There is no fixed timeline — the NTSB itself publishes a general target of completing most investigations within about 12 months, but straightforward general aviation events can close faster, sometimes in a few months, while complex investigations involving fatalities, mechanical failure analysis, or multiple contributing factors can run two years or longer.
What determines the timeline
- Severity and complexity — a minor incident with an obvious, undisputed cause closes far faster than a fatal accident requiring wreckage examination, component testing, or coordination with the aircraft or engine manufacturer.
- Data recovery — if the aircraft carried any recording equipment, or if data has to be pulled from avionics, that process itself takes time before analysis can even begin.
- Docket and hearing requirements — higher-profile investigations may include a public docket release and, rarely, a public hearing, both of which add months.
What a record shows while an investigation is still open
An event appears in NTSB's database as soon as it is reported, well before the investigation concludes — typically first as a preliminary report, with a probable cause determination added once the investigation closes. A records search on an aircraft mid-investigation will show that an event occurred and give you the available preliminary facts, even though the final determination of cause is not yet published. That is worth knowing: an "open" investigation is not a hidden one, and treating it as if nothing has happened yet is the wrong read. Read what has been published, and check back for the final report before treating the case as fully resolved.