# NTSB investigations: Franklin 6V4 series, IA

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 CHI99LA012](https://openairdocs.org/ntsb/CHI99LA012.md): Hiller UH-12C · Clinton, IA · Accident · No injuries · Limited investigation · Final report · Oct 24, 1998 · N9739C · Substantial damage
  > the failure of the 90 degree gearbox for reasons undetermined. Factors were the failure of the gearbox, and it not being possible for the pilot to maintain control of the aircraft.
- [NTSB MKC67A0034](https://openairdocs.org/ntsb/MKC67A0034.md): Bell 47G · Hariton, IA · Accident · No injuries · Closed · Nov 7, 1966 · N4734S · Substantial damage

## 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 x.case_mkey FROM 'https://openairdocs.org/data/latest/ntsb_aircrafts.parquet' x WHERE x.engine_model_code IN ('27033'))
ORDER BY c."eventDate" DESC, c."ntsbNumber" DESC
```

This list as a web page: https://openairdocs.org/ntsb?engine=27033&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.