Free SORA guide
SAIL levels explained: what your SORA score means for your operation
SAIL (Specific Assurance and Integrity Level) is the result of the SORA risk assessment under Regulation (EU) 2019/947. Your final ground risk class and residual air risk class meet in one table and give a SAIL from I to VI. The higher the SAIL, the more evidence your file needs, so it pays to design the operation for a lower SAIL from the start. If your operation needs one, our team prepares the full SORA operational authorisation and deals with the authority for you.
How SAIL is set
Ground risk plus air risk equals SAIL
Find your final GRC on the left and your residual ARC along the top. The cell where they cross is your SAIL.
| Final GRC | ARC-a | ARC-b | ARC-c | ARC-d |
|---|---|---|---|---|
| 2 or less | I | II | IV | VI |
| 3 | II | II | IV | VI |
| 4 | III | III | IV | VI |
| 5 | IV | IV | IV | VI |
| 6 | V | V | V | VI |
| 7 | VI | VI | VI | VI |
| Above 7 | Certified category, not Specific | |||
SAIL determination table, AMC1 Article 11 of Regulation (EU) 2019/947 (SORA). Confirm with your authority whether it applies SORA 2.0 or 2.5.
1. Ground risk
Aircraft size and maximum speed, plus the population under the flight, give the intrinsic GRC. Strategic mitigations and measures that reduce the effects of impact lower it to the final GRC.
2. Air risk
The airspace sets the initial ARC, from ARC-a (atypical or segregated) to ARC-d (controlled airspace). Restrictions in time, volume or by agreement with air traffic services lower it to the residual ARC.
3. Safety objectives
The SAIL sets how robust each Operational Safety Objective must be: mostly low at SAIL I and II, medium at III and IV, high with third-party validation at V and VI.
4. Levers to lower it
Choose the area and the airspace, size the ground risk buffer, add a demonstrated impact mitigation, and match the aircraft to the mission.
Two things to notice
At ARC-d the SAIL is VI whatever your ground risk, and at ARC-c it never drops below IV. In those columns, work on the air risk pays off more than work on the ground risk.
What you’ll get
The free SAIL levels guide
- The SAIL table explained step by step
- Ground risk and air risk classes in plain language
- What each SAIL demands from your file
- Six levers that move your SAIL down
- Eight checks before you calculate
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How ground and air risk become your SAIL, and how to bring it down.
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FAQ
Questions about SAIL levels
What does SAIL stand for?
Specific Assurance and Integrity Level. It is the output of the SORA risk assessment and tells you and your authority how much confidence the operation needs, which sets the robustness of every Operational Safety Objective.
Which SAIL do most commercial operations get?
Many commercial BVLOS operations over sparsely populated areas in uncontrolled airspace land between SAIL II and SAIL IV, depending on the aircraft and the mitigations claimed.
Can I fly in the Specific category with a final GRC above 7?
No. If the final ground risk class stays above 7, the operation falls into the Certified category and cannot be authorised through SORA.
How can I lower my SAIL?
Reduce ground risk (less populated area, a sized buffer, a demonstrated impact mitigation, a smaller or slower aircraft) or air risk (atypical or segregated airspace, restrictions in time and height, coordination with air traffic services).
What changed with SORA 2.5?
SORA 2.5, introduced with ED Decision 2025/018/R, revised the ground risk model and the safety objectives. The emergency response plan is no longer a ground risk mitigation. Confirm which version your authority applies.
Do I need a full SORA at all?
Not always. If your operation fits a standard scenario (STS) or a pre-defined risk assessment (PDRA), the risk assessment is already done and the file is much lighter. We check this first on every project.
Last updated: October 2026. Sources: Regulation (EU) 2019/947, Article 11 and AMC1 Article 11 (SORA); EASA ED Decision 2025/018/R (SORA 2.5).
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SAIL I to VI explained, with six levers to bring yours down.
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