MidronePro Academy | Drone Laws & Safety | Updated September 2026
STS-02 is one of the most important European regulatory pathways for professional drone operators planning Beyond Visual Line of Sight (BVLOS) operations. It provides a predefined framework for specific BVLOS operations over a controlled ground area in a sparsely populated environment, using a Class C6 unmanned aircraft system (UAS).
For operators working in Spain and across the European Union, understanding STS-02 is increasingly important as professional drone applications expand into infrastructure inspection, surveying, energy, agriculture, environmental monitoring, industrial inspection and autonomous operations.
However, STS-02 is not a general permission to fly BVLOS. The operator must comply with the complete set of requirements defined by the Standard Scenario, including requirements covering the aircraft, pilot competence, operational area, flight geography, contingency procedures, airspace observers, communications, identification and emergency procedures.
For the broader European framework, see our Drone Laws & Safety Guide.
What Is STS-02?
STS-02 is a European Standard Scenario for BVLOS operations with airspace observers over a controlled ground area in a sparsely populated environment.
It belongs to the Specific category of European UAS operations. Unlike Open-category operations, the Specific category covers operations where the risk or operating conditions go beyond the limitations of the Open category.
STS-02 is designed to provide a predefined regulatory pathway for a defined type of BVLOS operation. Instead of creating a completely bespoke operational risk assessment for an operation that fits the scenario, an eligible operator can follow the conditions of STS-02 and submit the required operational declaration to the competent authority.
STS-02 sits within the European Specific category, where operational risk and predefined safety conditions become central to professional BVLOS operations.
Image: MidronePro editorial image illustrating European UAS operations and risk-based planning.
According to EASA, an operation can rely on a Standard Scenario only when all requirements defined by that scenario are satisfied. STS-02 specifically requires the appropriate C6 class identification for the aircraft.
STS-02 vs BVLOS: What Is the Difference?
One of the most common misunderstandings in professional drone operations is treating BVLOS and STS-02 as interchangeable terms.
They are not.
BVLOS describes an operating condition where the remote pilot does not maintain direct visual line of sight with the unmanned aircraft.
STS-02 is one particular European regulatory pathway that permits a defined type of BVLOS operation when all of its conditions are satisfied.
Other BVLOS missions may require a different regulatory route, including an operational authorisation supported by an appropriate risk assessment.
For a broader technical overview, read our BVLOS Drones Guide.
What Are the Main STS-02 Requirements?
STS-02 establishes a specific operating envelope. The most important requirements include:
- BVLOS operation within the defined Standard Scenario.
- A controlled ground area.
- A controlled ground area entirely located in a sparsely populated environment.
- A minimum flight visibility of more than 5 km.
- A Class C6 UAS.
- An active system preventing the unmanned aircraft from breaching the flight geography.
- An active and updated Direct Remote Identification system.
- Appropriately qualified remote pilots.
- The required STS theoretical and practical competence.
- An appropriate operations manual.
- Defined contingency procedures.
- Defined emergency procedures.
- Appropriate arrangements for airspace observers when used.
- A suitable ground risk buffer.
- Compliance with the applicable geographical and airspace requirements.
The actual operation must remain within the complete STS-02 operating envelope. Meeting only some of these conditions does not make an operation compliant with STS-02.
Where Can STS-02 Operations Take Place?
STS-02 operations must take place over a controlled ground area entirely located in a sparsely populated environment.
The controlled ground area includes the operational safety areas associated with the flight geography, contingency area and ground risk buffer.
This requirement is fundamental because STS-02 is not designed as a general-purpose BVLOS framework for densely populated urban environments.
Operators planning BVLOS operations in urban or otherwise unsuitable environments may therefore need to consider another regulatory pathway.
How High Can an STS-02 Drone Fly?
Under the standard STS-02 operating conditions, the unmanned aircraft is generally limited to 120 metres from the closest point of the Earth's surface, subject to the specific provisions and limitations of the applicable regulation.
There are specific provisions concerning operations near artificial obstacles. These provisions should not be interpreted as a general exemption from the normal altitude limitation.
The operator must define and control the operational volume in accordance with the applicable STS-02 requirements and the actual operating environment.
How Far Can an STS-02 Drone Fly?
The maximum permitted distance depends on whether the operation uses airspace observers.
STS-02 With Airspace Observers
When one or more airspace observers are used:
- The unmanned aircraft may be operated no further than 2 km from the remote pilot.
- The unmanned aircraft must be no further than 1 km from the nearest airspace observer.
- The distance between the remote pilot and the airspace observers must comply with the applicable STS-02 limits.
- Reliable communication must be maintained between the remote pilot and the airspace observers.
- The observers must be positioned to provide adequate coverage of the operational volume and surrounding airspace.
EASA's current rules explicitly establish the 2 km remote-pilot limit and the 1 km observer relationship for the observer-based configuration.
STS-02 Without Airspace Observers
The rules also provide a configuration without airspace observers.
In that configuration, the unmanned aircraft must remain within 1 km of the remote pilot. When the aircraft is outside the pilot's VLOS, it must follow a pre-programmed trajectory in accordance with the STS-02 conditions.
This is important because STS-02 does not mean that a remote pilot can simply manually control an aircraft at any arbitrary distance.
Why Are Airspace Observers Important in STS-02?
The airspace observer is an important part of the STS-02 safety architecture.
The observer's role is not simply to watch the drone.
Airspace observers are responsible for helping maintain awareness of surrounding airspace and identifying potential collision risks involving other aircraft.
The operator must therefore consider:
- Observer positioning.
- Coverage of the operational volume.
- Visibility.
- Awareness of surrounding airspace.
- Communications with the remote pilot.
- Identification of potential aircraft conflicts.
- Procedures for unexpected airspace users.
- Emergency communications.
The number and position of observers should be determined according to the operational volume and the ability to maintain the required coverage.
What Is the STS-02 Ground Risk Buffer?
The controlled ground area used for STS-02 includes a flight geography, a contingency area and a ground risk buffer.
The external limits of the contingency area must extend at least 10 metres beyond the limits of the flight geography.
The ground risk buffer must cover at least the distance the aircraft is most likely to travel after activation of the manufacturer's specified means of terminating the flight, taking the operational conditions and manufacturer's limitations into account.
This makes the ground risk buffer an aircraft- and operation-dependent safety consideration rather than simply an arbitrary radius around the flight route.
What Drone Is Required for STS-02?
One of the most important STS-02 requirements is the aircraft classification.
European STS-02 operations require a Class C6 UAS.
The C6 aircraft must comply with the applicable technical requirements and class-identification rules.
AESA likewise identifies C6-class UAS as the aircraft category associated with European STS-02 operations.
The aircraft must also have the required systems for the operation, including:
- An active system designed to prevent the UAS from exceeding the limits of the flight geography.
- An active Direct Remote Identification system.
- The required C6 class identification marking.
- The technical capabilities necessary to conduct the declared operation.
Does a Long-Range DJI Drone Automatically Qualify for STS-02?
No.
This is an important distinction for professional drone buyers.
A drone can have a very long transmission range, advanced obstacle sensing, autonomous flight features, satellite positioning and sophisticated enterprise software without automatically qualifying as a C6 aircraft for STS-02.
Aircraft selection for professional BVLOS operations should therefore begin with the regulatory requirements of the mission, not simply the advertised flight range of the drone.
Operators should verify the actual class identification, conformity documentation and applicable technical requirements before selecting an aircraft for STS-02.
STS-02 Pilot Training Requirements
STS-02 requires specific remote-pilot competence.
A pilot intending to operate under European Standard Scenarios must meet the applicable theoretical and practical training requirements.
AESA confirms that practical STS-02 training covers BVLOS operations over a controlled terrestrial area in a sparsely populated environment using C6-class UAS.
The training framework is designed to ensure that pilots understand not only aircraft control but also the operational environment and safety procedures associated with Standard Scenario operations.
Relevant competence includes subjects such as:
- Operational planning.
- Airspace awareness.
- Risk management.
- Emergency procedures.
- Contingency procedures.
- Aircraft limitations.
- Communications.
- Operational volume management.
- BVLOS-specific procedures.
- Airspace observer coordination.
What Does the STS-02 Operations Manual Need to Cover?
The operations manual is one of the central documents supporting the operation.
It should describe how the operator will conduct missions safely and consistently within the STS-02 framework.
Depending on the operator's structure and mission profile, the manual should address areas such as:
- Roles and responsibilities.
- Aircraft configuration.
- Mission planning.
- Pre-flight procedures.
- Flight geography.
- Contingency area.
- Ground risk buffer.
- Airspace observer procedures.
- Command-and-control procedures.
- Communications.
- Weather limitations.
- Emergency procedures.
- Flight termination procedures.
- Loss-of-link procedures.
- Abnormal situations.
- Post-flight procedures.
- Maintenance and configuration control.
- Occurrence reporting.
The operations manual should be treated as an operational safety document rather than merely a regulatory formality.
STS-02 and Direct Remote Identification
Direct Remote Identification is an important component of the European UAS regulatory framework.
For STS-02, the applicable requirements include an active and updated Direct Remote Identification system.
AESA also confirms that UAS used for practical STS training in STS-02 must have the required DRI system installed and activated.
Remote identification is part of the broader European effort to improve identification and accountability of UAS operating in regulated airspace.
STS-02 and SORA 2.5
STS-02 and SORA 2.5 are not the same thing.
STS-02 is a predefined European Standard Scenario.
SORA, or Specific Operations Risk Assessment, is a risk-assessment methodology used to establish the safety case for certain Specific-category operations.
If an operation fits completely within an applicable Standard Scenario, the operator can use that predefined pathway rather than developing an individual operation under a bespoke SORA process.
If the operation falls outside the STS-02 conditions, another regulatory pathway may be necessary.
For a detailed explanation of the current European risk-assessment framework, read our SORA 2.5 Explained.
STS-02 in Spain: AESA Requirements
For operators registered in Spain, the Agencia Estatal de Seguridad Aérea (AESA) is the relevant national aviation authority for European UAS operations within its competence.
AESA identifies STS-02 as:
BVLOS operations over a controlled terrestrial area in a sparsely populated environment using UAS with Class C6 marking.
Since 1 January 2024, operators wishing to rely on European Standard Scenarios can submit an operational declaration for STS-01 and/or STS-02. AESA states that the operator must first be registered and that the declaration is submitted through the relevant electronic process.
After the required confirmation of receipt and completeness, the declared operation can be started within the limits of the Standard Scenario.
Operators must also verify applicable Spanish geographical zones, airspace restrictions, coordination requirements and other national procedures before conducting a mission.
For a broader Spanish regulatory overview, read our Drone Laws in Spain 2026 guide.
Can STS-02 Be Used in Other EU Countries?
Yes, the European Standard Scenario is designed as an EU-level framework rather than a Spain-only scenario.
EASA explains that the operator submits the declaration to the National Aviation Authority of the Member State where the operator is registered. The declaration can then support operations in other Member States, subject to the applicable cross-border procedures and national requirements.
This is one of the significant advantages of the European Standard Scenario framework for professional operators working across multiple European markets.
However, operators should not assume that a declaration eliminates local airspace restrictions or geographical-zone requirements in the country where the flight takes place.
How to Start an STS-02 Operation
1. Determine Whether the Mission Fits STS-02
Before buying equipment or planning the flight, compare the proposed mission with every STS-02 condition.
2. Register as a UAS Operator
The operator must satisfy the applicable registration requirements in its Member State.
3. Select a C6-Class UAS
Confirm that the selected aircraft genuinely meets the applicable C6 requirements and has the required documentation.
4. Obtain the Required Pilot Competence
The remote pilot must complete the applicable theoretical and practical training requirements for European Standard Scenarios.
5. Develop the Operations Manual
Document normal operations, contingency procedures, emergency procedures and responsibilities.
6. Define the Operational Volume
Establish the flight geography, contingency area and ground risk buffer according to the applicable STS-02 requirements.
7. Establish Airspace Observer Procedures
Where observers are used, define their positioning, responsibilities, communications and operational coverage.
8. Check Airspace and Geographical Zones
Verify the actual location of the proposed operation against current geographical-zone and airspace requirements.
9. Submit the Operational Declaration
Submit the applicable STS-02 operational declaration to the competent authority according to the applicable national process.
10. Operate Strictly Within the Declared Conditions
Every flight must remain within the conditions of the applicable Standard Scenario and any other restrictions applicable to the location.
STS-02 Operational Requirements at a Glance
| Requirement | STS-02 Requirement |
|---|---|
| EU category | Specific category |
| Operation | BVLOS |
| Environment | Sparsely populated |
| Ground area | Controlled ground area |
| UAS class | C6 |
| Minimum flight visibility | More than 5 km |
| Maximum standard operating height | 120 m from the closest point of the Earth's surface, subject to applicable provisions |
| Distance with observers | Up to 2 km from the remote pilot, subject to all STS-02 conditions |
| Distance to nearest observer | Up to 1 km |
| Distance without observers | Up to 1 km from the remote pilot |
| Remote identification | Active and updated Direct Remote Identification |
| Flight geography protection | Active system required to prevent breach |
| Ground risk buffer | Based on expected post-flight-termination travel distance and operating conditions |
| Pilot | Required STS theoretical and practical competence |
| Operator documentation | Operations manual and applicable operational declaration |
Best Professional Use Cases for STS-02
Infrastructure Inspection
Linear infrastructure can be particularly suitable for structured BVLOS missions. Roads, pipelines, rail corridors and utility infrastructure can benefit from repeatable drone inspection workflows when the operating environment satisfies STS-02.
Renewable Energy
Solar farms and other renewable-energy infrastructure increasingly rely on drones for inspection and data collection. BVLOS can potentially increase the coverage and efficiency of these missions where the regulatory conditions are satisfied.
Surveying and Mapping
Large-area mapping operations can benefit from repeatable automated routes. STS-02 can provide a predefined framework for certain professional BVLOS missions, subject to the operating environment and all scenario limitations.
Agriculture
Large agricultural areas may benefit from longer-range monitoring and mapping operations, particularly where the operational area can be controlled and the mission remains within the STS-02 envelope.
Environmental Monitoring
Professional environmental surveys may benefit from repeatable BVLOS routes across large areas, provided that population, airspace, visibility and other operational conditions remain compliant.
Industrial Inspection
Remote industrial assets can represent another important BVLOS application, particularly when repeatable flight routes and controlled operational areas can be established.
STS-02 vs a Bespoke BVLOS Authorisation
The major advantage of STS-02 is predefined regulatory conditions.
An operation that fully satisfies the Standard Scenario can use the STS pathway rather than developing a completely bespoke safety case.
But there is an important trade-off.
The operator must remain within the boundaries of STS-02.
If the mission requires operating outside the scenario's aircraft, geographical, population, altitude, distance or other requirements, STS-02 cannot simply be stretched to accommodate it.
The operator may instead need to use another Specific-category pathway, potentially involving a risk assessment and operational authorisation.
Common STS-02 Mistakes
Assuming BVLOS Means Unlimited Range
STS-02 provides a defined BVLOS operating envelope. It does not provide unlimited range.
Choosing a Drone Based Only on Flight Range
A long-range drone is not automatically an STS-02 drone. The C6 requirement is critical.
Ignoring the Operational Area
The operation must take place over a controlled ground area in a sparsely populated environment.
Using Unqualified Airspace Observers
Observers need to understand their responsibilities and must be positioned to provide the required coverage.
Ignoring the Ground Risk Buffer
The ground risk buffer must reflect the aircraft's expected behaviour following activation of the manufacturer's flight-termination means.
Assuming FPV Goggles Create BVLOS Permission
FPV equipment does not automatically create a legal BVLOS operation. The applicable regulatory pathway remains decisive.
Ignoring Local Airspace Restrictions
A European Standard Scenario does not eliminate geographical-zone or airspace restrictions applicable at the actual flight location.
Using Outdated Regulatory Information
UAS regulation continues to evolve. Operators should always verify the current EASA rules and national aviation-authority guidance before conducting professional BVLOS operations.
STS-02, Detect and Avoid and the Future of BVLOS
Detect-and-Avoid technology is becoming increasingly important as professional BVLOS operations become more sophisticated.
Image: MidronePro article image from the Detect and Avoid Technology for BVLOS guide.
STS-02 represents an important step toward more sophisticated commercial BVLOS operations, but the future of BVLOS will extend well beyond the relatively defined STS-02 operating envelope.
Professional drone systems are increasingly combining:
- Autonomous flight.
- Drone-in-a-Box systems.
- Cellular connectivity.
- Advanced command-and-control systems.
- Detect-and-Avoid technology.
- AI-assisted perception.
- U-space services.
- Automated mission management.
- Advanced operational risk management.
For a deeper technical analysis, read our Detect and Avoid Technology for BVLOS guide.
What STS-02 Means for Professional Drone Businesses
For commercial drone companies, STS-02 is more than a regulatory acronym.
It represents a structured route toward integrating BVLOS capability into repeatable professional operations.
Companies that understand STS-02 can begin designing their aircraft procurement, pilot training, operating procedures, mission planning and safety management around the requirements of advanced UAS operations.
This is particularly important for sectors such as:
- Renewable energy.
- Oil and gas.
- Infrastructure.
- Utilities.
- Rail.
- Construction.
- Surveying.
- Agriculture.
- Environmental monitoring.
- Industrial inspection.
The key lesson is that successful BVLOS operations require the integration of technology, people, procedures and regulatory compliance.
Important regulatory disclaimer: This article is provided for educational and informational purposes and does not constitute legal, aviation or regulatory advice. UAS regulations, geographical zones, airspace restrictions and national procedures can change. Before conducting an STS-02 or other BVLOS operation, operators should verify the current requirements with EASA and the competent National Aviation Authority, including AESA in Spain where applicable.
Learn More at MidronePro Academy
Continue exploring BVLOS, European drone regulation and advanced professional UAS technology:
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FAQ about STS-02 BVLOS in Europe
What Is STS-02?
STS-02 is a European Standard Scenario for BVLOS operations with airspace observers over a controlled ground area in a sparsely populated environment using a C6-class UAS.
Can STS-02 Be Used for BVLOS Operations?
Yes. STS-02 is specifically designed for certain BVLOS operations, subject to the complete set of Standard Scenario requirements.
What Drone Class Is Required for STS-02?
STS-02 requires a UAS bearing the appropriate Class C6 identification label and complying with the applicable C6 requirements.
How Far Can You Fly Under STS-02?
When airspace observers are used, the aircraft may be operated up to 2 km from the remote pilot and no more than 1 km from the nearest airspace observer, subject to the complete STS-02 conditions. Without an airspace observer, the aircraft must remain within 1 km of the remote pilot and comply with the applicable pre-programmed trajectory requirement when outside VLOS.
Is STS-02 Available in Spain?
Yes. AESA applies the European Standard Scenario framework in Spain. Operators registered in Spain can rely on STS-02 after meeting the applicable requirements and submitting the required operational declaration.
Do I Need Special STS-02 Pilot Training?
Yes. Remote pilots operating under European Standard Scenarios must meet the applicable theoretical knowledge and practical competence requirements. AESA specifically provides STS-02 practical training for BVLOS operations with C6-class UAS.
Does STS-02 Require Airspace Observers?
STS-02 is designed around BVLOS operations with airspace observers, but the regulatory framework also defines operating conditions for a configuration without airspace observers, including a shorter maximum distance from the remote pilot and a pre-programmed trajectory when the aircraft is outside VLOS.
Can Any DJI Drone Be Used for STS-02?
No. The aircraft must satisfy the applicable C6 requirements. A drone's advertised range, autonomy or enterprise status does not automatically establish STS-02 eligibility.
Does STS-02 Replace SORA?
No. STS-02 is a predefined Standard Scenario, while SORA is a broader risk-assessment methodology that may be relevant when an operation does not fit an applicable predefined regulatory pathway.
Does STS-02 Allow Unlimited BVLOS Flight?
No. STS-02 establishes specific limits covering the operational area, aircraft class, altitude, visibility, distance, pilot competence, containment, identification, procedures and other safety requirements.
Where Should I Check the Current STS-02 Rules?
Operators should consult the latest EASA Easy Access Rules for Unmanned Aircraft Systems and the guidance of the relevant National Aviation Authority. In Spain, operators should also consult the current AESA UAS requirements and procedures.
