ISO 25013: The Coming Standard for Hydrogen Cylinders on Fuel-Cell Drones — What UAS Programmes Need to Know
ISO/DIS 25013 is the first international standard written specifically for the hydrogen cylinders that fly on fuel-cell drones. Its full title is “Unmanned aircraft systems — General requirements and test methods for the attachable hydrogen cylinders of gaseous hydrogen fuel cell powered UAS,” and it is being developed by ISO/TC 20/SC 16, the committee for uncrewed aircraft systems and advanced air mobility. As of July 2026 it is a Draft International Standard: the DIS public-enquiry window closed on 18 June 2026 and national-body comments are now being processed. Nobody can be certified to it yet — but every serious hydrogen-UAS programme should already be designing with it in view. Here is what is public, what it changes, and what to do about it today.
Why fuel-cell UAS needed their own cylinder standard
Until now, a hydrogen tank on a drone has lived in a regulatory gap. The established composite-cylinder standards were written for other worlds:
- Transportable-cylinder standards — ISO 11119-3, EN 12245 — govern cylinders that are filled, moved and used as general gas packages. They are the workhorse certification route for UAV tanks today, but they were not written with airborne operation, flight loads or quick-swap refuelling in mind.
- Road-vehicle fuel-container standards — UN Regulation 134, ISO 19881 — assume a tank permanently mounted in a car or truck, with crash cases and fire scenarios that don’t map onto a 25-kg airframe. (If you’re navigating that family, start with our guide to what replaced the repealed EC 79.)
- Hydrogen transport standards — EN 17339 — govern the bundles and trailers that move hydrogen to your operation, not the tank on the aircraft. We’ve written a full breakdown of EN 17339.
A flight-weight hydrogen cylinder is a different engineering object from all three: it is weight-critical to the gram, it is handled far more often than a vehicle tank (swapped, recharged, transported between sites), and its failure modes matter in the air and on the ground. ISO/DIS 25013 exists because the fuel-cell-UAS industry grew big enough that “certify it as a generic transportable cylinder and hope the aviation authority accepts it” stopped being good enough.
What the public scope tells us
The draft’s published scope is short but revealing. It specifies the minimum safety, performance and integrity requirements — and the test methods to verify them — for the attachable hydrogen cylinders of gaseous-hydrogen fuel-cell powered UAS.
Two words in that scope deserve attention:
- “Attachable.” The standard is aimed at cylinders designed to be mounted to and removed from the aircraft — the swap-tank operating model, where an empty cylinder comes off and a full one goes on between sorties. That is how real fleets actually achieve availability (see our note on refuelling a drone in 90 seconds), and it is exactly the handling profile that generic cylinder standards never contemplated: repeated mounting cycles, connector wear, field handling by operators rather than gas professionals.
- “Gaseous hydrogen.” Compressed GH₂ only — liquid-hydrogen concepts are a different problem and a different (future) document.
The full technical content of the draft — design margins, test matrix, cycle counts — is available only to national mirror-committee participants and is still subject to change through comment resolution, so we won’t speculate on clause-level detail here. What is certain is the intent: a dedicated qualification path for flight-weight, operator-handled, swappable hydrogen cylinders.
Where ISO 25013 sits in the standards map
| Standard | Governs | Status |
|---|---|---|
| ISO 11119-3 / EN 12245 | Transportable composite cylinders (today’s certification route for UAV hydrogen tanks) | Published, in force |
| EN 17339 | Composite cylinders and tubes for hydrogen transport (bundles, MEGCs, trailers) | Published, 2024 revision |
| UN R134 / ISO 19881 | Hydrogen fuel containers permanently mounted in road vehicles | Published, in force |
| ISO/DIS 25013 | Attachable hydrogen cylinders on fuel-cell UAS | Draft — DIS enquiry closed June 2026 |
| ISO/DIS 25009 | Hydrogen fuel gas pipes for fuel-cell UAS (companion draft) | Draft, same committee |
The committee behind it matters too. ISO/TC 20/SC 16 is an aviation committee — the body that standardises UAS design, operations and traffic management — not a gas-cylinder committee. The cylinder is being treated as an aircraft component, with a companion draft (ISO/DIS 25009) covering the hydrogen fuel lines that connect it to the stack. That framing is the whole point: the fuel system of a hydrogen drone is becoming certifiable equipment, not an adapted gas bottle.
Timeline: what happens next
- 18 June 2026 — DIS public-enquiry window closed; national bodies submitted votes and technical comments.
- Now — comment resolution within ISO/TC 20/SC 16. Depending on the outcome, the project proceeds to a Final Draft (FDIS) ballot or directly to publication.
- Realistically 2027 — publication as ISO 25013, if comment resolution stays on a normal track. Draft content can still change until then.
We will update this article as the project moves stages.
What a UAS programme should do today
- Buy certified against the standards that exist now. Until ISO 25013 publishes, the defensible route for a flight hydrogen cylinder is a certificate against the transportable-cylinder framework — EN 12245 / ISO 11119-3 — plus CE marking where applicable. That is a document set your aviation authority, insurer and safety officer can act on today.
- Treat “ISO 25013 certified” claims as a red flag. Nobody can be certified to a draft. A supplier who claims it either doesn’t understand the process or hopes you don’t. The honest formulation — the one we use ourselves — is designed with the draft’s intent in view, certified to the published standards.
- Design for swappability now. The draft’s focus on attachable cylinders confirms where operations are heading. Standardised mounting interfaces, quick-connect necks and swap-based refuelling are the assumptions to build into your airframe today so that an ISO 25013-qualified cylinder drops in later without a redesign.
- Follow the draft through your national body. If hydrogen UAS is core to your roadmap, your national ISO member body’s mirror committee for TC 20/SC 16 is where you can read the full draft and influence the final text.
Where MEYER stands
We build exactly the object this standard describes: flight-weight, attachable hydrogen cylinders for fuel-cell UAS. Our HDRX-068-H2 (6.8 L / 350 bar, ≈160 g H₂ at 2.8 kg) carries an issued certificate to EN ISO 12245:2022 and CE marking — the published-standards route described above — and is available for pre-order now, with the ultra-light UL variant in qualification behind it. We have contributed to composite-cylinder standardisation before, as working-group participants in CEN/TC 23/WG 16 (the group behind EN 17339), and we are tracking ISO/DIS 25013 through the same lens: when the standard publishes, our hydrogen range will be qualified against it as early as the process allows.
Specifying a hydrogen tank for a UAV right now? Start with our engineering guide, compare the full COPV range, or go straight to the HDRX-068-H2 product page for the datasheet and 3D model.
Sources
- ISO/DIS 25013 — iso.org project page
- ISO/TC 20/SC 16 — Uncrewed aircraft systems
- SFS public-enquiry record (deadline 18 June 2026)
Status current as of 14 July 2026. This article describes a draft standard; technical content may change before publication.
HDRX-068-H2 — 6.8 L / 350 bar hydrogen cylinder for fuel-cell UAS, ≈160 g H₂ at 2.8 kg. Certificate issued to EN ISO 12245:2022, CE marked; batch 1 ships mid-September. Specs, datasheet & 3D model →
Its ultra-light sibling HDRX-068-H2-UL (2.3 kg, same envelope) is in qualification. And to hold ourselves to this article’s own rule: no product can claim ISO 25013 yet — including ours.
