First official document of an accident investigation, setting out the facts established in the opening weeks without drawing conclusions about causes.
What it is
ICAO Annex 13 requires the State conducting the investigation to send it within 30 days of the accident to the other States involved and, when the aircraft’s maximum mass exceeds 2,250 kg, to ICAO itself. Many authorities also publish it within that period or shortly afterwards.
Its content is strictly factual: details of the aircraft and crew, the weather, a timeline of the flight, initial data from the recorders, the state of the wreckage and the lines of enquiry still open. It names no causes and no one responsible, and it warns that the information may change as the analysis progresses.
Although it is not conclusive, it serves an immediate safety purpose. If a risk that could affect other aircraft emerges in those first weeks, the authority does not wait for the final report but issues urgent recommendations, which can lead to inspections or procedural changes across the affected fleet. Finding a part with unusual wear, for instance, can trigger checks of that component on other aircraft of the same type within days.
Related terms
Cite
To cite this page in academic work, an article or Wikipedia, choose the style and copy the reference. The access date is today.
This page was last updated on October 9, 2026
APA
Vuelopedia. (2026, October 9). Preliminary report. Retrieved October 19, 2026, from https://vuelopedia.org/en/glossary/preliminary-report
MLA
“Preliminary report.” Vuelopedia, Fundación Poderia, 9 Oct. 2026, vuelopedia.org/en/glossary/preliminary-report. Accessed 19 Oct. 2026.
Chicago
Vuelopedia. “Preliminary report.” Fundación Poderia. Last modified October 9, 2026. https://vuelopedia.org/en/glossary/preliminary-report.
Harvard
Vuelopedia (2026) Preliminary report. Available at: https://vuelopedia.org/en/glossary/preliminary-report (Accessed: 19 October 2026).
BibTeX
@misc{vuelopedia_en_glossary_preliminary_report,
author = {{Vuelopedia}},
title = {{Preliminary report}},
publisher = {Fundación Poderia},
year = {2026},
date = {2026-10-09},
url = {https://vuelopedia.org/en/glossary/preliminary-report},
howpublished = {\url{https://vuelopedia.org/en/glossary/preliminary-report}},
urldate = {2026-10-19},
note = {Accessed 2026-10-19}
}Wikipedia
{{cite web |url=https://vuelopedia.org/en/glossary/preliminary-report |title=Preliminary report |website=Vuelopedia |publisher=Fundación Poderia |date=2026-10-09 |access-date=2026-10-19 |language=en}}