PDRA01 vs UK SORA: Which drone authorisation is best?

• Understand the UK drone regulatory framework under the CAA;

• Learn the key differences between the two main Operational Authorisation pathways, PDRA01 and UK SORA, including what they enable, limitations, and typical use cases;

• Discover how heliguy™ can support organisations with training, consultancy, and Operational Authorisation applications.

As drone operations expand across industries such as infrastructure inspection, surveying, and public safety, organisations increasingly need to navigate the UK’s regulatory framework.

For many operations that fall outside the Open Category, pilots operating in the Specific Category must apply for Operational Authorisation from the Civil Aviation Authority (CAA). Two common pathways are Pre-Defined Risk Assessment 01 (PDRA01) and the UK Specific Operations Risk Assessment (UK SORA).

This article explains how PDRA01 and UK SORA differ, the types of operations each pathway supports and how heliguy™ supports along the process.

Key takeaways

• The UK drone regulatory framework divides operations into Open, Specific, and Certified categories based on operational risk.

• Many drone missions fall into the Specific Category, which requires Operational Authorisation from the CAA.

• PDRA01 provides a standardised risk assessment for common VLOS operations within predefined safety limits.

• UK SORA enables more complex or higher-risk missions such as BVLOS operations, replacing the previous OSC framework in 2025.

• heliguy™ provides training and consultancy services to assist organisations obtain the appropriate Operational Authorisation.

PDRA01 vs UK SORA at a glance

The table above provides a quick overview of the key differences between PDRA01 and UK SORA. More details will be explained in following sections.

Understanding UK drone regulatory framework

Drone operations in the UK are regulated by CAA and follow a risk-based framework. Most drone operations fall into either the Open Category or the Specific Category, depending on the level of operational risk involved.

Open Category

The Open Category covers low-risk drone operations that can be conducted without prior authorisation from the CAA.

Operators in the Open Category do not need Operational Authorisation, provided they remain within the predefined limitations.

Typical Open Category requirements include:

• Visual Line of Sight (VLOS) operations

• Smaller drones and limited operational complexity

• Minimum distances from uninvolved people

• No flights over crowds

The Open Category is divided into three sub-categories: A1, A2, and A3, which determine how close you can fly to people and the type of drone you can operate. For example, A1 allows flights closer to people with lighter drones, while A3 allows heavier drones but requires greater separation from people and built-up areas.

Specific Category

The Specific Category applies to operations that present higher levels of risk than those allowed in the Open Category.

Operators in the Specific Category must obtain Operational Authorisation from the CAA before conducting flights. This authorisation demonstrates that the operator has assessed potential risks and implemented appropriate safety measures.

There are two main pathways used to obtain Operational Authorisation:

• PDRA01 (Pre-Defined Risk Assessment)

• UK SORA (Specific Operations Risk Assessment)

Why it matters

Understanding the UK drone regulatory framework is important for organisations planning drone operations.

As many missions fall into the Specific Category, choosing the correct pathway ensures organisations to conduct drone missions safely, legally, and within the CAA’s framework.

What is PDRA01?

PDRA01 stands for Pre-Defined Risk Assessment 01.

It is a framework developed by CAA that allows drone operators to obtain Operational Authorisation for certain types of operations in the Specific Category.

PDRA01 provides a standardised set of conditions and mitigations that operators can follow. This simplifies the application process for operations that fall within predefined safety parameters.

What you can do with a PDRA01

PDRA01 enables operators to:

Fly aircraft below 25kg within 150m of any residential, commercial, industrial, and/or recreational areas within visual line of sight (VLOS).

Key limitations of PDRA01

The parameters of a PDRA01 ensure the operation remains within acceptable risk levels defined by the CAA. As such, there are some important rules to abide by, including:

• Keep the drone within 120 metres (400ft) from the earth's closest point.

• Flights must be VLOS.

• Flights must not be carried out within 50m of uninvolved persons, except during take-off and landing, where this separation may be reduced to 30m.

• Any overflight of uninvolved people must be kept to a minimum.

• Flights must not be carried out within 50m horizontal separation of assemblies of people. Any overflight of assemblies of people must not be conducted.

For operations not covered by PDRA01, organisations will need to apply for an Operational Authorisation using UK SORA.

Typical PDRA01 operations

Common PDRA01 use cases include:

• Roof inspections

• Property photography

• Construction site monitoring

• Infrastructure inspection

• Surveying buildings and facilities

These operations often occur in built environments where Open Category rules would otherwise restrict flights, particularly for operations outside the A1 sub-category.

How to obtain a PDRA01

For a PDRA01 authorisation, pilots need:

• Valid Flyer ID and Valid Operator ID. Click here to find out more.

• Valid RPC-L1 (Level 1 Remote Pilot Certificate) or a GVC (General Visual Line of Sight Certificate).

• Have at least two hours of flying experience in the previous three months. This experience must be gained on similar and/or equivalent UAS to the UAS that will be used under PDRA01 Operational Authorisation.

• Valid insurance.

• Operations Manual.

• Remote Pilot’s Logbook.

• Operator's aircraft technical logbook.

Read more details on how to obtain a PDRA01 Operational Authorisation.

What is UK SORA?

UK SORA is a more detailed risk assessment used for operations that fall outside predefined scenarios, including more complex or higher-risk missions.

UK SORA was introduced on 23 April 2025, replacing the previous Operating Safety Case (OSC) method. The change was intended to create a more standardised, transparent, and consistent approach to risk assessment. Read more on how UK SORA differs from OSC.

Key elements in UK SORA

UK SORA evaluates operational risk using several key components:

• Ground Risk: the risk of the drone hitting a person on the ground and causing a fatality. Ground Class Risk (GRC) may range from GRC1 to GRC7, with 7 being the highest.

• Air Risk: the risk of a mid-air collision between the drone and a manned aircraft. Air Risk Class (ARC) can range from ARC-a to ARC-d, with ARC-d being the highest.

• SAIL (Specific Assurance and Integrity Level): the overall risk of the operation, from 1 (lowest risk) to 6 (highest risk). SAIL levels are determined by GRC and ARC.

Operations that require a UK SORA

Examples of operations that require a UK SORA-based operational authorisation include:

• Dropping items from your drone.

• Flying beyond visual line of sight (BVLOS). This type of operation is often supported by advanced ecosystems such as the DJI Dock range, which enable automated and remote drone deployments for persistent or large-area operations (see our DJI Dock collection).

• Flying with drones weighing 25kg or more. In these cases, operators may consider heavy-lift platforms such as the DJI FlyCart 30 or FlyCart 100 (see our DJI FlyCart Series), which are designed for complex logistics operations. For further insight, explore our recent FlyCart 30 case study, where we supported Aureos in securing heavy-lift permissions.

• Flying close to crowds.

• Flying close to people with aircraft that weigh 500g or more.

• Flying at increased heights above ground level.

• Swarm operations.

• Flying more than 120m (400ft) above ground level.

Key limitations of UK SORA

UK SORA covers most but not all operations that could be carried out in the Specific Category.

Operations that are permitted in the Specific Category, but are outside the policy limits of UK SORA include:

• Operating unmanned aircraft with a dimension larger than 40 metres.

• Operating unmanned aircraft with a maximum cruise speed above 200 metres per second.

• Operations above Flight Level 660 (FL660).

• Operating unmanned aircraft with a maximum dimension of more than 3 metres or maximum speed over 35 metres per second, where the population density is greater than 50,000 people per km^2.

Certain missions, such as those requiring airspace changes or the transport of dangerous goods, require additional regulatory approvals outside UK SORA.

The UK SORA Application Service cannot be used for operations that fall outside the Specific Category, such as those regulated under the Certified Category.

How to obtain a UK SORA

Operators can apply for a UK SORA authorisation using the UK SORA-based Application Service, which provides a structured process for submitting the required risk assessment to the CAA.

As part of the application, operators must assess factors such as ground risk, air risk, and the resulting SAIL level, and provide supporting operational and safety documentation.

For SORA-based operations, remote pilots are typically required to hold an appropriate competency qualification, such as the General Visual Line of Sight Certificate (GVC), Level 1 Remote Pilot Certificate (RPC-L1), or Level 2 Remote Pilot Certificate (RPC-L2), depending on the operation.

Once approved, the Operational Authorisation is valid for 12 months. Operators can submit a renewal application up to 28 days before the authorisation expires.

How heliguy™ supports organisations with Operational Authorisation

heliguy™ has an in-house training team and regulatory department to help organisations obtain and maintain Operational Authorisation in the UK Specific Category.

Support for PDRA01 operations

For organisations operating under PDRA01, heliguy™ supports pilots and operators with the training and documentation required to remain compliant.

Support includes:

• GVC training to help pilots obtain the qualification required.

• Operations Manual Renewal Service to ensure documentation remains compliant with CAA requirements.

• Drone Maintenance Training to help operators understand their legal responsibilities and perform basic maintenance tasks required for PDRA01 compliance.

Support for UK SORA operations

For organisations conducting more complex operations, heliguy™ provides regulatory consultancy and advanced operational training.

Support includes:

• UK SORA consultancy from heliguy™’s in-house regulatory specialists to help prepare and secure Operational Authorisation.

• BVLOS training, including operations supported by Visual Observers (VOs), to support advanced drone operations.

• Assistance with risk assessment preparation and regulatory documentation.

Summary

PDRA01 and UK SORA are two pathways used to obtain Operational Authorisation in the UK Specific Category, each designed for different types of drone operations.

Selecting the appropriate pathway ensures operations remain compliant with CAA regulations while allowing operators to conduct missions safely and effectively.

heliguy™ provides training and regulatory guidance for organisations to obtain the necessary authorisation and scale drone operations within the UK regulatory framework.

To find out more about how heliguy™ can help you navigate the authorisation process, contact us.