This page gives a brief overview of key concepts in UK SORA.
You should make sure you're familiar with the full UK SORA policy before you apply for an authorisation.
Full details are in UK Regulation (EU) 2019/947 Article 11 (opens in a new tab).
It's free to calculate your SAIL and containment levels
It's free to use the UK SORA-based Application Service to calculate your SAIL and containment levels.
This can be a good way to explore different options for your proposed operations.
You only pay if you submit your application.
You must have an Operator ID before you start.
Preparing the information you need to work out your SAIL and containment levels.
Operational volume
The location of your operations is called the operational volume.
The operational volume is made up of:
· the flight volume: the area where you plan to operate
· the contingency volume: an area around the flight volume, where you must perform contingency procedures if you enter
There are other important areas, called the ground risk buffer and adjacent area.
Working out your operational volume and related areas > (opens in a new tab)
You can apply for an operational authorisation that covers a single geographical location, geographical locations that share the same characteristics, or multiple locations.
How UK SORA considers risks
UK SORA considers the 2 aspects of operational safety risk:
- ground risks
- air risks
Ground Risk Class (GRC)
Your Ground Risk Class (GRC) is the risk of your unmanned aircraft hitting a person on the ground and causing a fatality.
Your final GRC may range from GRC 1 (lowest risk) to GRC 7 (highest risk).
Ground risk mitigations
You can reduce your GRC using certain ground risk mitigations, such as sheltering.
Working out your ground risk (opens in a new tab) >
Air Risk Class (ARC)
Your Air Risk Class (ARC) represents the risk of a mid-air collision (MAC) between your unmanned aircraft and manned aircraft.
Your ARC may range from ARC-a (lowest risk) to ARC-d (highest risk).
Air risk mitigations
You can reduce your ARC using certain air risk mitigations, including carrying out your operations using VLOS.
Working out your air risk (opens in a new tab) >
You can apply for an operational authorisation that covers unmanned aircraft with different characteristics.
SAIL level
Your SAIL level represents the overall risk of your operation, from 1 (lowest risk) to 6 (highest risk).
Your SAIL level is determined by your GRC and ARC.
Your SAIL level is important as it determines the Operational Safety Objectives (OSO)s and other requirements you'll need to comply with before we can grant your operational authorisation.
SAIL stands for Specific Assurance and Integrity Level.
Working out your SAIL level. (opens in a new tab).
Containment level
Your containment level determines the technical and operational mitigations you must put in place to contain your flight within the operational volume and ground risk buffer.
Your containment level is driven by your SAIL level and the ground risk in the adjacent area.
Working out your containment level (opens in a new tab) >
Operational Safety Objectives (OSO)s and containment requirements
Operational Safety Objectives (OSOs) are requirements that you must meet when carrying out your operations.
Your SAIL level determines the set of OSOs you must meet and the level of robustness you must meet them at.
Robustness is a combination of:
- integrity: how good a requirement is at reducing a risk
- assurance: the degree of certainty that applies to the level of integrity
Robustness may be low, medium or high.
Containment requirements and ground risk mitigations also have levels of robustness.
Containment requirements are similar to OSOs but are determined by your ground risk in the adjacent area as well as your SAIL level.
Working out your Operational Safety Objectives (OSOs) >
Compliance approach and compliance evidence
You compliance approach is how you choose to comply with a regulation, requirement or standard.
Your compliance evidence is how you demonstrate that you comply. Common examples of compliance evidence include flight logs, technical data sheets, flight tests, and design specifications.