Terms of reuse for the material published here, and the basis for it.
Summary. The editorial content of this site — summaries, event chains, analysis, taxonomy, translations — is published under CC BY-SA 4.0. The underlying facts are not subject to copyright. The official investigation reports are not redistributed here; they are linked at source and remain under each authority's terms. This site is operated non-commercially.
Three layers, three different rights positions.
| Layer | Content | Rights |
|---|---|---|
| Source documents | The official PDF investigation reports of the six safety authorities. | The authorities'. Not redistributed here — see §4. |
| Facts | Date, place, aircraft type, flight phase, injuries, sequence of events, the authority's stated conclusion. | Not subject to copyright in any jurisdiction involved. |
| Editorial layer | Every title, summary, event chain, analysis, safety tag and translation on this site, written from the source reports in four languages. | Original work of the operator. Licensed below. |
No editorial text on this site reproduces an authority's text. Each record is written from the source report and checked against it. Quoted material is marked and attributed — see §3.
Not every published investigation report becomes a record here. A report is included only if the issuing authority documents investigative work of its own — a site visit, an examination of the aircraft or a component, witness statements, recorded flight or radar data, maintenance or licensing records checked, or an attempted determination whose outcome the authority reports, including where it reports that a point could not be established.
A report whose entire factual basis is the account of the crew involved is not included. Some authorities publish such reports and say so plainly: two Swiss summary reports in this category state “Es wurde keine Untersuchung durchgeführt. Der Bericht basiert auf den verfügbaren Aussagen.” — no investigation was carried out, the report rests on the available statements. A US short-form disposition may record only that the authority did not travel to the scene, with a public docket containing nothing but the pilot’s own accident form.
This standard is applied to every authority on the same terms, and it is applied to the document, not to the authority’s reputation. It was introduced in September 2026 and applied retrospectively: 57 previously published records were withdrawn, 46 of them from one authority and 11 from two others. Withdrawn records are retained unpublished and can be restored if better evidence of the underlying investigation emerges.
Two consequences a reader should weigh. The dataset now under-represents minor occurrences, because authorities investigate least where nobody was hurt — the withdrawn records contained no fatalities and were mostly injury-free. And the standard measures what an authority documents, which is not always what it did: a short report can follow a real enquiry, and five records were retained on exactly that ground after re-reading.
The editorial layer is licensed under Creative Commons Attribution-ShareAlike 4.0 International. It may be copied, redistributed, adapted and built upon, including commercially, subject to two conditions:
Where a sui generis database right under Directive 96/9/EC subsists in this database, it is granted on the same terms.
Single record:
gliderincidents.com, record <id>, CC BY-SA 4.0.
Source report: <authority>, <reference>.
Dataset:
Glider Incidents (gliderincidents.com), CC BY-SA 4.0. Derived from official investigation reports of the BFU, SUST, BEA, SUB, NTSB and AAIB.
These terms apply to use in training or grounding a machine-learning system. A general acknowledgement of “public web data” does not satisfy the attribution condition. Each record carries its originating authority and that authority's reference number.
The dataset is served by an open, read-only MCP endpoint; these terms apply to what it returns. Endpoint, tools and limits are documented on the data access page.
| Authority | Country | Stated position on reuse |
|---|---|---|
| BFU | Germany | Website terms permit personal and journalistic use with the attribution © Copyright Bundesstelle für Flugunfalluntersuchung (BFU); other uses by prior written consent. Use here is non-commercial and attributed. See §6. |
| SUST | Switzerland | Reports of authorities are excluded from copyright protection by Art. 5 para. 1 lit. c URG. |
| BEA | France | Non-commercial reuse permitted, conditional on preserving the integrity of the information and stating its origin and publication date. Use here meets those conditions as written. |
| SUB | Austria | No separately published reuse terms located. Austrian §7 UrhG exempts official works; §6 applies by analogy. |
| NTSB | United States | Public domain under 17 U.S.C. §105. The NTSB asks that use be accurate and complete; credit as “Courtesy: National Transportation Safety Board”. |
| AAIB | United Kingdom | Crown copyright, published on GOV.UK under the Open Government Licence v3.0, permitting commercial reuse with attribution. |
Every record names its originating authority and that authority's reference number, and links to the source document.
The BFU is the largest single source in this corpus and its published website terms are the most restrictive of the six. The position taken here is stated in full.
Primary. BFU documents are not redistributed, BFU report text is not published, and BFU images are not reproduced. What is published about a BFU-investigated accident is (a) facts, which are not subject to copyright, and (b) original German, English, French and Spanish prose written for this site. Neither requires a licence. The use is additionally non-commercial, which places it within the BFU's published terms without reaching the statutory question.
Secondary, as to the reports. A published BFU investigation report is considered here to be an amtliches Werk within the meaning of §5(2) UrhG — an official work published in the official interest for general public awareness — and therefore free of copyright protection, subject to the conditions on alteration and source attribution in §62 and §63 UrhG, which are observed. The report is published by statutory obligation under Regulation (EU) No 996/2010 Art. 16 and the German FlUUG, for the purpose of dissemination in the interest of flight safety.
The BFU's own website notice asserts a broader copyright. That notice is not treated here as determining the statutory question. §5(2) as applied to investigation reports is not settled by case law. This is a legal opinion and is identified as such.
In either case: the BFU is attributed on every record derived from its work, its documents are neither altered nor redistributed, and the original is linked.
Die BFU ist die größte Einzelquelle dieses Bestandes. Die hier vertretene Position wird vollständig dargelegt.
Primär. BFU-Dokumente werden nicht weiterverbreitet, BFU-Berichtstext wird nicht veröffentlicht, Abbildungen der BFU werden nicht wiedergegeben. Veröffentlicht werden ausschließlich (a) Tatsachen, an denen kein Urheberrecht besteht, und (b) eigenständig für diese Seite verfasste deutsche, englische, französische und spanische Texte. Beides bedarf keiner Lizenz. Die Nutzung erfolgt zudem nicht kommerziell und bewegt sich damit innerhalb der veröffentlichten Nutzungsbedingungen der BFU, ohne dass es auf die gesetzliche Frage ankommt.
Sekundär, zu den Berichten. Ein veröffentlichter BFU-Untersuchungsbericht wird hier als amtliches Werk im Sinne des § 5 Abs. 2 UrhG angesehen, das im amtlichen Interesse zur allgemeinen Kenntnisnahme veröffentlicht wurde und damit keinen Urheberrechtsschutz genießt — vorbehaltlich des Änderungsverbots und der Pflicht zur Quellenangabe nach §§ 62, 63 UrhG, die beachtet werden. Der Bericht wird kraft gesetzlicher Verpflichtung nach Art. 16 der Verordnung (EU) Nr. 996/2010 sowie nach dem FlUUG veröffentlicht, zum Zweck der Verbreitung im Interesse der Flugsicherheit.
Der Impressumshinweis der BFU behauptet einen weitergehenden Urheberrechtsschutz. Er wird hier nicht als Entscheidung der gesetzlichen Frage behandelt. § 5 Abs. 2 UrhG ist in Bezug auf Untersuchungsberichte höchstrichterlich nicht geklärt. Es handelt sich um eine Rechtsauffassung und wird als solche bezeichnet.
In beiden Fällen gilt: Die BFU wird bei jedem auf ihrer Arbeit beruhenden Datensatz genannt, ihre Dokumente werden weder verändert noch weiterverbreitet, und das Original wird verlinkt. Beanstandungen an tom@segelflug.io.
Copyright protects expression, not information. That an aircraft of a given type landed short at a named airfield on a given date, and that the investigating authority attributed it to a particular cause, are facts. They may be restated freely, and are restated here in original wording. No terms of use render a fact proprietary, and none of the six authorities asserts otherwise. Protection of a factual compilation in the EU arises through the sui generis database right, addressed in §2.
Records concern accidents involving identifiable people. Editorial policy excludes names, genders, specific injuries and other directly identifying detail. Pilot age is banded to five years wherever it is published or served; exact ages are not published in prose. Operational experience figures are carried in the form the authority published them. Requests concerning an identifiable individual: tom@segelflug.io. See also the privacy policy.
Records are written from source documents by a human editor and may contain errors. Reports of a record misstating an authority's findings are welcome, via the flag control on each record or tom@segelflug.io. This applies equally to the authorities named above.