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SORA 2.5 Methodology — Specific Operation Risk Assessment

Table of Contents
After a few years using the SORA 2.0 methodology published by JARUS, the European Aviation Safety Agency (EASA) has announced that it will develop an update of the methodology, introducing SORA 2.5. This update introduces a quantitative definition of ground risk assessment and makes a general revision of the text to simplify the language and make it easier to understand.

For more information on the 2.0 methodology, see our article.

These are the main modifications:

Description of the operation

The output of the SORA is expected to consist of 3 sets of documents:

Operations Manual

This shall include the procedures to be used by the operator’s personnel to perform the operation safely.. The content will be based on OSO implementation, mitigation, and containment.

Evidence of compliance

All requirements for an adequate level of robustness must be justified. Evidence of compliance will vary depending on the level of assurance required.


SORA Safety Case

It is a description of how the operator has performed the SORA describing all the steps.

Step #1 is to gather all the information to complete the documents described when all the SORA steps are completed.

Ground Risk (GRC)

This is one of the steps that has undergone a major change, as a new risk ground class table has been introduced.

Population density maps will be used, considering the fluctuations that occur at different times of the year and day. For example, during the day, business centres will have a higher density than at night, whereas in residential areas, the situation will be the opposite.

Intrinsic ground risk class
Maximum UA characteristic dimension 1 m 3 m 6 m 20 m 40 m
Maximum cruising speed 25 m/s 35 m/s 75 m/s 250 m/s 200 m/s
Maximum population density of the IGRC
Ground Controlled Area 1 2 3 4 5
< 25 3 4 5 6 7
< 250 4 5 6 7 8
< 2.500 5 6 7 8 9
< 25.000 6 7 8 9 10
< 250.000 7 8 9 10 11
>250.000 7 9 Category C Operations (Not part of SORA)

In addition, this step includes the identification of the size of the adjacent area and its risk class.

Ground Risk Mitigations

The mitigation measures applicable to the reduction of the risk class value on ground, established in the previous section, have been updated.

Air Risk Class (ARC)

In this case, Step#4 has not been modified, but some terms have simply been clarified for better understanding, such as the meaning of atypical airspace and the determination of the size of adjacent airspace.

OSO - Operational Security Objectives

It has been relocated in the new SORA 2.5 as Step#9.

The list of OSOs, i.e. Operational Security Objectives, has been restructured, although the content has not been changed.

Area and adjacent space

It has been relocated in the new SORA 2.5 as Step#8.

Just like Step #2, this is one of the points that has implemented the most changes. This step defines how to calculate the size of the adjacent airspace, for the determination of the associated risk, calculated through the population density.

Safety report

Finally, this section clarifies that, at this step, the operator is expected to have collected all evidence of compliance and developed the necessary documentation.

If you need us to manage risk assessments so that you can fly in new scenarios, do not hesitate to check our services.

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