier than many manufacturers expect, ideally at the concept stage, before architecture is locked in and long before prototypes fly. SORAdriven requirements such as containment performance, M2 mitigation robustness, then in higher SAILs design assurance, software assurance levels, and configuration control are not features that can be bolted on later without significant redesign. Early engagement with the regulatory framework ensures that design choices align with the Operational Safety Objectives (OSOs) and robustness levels the aircraft will ultimately need to demonstrate. It also prevents costly rework, accelerates the path to SAIL 3 or SAIL 4 readiness, and allows manufacturers to shape a credible evidence pack as the aircraft matures.
In short, regulation is not an endofprocess hurdle. It is a design input, and the sooner it is integrated, the smoother the approval journey becomes.
Bringing a UAS to market under SORA is ultimately a strategic exercise in design assurance, evidence generation and regulatory alignment. Manufacturers who approach these elements deliberately, rather than reactively, move faster, avoid costly redesign, and have a higher potential to reach their goals and genuinely support their commercial model. If your organisation is preparing a new platform or advancing an existing one through SAILbased design review, we can support you. The Drone Office works with UAS designers and manufacturers across the UK and Europe to structure SORA programmes, develop compliant evidence packs, and navigate pathways with regulators. We are always open to an initial conversation to understand your objectives and explore how we can help.
Working on a UAS for the UK or EU market? The Drone Office works with designers and manufacturers across the UK and Europe on SORA-ready aircraft and the documentation that carries them through assessment. Book an introductory call: thedroneoffice.com/contact |
Sources and further reading.
Primary references for the regulations and frameworks cited in this article. All documents below are public and freely accessible from the issuing authority. Anyone authoring a UAS submission should be working from the current published version of each.
UK Civil Aviation Authority.
1. AMC and GM to Article 11, ORS9 Decision No. 46. The operative reference for SORA authorship in the UK. https://www.caa.co.uk/publication/download/22617
2. CAP722K, UAS SAIL Mark Policy. How aircraft are recognised at a given SAIL in the UK. https://www.caa.co.uk/publication/download/22716
3. CAP722J, Recognised Assessment Entity Policy. Who can assess aircraft against CAP722K. https://www.caa.co.uk/publication/download/22715
4. CAP722, Unmanned Aircraft System Operations in UK Airspace. General orientation document. https://www.caa.co.uk/our-work/publications/documents/content/cap722/
5. RAE(F) requirement tables for OA applicants
European Union Aviation Safety Agency.
6. EU Regulation 2019/947, Implementing Regulation on UAS operations. https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32019R0947
7. EASA Easy Access Rules for Unmanned Aircraft Systems. SORA v2.5 sits inside this document. https://www.easa.europa.eu/en/document-library/easy-access-rules/easy-access-rules-unmanned-aircraft-systems-regulations-eu
JARUS framework.
8. JARUS Specific Operations Risk Assessment, SORA. The framework adopted by both regulators. https://jarus-rpas.org/publications/
Internal references.
9. The Drone Office UK SORA Compliance page. A primer for readers newer to SORA. https://thedroneoffice.com/uk-sora-compliance
10. The Drone Office SORA-Ready UAS and Flightworthiness page. The pillar page this article supports. https://thedroneoffice.com/sora-ready-uas-flightworthiness
11. The Drone Office SAIL Marking page. Detail on the UK SAIL Mark pathway. https://thedroneoffice.com/sail-marking
Draft for Anne-Lise sign-off. wevisualise Limited © 2026.
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