If you work with drones and the job no longer fits in the open category, sooner or later two acronyms show up: STS-01 and STS-02. They are the two European standard scenarios, and almost everyone who gets this far asks the same question: which one do I actually need?
The short answer depends on two things: whether you will keep the drone in sight the whole time, and whether you fly near populated areas. The long answer is this article, which explains what each scenario allows, what it asks of the pilot, the drone and the operator, and how to choose without paying for training you will not use. It is written for the Spanish system, where AESA is the authority.
If what you want is study material, you will find it in the STS-01 and STS-02 syllabus in PDF, free to download. This piece deals with the decision that comes before studying: what each scenario is for.
Not sure yet which one you need?
Tell us what work you want to do and we will tell you whether one scenario is enough or you need both. The STS certificate course prepares the two of them.
What a standard scenario is and why it exists
The European framework, Implementing Regulation (EU) 2019/947, sorts drone operations into three categories: open, specific and certified. The open category is the low-risk one and requires no operational paperwork. As soon as a job needs something the open category does not allow —getting close to people, flying without seeing the drone, using heavier equipment— you are in the specific category, and there the general rule is to apply for an operational authorisation with its risk assessment.
Standard scenarios are the shortcut. They describe operations whose risk was already assessed when the rule was written, so the operator does not apply for an authorisation: it submits a declaration to the national authority. According to EASA, once the authority confirms receipt and completeness, the operation can start. Both scenarios are set out in Appendix 1 to Regulation 2019/947 (introduced by Implementing Regulation (EU) 2020/639) and can be declared since 1 January 2024.
The price of the shortcut is rigidity. The scenario covers exactly what it describes and nothing else. If a single condition of your operation falls outside the script, you are no longer under an STS and you are back to an authorisation.
STS-01: drone in sight, populated environment
This is the scenario for urban work and operations close to people. Its main conditions:
- Always within visual line of sight (VLOS): the pilot sees the drone at all times.
- Maximum height of 120 metres.
- Over a controlled ground area, meaning the area where the operator can ensure that only people involved in the operation are present.
- That area may be in a populated environment: this is what sets it apart from the other scenario.
- With a class C5 drone: maximum take-off mass up to 25 kg and characteristic dimension up to 3 metres.
The typical job here is done in town or next to buildings: façade and roof surveys, monitoring construction in a city centre, a shoot on a closed street. What makes STS-01 hard is rarely the flight itself but controlling the ground: cordoning off the area, making sure no outsider walks in and, in practice, reaching an agreement with whoever manages that space. It is preparation work nobody sees, and it is billable.
STS-02: beyond sight, away from people
This is the scenario for long, linear jobs, where keeping the drone in sight the whole time would make the operation unworkable:
- It allows flight beyond visual line of sight (BVLOS).
- The drone stays within 1 km of the pilot without observers, or up to 2 km with airspace observers.
- Maximum height of 120 metres.
- Over a controlled ground area located entirely in a sparsely populated environment.
- With a class C6 drone, with the same mass and size limits as the C5.
Power lines, canals, large farms and linear works fit here. They are the jobs we describe in drone inspection work and in drone surveying and photogrammetry, where beyond-sight flight appears as soon as the stretch gets longer.
The two side by side
| STS-01 | STS-02 | |
|---|---|---|
| Drone visibility | Always in sight | May fly out of sight |
| Distance from pilot | Visual line of sight | Up to 1 km, or 2 km with observers |
| Environment | May be populated | Sparsely populated |
| Ground area | Controlled | Controlled |
| Maximum height | 120 m | 120 m |
| Drone class | C5 | C6 |
What it asks of you as a pilot
The pilot side takes three steps, all of them described by AESA on its standard scenario training page.
First, the open category base. The STS exam builds on it: with the A1/A3 certificate the exam has 40 questions in 40 minutes; with the A2 certificate, 30 questions in 30 minutes. If you are still at that point, which drone licence category you need explains it from the start.
Second, the theory exam before AESA. You register on AESA’s electronic office and sit the exam online, remotely proctored: webcam, microphone and screen sharing. You need at least 75 % correct answers, and each registration gives you two attempts. The theory is the same for both scenarios.
Third, practical training for each scenario. This is where they split: STS-01 practical training does not count for STS-02, and vice versa. It is delivered by entities recognised by AESA or by operators that have declared to AESA, with continuous assessment that ends in the accreditation of practical skills for that scenario.
A detail people forget: the theory certificate does not last forever. AESA runs a revalidation procedure for STS theory certificates, so note the date.
If you held a Spanish STS-ES certificate
Spain’s national scenarios, the STS-ES, can no longer be used to declare operations: since 1 January 2026 only the European ones apply. AESA keeps open the conversion of STS-ES pilot certificates to the European STS, with no deadline. If that is your case, you are not starting from scratch; ask us and we will tell you what the conversion involves.
One theory, two practicals
The theory exam is shared by both scenarios; what changes is the practical training for each. The course covers the theory and the flight practice at our aerodrome.
What falls on the operator and the drone
The pilot is half of it. The other half belongs to whoever operates, which may be the pilot as a freelancer or the company they fly for.
The operator has to be registered as a UAS operator with AESA and is the one who submits the declaration for the scenario it will use. The declaration is per scenario: declaring STS-01 does not cover STS-02 operations.
And the drone has to carry the class marking each scenario requires. Classes C5 and C6 are defined in Delegated Regulation (EU) 2019/945, and their requirements include direct remote identification. This is what surprises people who come from the open category with their own equipment: not any professional drone will do, only one with that label. Before deciding on a scenario, check what equipment you have, or what the company you want to join uses.
How to choose without overpaying
With all of the above, the choice comes down to three questions about the work you want to do, not about the course.
Will you fly in town or near people? Then you need STS-01. It is the scenario for urban work, construction and a good share of audiovisual work.
Is your work measured in kilometres? Lines, canals, farms, linear works. Then STS-02, because without flying beyond sight those jobs do not pay.
Both? That is common among inspection companies and operators who do not want to turn work down. Since the theory is shared, getting both mostly costs the practical training for the second scenario.
And there is a fourth possible answer: neither. If your operation goes beyond 2 km or 120 metres, flies over uninvolved people or uses a drone over 25 kg, no standard scenario covers it and you need an operational authorisation.
How we train for it at UMILES University
The STS certificate course prepares both scenarios together and includes the open category training. It combines online theory, an in-person session with a specialist before the practical exam and a flight day at our private aerodrome in Madrid, with all the equipment provided.
If you are still not sure whether STS is your next step or another specialisation suits you better, which drone course you need for the job you want compares them all.
Tell us what you will fly and we will tell you which scenario fits
- ✓Training approved by AESA
- ✓Real flight practice, not just theory
- ✓In-person classes in Madrid
- ✓We tell you which route fits you, no strings attached
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