# NTSB investigations, IA: Unknown or undetermined

NTSB aviation accident and incident investigations since 1962: the probable cause, findings, aircraft, crew, weather and docket of each, linked to the FAA registry and the FAA’s own reports.

## Latest cases

- [NTSB CEN26FA267](https://openairdocs.org/ntsb/CEN26FA267.md): Zenith Zodiak 601 HDS · Sioux City, IA · Accident · 1 fatal · Class 3 · Field · Preliminary report · Jul 24, 2026 · N27601 · Destroyed
  > On July 24, 2026, about 1422 central daylight time, a Zenith Zodiac 601HDS experimental airplane, N27601, was destroyed when it was involved in an accident near Sioux City, Iowa. The pilot was fatally injured. The airplane was operated as a Title 14 Code of…
- [NTSB ANC25FA086](https://openairdocs.org/ntsb/ANC25FA086.md): North American T-28B · Monticello, IA · Accident · 1 fatal · Class 3 · Field · Preliminary report · Aug 11, 2025 · N28XT · Substantial damage
  > On August 11, 2025, about 1505 Central daylight time, a North American T-28B airplane, N28XT, was substantially damaged when it was involved in an accident near Monticello, Iowa. The pilot was fatally injured. The airplane was operated as a Title 14 Code of…
- [NTSB CEN24LA303](https://openairdocs.org/ntsb/CEN24LA303.md): Robinson Helicopter R44 · Bryant, IA · Accident · No injuries · Class 3 · Limited · Final report · Aug 3, 2024 · N225ML · Substantial damage
  > A loss of engine power during takeoff for reasons that could not be determined, resulting in impact with terrain.
- [NTSB CEN23LA076](https://openairdocs.org/ntsb/CEN23LA076.md): Cessna 182M · Council Bluffs, IA · Accident · No injuries · Class 3 · Limited · Final report · Jan 5, 2023 · N71494 · Substantial damage
  > The partial loss of engine power for reasons that could not be determined.
- [NTSB CEN22LA354](https://openairdocs.org/ntsb/CEN22LA354.md): Air Tractor AT-301 · Lamoni, IA · Accident · No injuries · Class 3 · Limited · Final report · Aug 1, 2022 · N4326S · Destroyed
  > A loss of airplane performance for reasons that could not be determined.
- [NTSB CEN21LA257](https://openairdocs.org/ntsb/CEN21LA257.md): Quad City Challenger · Wallingford, IA · Accident · No injuries · Class 3 · Limited · Final report · Jun 2, 2021 · N3281P · Substantial damage
  > Impact with trees and terrain during takeoff for reasons that could not be determined based on the available information.
- [NTSB CEN13LA287](https://openairdocs.org/ntsb/CEN13LA287.md): Piper PA-28-161 · Oskaloosa, IA · Accident · Minor injuries · Limited investigation · Final report · May 18, 2013 · N47539 · Substantial damage
  > The loss of engine power for reasons that could not be determined because the engine examination did not reveal any malfunctions or failures that would have precluded normal operation.

## The whole list in SQL

Runs in DuckDB 1.2 or later on the release's Parquet files over HTTPS:

```sql
SELECT c."ntsbNumber", c."eventDate", c."eventType", c."eventCity", c."eventStateOrRegion", a.n_number, a."aircraftMake", a."aircraftModel", c."highestInjuryLevel", c."totalFatal", c."completionStatus", c.report_url
FROM 'https://openairdocs.org/data/latest/ntsb_case_detail.parquet' c LEFT JOIN 'https://openairdocs.org/data/latest/ntsb_aircrafts.parquet' a ON a.case_mkey = c."mKey" AND a.position = 1
WHERE c."eventStateOrRegion" = 'IA' AND c."eventCountry" = 'USA'
  AND c."mKey" IN (SELECT s.case_mkey FROM 'https://openairdocs.org/data/latest/ntsb_events.parquet' s WHERE s."tier2Number" = '000' AND s.case_mkey IN (SELECT case_mkey FROM 'https://openairdocs.org/data/latest/ntsb_events.parquet' WHERE "isDefiningEvent"))
ORDER BY c."eventDate" DESC, c."ntsbNumber" DESC
```

This list as a web page: https://openairdocs.org/ntsb-events/000/sequence?state=IA

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OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.