Running the wrong type of organisation isn't just a paperwork problem. If you're delivering training that requires ATO approval under a DTO declaration, you're operating outside your authorisation — and that puts your students' licences at risk, not just your own.
The distinction between a Declared Training Organisation and an Approved Training Organisation matters most at the point when you're setting up, expanding your course catalogue, or converting an existing flying club into something more structured. Get it right early and you save months of rework.
What the Regulation Actually Says
The DTO framework was introduced by Regulation (EU) 2018/1119, which amended Part-FCL and created a lighter-touch pathway for organisations delivering certain categories of training. Instead of going through a full competent authority approval process, a DTO submits a declaration and a training programme to the relevant National Aviation Authority (NAA). The NAA acknowledges it — they don't approve it in the traditional sense.
That distinction has real consequences. A DTO is not "a small ATO." It's a different legal status with a defined and limited scope.
An ATO, by contrast, holds a certificate issued by the competent authority under Part-ORA (Organisation Requirements for Aircrew). That certificate can authorise a wide range of training, including the courses a DTO cannot touch.
What a DTO Can and Cannot Deliver
This is where most of the confusion sits. A DTO is authorised to provide training for:
- LAPL (Light Aircraft Pilot Licence) — aeroplane, helicopter, sailplane, balloon
- PPL (Private Pilot Licence) — aeroplane, helicopter, sailplane, balloon
- Sailplane and balloon ratings associated with those licences
- Night rating (NR)
- En-route instrument rating (EIR) — aeroplane only
- Basic instrument rating (BIR) — aeroplane only
- Class and type ratings for single-engine non-high-performance aircraft (where the rating requires dual instruction)
- Towing and aerobatic ratings
- Flight instructor ratings — but only FI(A), FI(S), FI(B), FI(H) courses where the underlying licence is within DTO scope
A DTO cannot deliver:
- CPL (Commercial Pilot Licence)
- ATPL (Airline Transport Pilot Licence), integrated or modular
- IR(A) full instrument rating (the traditional Part-FCL IR)
- Multi-engine class ratings (MEP)
- Type ratings for complex or high-performance aircraft
- Multi-crew pilot licence (MPL)
- Any synthetic training device (FSTD) qualification courses that require ATO status
If you plan to run a PPL-only school, a DTO is probably sufficient. If you want to offer CPL modular training, IR, or MEP — you need an ATO, full stop.
The Overhead Difference Is Real, But Don't Romanticise It
The DTO route exists because the European legislature recognised that a small club running PPL courses shouldn't face the same compliance burden as a Part-141 equivalent operation. That's a reasonable policy position.
In practice, a DTO still requires:
- A declared Head of Training (HT) who meets the qualification requirements
- A training programme submitted to and acknowledged by the NAA
- Adequate facilities, aircraft, and instructor qualifications
- A safety management approach (proportionate, but not optional)
- Record-keeping that satisfies Part-FCL requirements
The ATO route adds on top of that:
- A formal quality management system (QMS) with defined procedures, audits, and corrective action processes
- An Accountable Manager who takes formal regulatory responsibility
- Compliance monitoring — either an internal function or a contracted one
- Nominated persons for training, ground school, and (where applicable) synthetic flight instruction
- A full Operations Manual accepted by the NAA
- Ongoing oversight visits from the competent authority, not just an initial acknowledgement
For a startup school with two aircraft and a handful of instructors, that ATO overhead is significant. For an organisation that wants to grow into commercial training, it's unavoidable — and building the systems early is less painful than retrofitting them later.
Choosing Based on Your Course Catalogue
The honest answer to "which do I need" is: start with what you plan to teach in the next three years, not just what you're doing on day one.
A few scenarios that come up regularly:
You're a flying club that wants to formalise PPL training. A DTO is almost certainly the right starting point. The declaration process is lighter, the ongoing compliance burden is proportionate, and you can deliver everything your students need through PPL level including night ratings and the BIR.
You want to add a modular IR(A) course to an existing PPL programme. The full IR(A) is outside DTO scope. You'll need ATO approval for that specific course. Some organisations hold dual status — DTO for their PPL stream, ATO for IR — but check with your NAA on how they handle that administratively, because it varies.
You're starting from scratch and your business plan includes CPL modular training within two years. Go straight for ATO. The DTO declaration won't authorise CPL training, and converting mid-stream means rebuilding your documentation, your QMS, and going back through the authority. That's expensive in time and money.
You're an ultralight or microlight school operating outside EASA aircraft categories. Neither DTO nor ATO may apply — national regulations govern that space. This article covers EASA-regulated aircraft and licences only.
What NAAs Actually Look At
For a DTO declaration, the NAA will check that your training programme covers the required syllabus elements from Part-FCL Appendices, that your Head of Training is qualified, and that your declared facilities and aircraft are appropriate. They're not conducting a deep audit at the outset — that comes later through oversight.
For an ATO application, expect a more thorough pre-approval process. The authority will review your Operations Manual, your QMS documentation, your nominated persons' CVs and qualifications, your training devices (if any), and your facilities. In many member states, this process takes several months. Budget for it.
One thing that catches people out: the NAA that oversees your DTO or ATO is the authority of the member state where your principal place of business is located — not the state where your aircraft are registered, and not the state where your students are from. If you're setting up in Romania, RCAA is your authority. If you're in Germany, LBA or the relevant Landesluftfahrtbehörde. Know who you're dealing with before you start.
Instructor Qualifications Don't Change Based on Your Status
Whether you're a DTO or an ATO, your instructors need to hold the appropriate FI, CRI, IRI, or other rating under Part-FCL. The organisational status doesn't lower the bar on individual qualifications. A DTO doesn't let you use instructors who wouldn't qualify under ATO rules — it just changes the organisational wrapper around them.
The Operational Layer
Once you've resolved your regulatory status, the operational reality is that both DTOs and ATOs deal with the same daily problems: scheduling conflicts, aircraft availability, maintenance squawks, billing disputes, and documentation that needs to be in order when the authority shows up.
Planebooker is built around that operational layer — scheduling with conflict detection, dispatch with weight & balance and live weather, flight record capture, fleet maintenance tracking, and billing. It works for DTOs running a tight PPL programme and for ATOs managing a larger fleet and instructor pool. The scheduling and dispatch tools don't care about your organisational status; they care about whether your aircraft is serviceable and your instructor is available.
If you're running CAMO or CAO functions alongside your training operation, the airworthiness module covers AMP management, ARC tracking, and AD/SB compliance — which matters whether you're a DTO or an ATO.
Before You File Anything
A few questions worth answering before you approach your NAA:
- List every course you intend to deliver in the next 36 months. Check each one against the DTO scope in Part-FCL and Regulation (EU) 2018/1119. If any fall outside, you need ATO approval.
- Identify your Head of Training candidate. Do they meet the qualification requirements? For an ATO, do your other nominated persons meet the Part-ORA requirements?
- Talk to your NAA early — informally if possible. Most authorities have pre-application guidance or will take a preliminary meeting. That conversation is worth more than any checklist.
- If you're an existing club considering formalisation, audit your current records and aircraft documentation first. Gaps that were tolerable informally become problems when an authority is reviewing your declaration or application.
The DTO pathway is genuinely useful for the right school. The ATO pathway is genuinely necessary for others. Neither is universally better — the right answer depends entirely on what you're teaching.