The adoption of drones for critical infrastructure inspection across Europe is revolutionizing how we maintain vital assets, from towering wind turbines to sprawling bridge networks. These Unmanned Aircraft Systems (UAS) offer unprecedented efficiency, safety, and data accuracy, making them indispensable tools for modern asset management. However, unlocking this potential requires a clear understanding of the stringent regulatory landscape established by the European Union Aviation Safety Agency (EASA). Aspiring drone operators in the infrastructure sector must navigate EASA’s risk-based framework to ensure full compliance, secure appropriate licensing, and conduct safe, legal, and effective operations.
EASA’s Risk-Based Approach to Drone Operations
EASA’s drone regulations, particularly EU Regulations 2019/947 and 2019/945, came into force on December 31, 2020, establishing a harmonized framework across all EU member states. These regulations classify drone operations into three primary categories based on the level of risk involved: Open, Specific, and Certified. This risk-based approach ensures that regulatory burdens are proportionate to the potential dangers posed by the operation.
The Open Category: Low-Risk Operations
The Open category is designed for operations that present a low or no risk to third parties, encompassing many recreational and some commercial activities. Operations in this category do not require prior operational authorization from a National Aviation Authority (NAA) but must adhere to strict limitations:
- The drone must have a maximum take-off mass (MTOM) of less than 25 kg.
- Operations must remain within the visual line of sight (VLOS) of the remote pilot, or with an observer maintaining VLOS in close and effective communication with the pilot.
- The maximum flight altitude is generally limited to 120 meters above the surface.
- Drones should not be flown over uninvolved people, and never over assemblies of people.
- Drones must bear a CE class identification label (C0, C1, C2, C3, or C4) or be privately built under 25 kg.
The Open category is further divided into three subcategories:
- A1: Allows flight over uninvolved people, but not over crowds, with drones up to 900g (C0/C1 class drones or privately built under 250g). Flying over uninvolved people should be avoided whenever possible.
- A2: Permits operations closer to people than A3, but not over them. Requires a horizontal safety distance of at least 30 meters from uninvolved persons, which can be reduced to 5 meters if the drone has a low-speed mode (typically for C2 class drones up to 4 kg).
- A3: Requires the drone to be flown far from people and at a horizontal distance of at least 150 meters from residential, commercial, industrial, or recreational areas (for C3/C4 class drones up to 25 kg or privately built up to 25 kg).
For many basic infrastructure inspections in unpopulated or sparsely populated areas, elements of the Open category, particularly A3, might be applicable, provided all limitations are met.
The Specific Category: Medium-Risk Operations
When an operation falls outside the limitations of the Open category, it moves into the Specific category. This is often the case for more complex infrastructure inspections, such as those involving:
- Beyond Visual Line of Sight (BVLOS) operations.
- Flights at heights exceeding 120 meters (e.g., inspecting tall structures).
- Operations in urban environments with heavier drones or without a class identification label.
- Operations over controlled ground areas that may include populated areas.
To operate in the Specific category, drone operators generally require an operational authorization from their National Aviation Authority (NAA). This authorization is typically obtained through one of three pathways:
Standard Scenarios (STS)
EASA has defined Standard Scenarios (STS) for common types of higher-risk operations that have a predefined risk assessment and mitigation measures. If an infrastructure inspection operation fits within an STS (e.g., STS-01 or STS-02), the operator can submit a declaration to the NAA, and upon confirmation of completeness, can proceed with the operation using a C5 or C6 class drone. STS-01 covers operations over a controlled ground area in a populated area, while STS-02 focuses on sparsely populated areas.
Pre-Defined Risk Assessments (PDRA)
For operations not covered by Standard Scenarios, operators may use a Pre-Defined Risk Assessment (PDRA) provided by EASA. These PDRAs outline specific conditions and mitigations for certain types of operations. EASA has developed PDRAs specifically for linear inspections, including BVLOS operations, and for surveillance and inspection of facilities and infrastructures where the UA flies very close to them, sometimes below 30m or in atypical airspace.
Specific Operations Risk Assessment (SORA)
If neither an STS nor a PDRA is suitable, the operator must conduct their own Specific Operations Risk Assessment (SORA). The SORA methodology is a comprehensive framework to assess the risks of a proposed drone operation and define appropriate mitigation measures. This detailed assessment is then submitted to the NAA for operational authorization.
The Certified Category: High-Risk Operations
The Certified category is reserved for the highest-risk operations, such as transporting passengers or dangerous goods, or operations involving large drones over concentrations of people, requiring certification of the drone, the operator, and in some cases, the remote pilot. Infrastructure inspection operations are unlikely to fall into this category unless they involve exceptionally large UAS or novel concepts involving significant risk to third parties.
Key Regulatory Requirements for Drone Operators
Regardless of the operational category, certain fundamental requirements apply to drone operators and remote pilots engaging in infrastructure inspection.
Drone Operator Registration
All drone operators (not individual drones) of UAS weighing 250 grams or more, or any drone equipped with a camera or other sensor capable of detecting personal data (unless it’s a toy), must register with the National Aviation Authority of the EU country they reside in. Upon registration, the operator receives a unique drone operator ID number, which must be affixed visibly to all drones they own. This registration is valid for a period defined by the NAA, after which it needs to be renewed.
Remote Pilot Competency and Training
The remote pilot operating the drone must possess the appropriate level of competency and certification for the intended operation.
Open Category Training: A1/A3 and A2 Certificates
- A1/A3 Certificate: For flying in subcategories A1 and A3, pilots must complete an online training course and pass an online theoretical exam covering subjects like air safety, airspace restrictions, aviation regulation, human performance limitations, operational procedures, UAS general knowledge, privacy, data protection, insurance, and security.
- A2 Remote Pilot Certificate: To fly in subcategory A2, in addition to the A1/A3 certificate, pilots need to conduct a practical self-training and pass an additional theoretical exam at a recognized testing center. This exam focuses on meteorology, UAS flight performance, and technical and operational mitigations for ground risk.
Remote pilot competency certificates for the Open category are generally valid for 5 years and are recognized across all EASA member states.
Specific Category Training
For the Specific category, the required training and competency are more extensive and are tailored to the complexity and risks of the operation.
- Standard Scenarios (STS): Pilots operating under STS-01 or STS-02 require specific theoretical knowledge and practical skill assessments relevant to these scenarios.
- Operational Authorization (SORA/PDRA): For operations requiring an operational authorization based on a SORA or PDRA, the training will be outlined in the authorization issued by the NAA, ensuring the pilot has the necessary skills for the specific risks involved. EASA has updated guidance to include new Acceptable Means of Compliance (AMC) with training for pilots operating in the ‘specific’ category.
Other Important Considerations
- Geographical Zones and Airspace Restrictions: Operators must always consult airspace maps and be aware of geofencing requirements to avoid restricted areas like airports or military zones. National Aviation Authorities publish information on geographical zones.
- Insurance: Most EASA Member States mandate third-party insurance for drone operations, particularly for commercial activities.
- U-Space Integration: The U-Space framework is being developed to facilitate the safe integration of drones into shared airspace, using digital tools for traffic management and collision avoidance.
- Drone Class Identification Labels: As of January 1, 2024, the use of class-certified drones became more prevalent, especially for Open category flying. Drones placed on the market before this date without a class label are considered “legacy drones” and have specific operational conditions.
Infrastructure Inspection Specifics
Infrastructure inspection using drones often involves flying near critical structures, sometimes at varying altitudes and potentially in complex environments.
- Linear Inspections and BVLOS: Inspections of linear infrastructure (e.g., pipelines, power lines, railways) may benefit greatly from BVLOS operations. EASA has specifically developed Predefined Risk Assessments (PDRAs) for Beyond Visual Line Of Sight (BVLOS) operations for linear inspections, indicating a clear regulatory path for such activities in the Specific category.
- Close Proximity Operations: Inspecting infrastructure often requires close proximity to the asset. This might push operations from the A3 subcategory into A2 (with specific distance rules from people) or more likely into the Specific category if flight over uninvolved people, complex environments, or other factors are involved. EASA has facilitated authorizations for surveillance and inspection of facilities and infrastructures, with the UAS flying very close to them, through PDRA G-03, even in atypical airspace or below 30m.
- Data Protection and Privacy: Drones equipped with cameras collecting data during inspections must adhere to privacy and data protection regulations, especially if personal data is captured.
Conclusion
The European regulatory framework for drone operator licensing provides a structured approach to ensure the safe and responsible use of UAS for applications like infrastructure inspection. While basic inspection tasks in open, unpopulated areas might fall under the Open category with online training and registration, more complex or higher-risk operations—especially those involving BVLOS, urban environments, or specific proximities to people and structures—will necessitate operational authorizations under the Specific category. This typically involves detailed risk assessments (SORA or PDRA) and more advanced remote pilot competency certificates. Operators must register with their national authorities, ensure their pilots are adequately trained and certified, and remain vigilant about airspace restrictions and drone-specific requirements to leverage the full potential of drone technology for efficient and safe infrastructure inspection across Europe.
