# NTSB investigations: Franklin 6V4 series, IL

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 CHI84LA181](https://openairdocs.org/ntsb/CHI84LA181.md): Bell 47D-1 · Ridge Farm, IL · Accident · No injuries · Limited investigation · Final report · May 6, 1984 · N13012 · Substantial damage
  > The helicopter rolled over after a hard landing following loss of rotor RPM. The plt reported that during initial climb at about 300 ft AGL the rotor decreased about 500 RPM. He tried to regain rotor RPM until about 100 ft AGL and then tried an autorotation.…
- [NTSB CHI80DEV30](https://openairdocs.org/ntsb/CHI80DEV30.md): Bell 47D-1 · Rantoul, IL · Accident · No injuries · Closed · Jul 28, 1980 · N8271E · Substantial damage
- [NTSB CHI75DEV36](https://openairdocs.org/ntsb/CHI75DEV36.md): Bell 47D-1 · Carmi, IL · Accident · No injuries · Closed · Jun 6, 1975 · N74121 · Destroyed
- [NTSB CHI74FEV49](https://openairdocs.org/ntsb/CHI74FEV49.md): Hiller Acft UH-12A · Springfield, IL · Accident · No injuries · Closed · May 1, 1974 · N7636B · Substantial damage
- [NTSB UNK64X1983](https://openairdocs.org/ntsb/UNK64X1983.md): Bell 47G · Pana, IL · Accident · No injuries · Closed · May 27, 1964 · 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" = 'IL' 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=IL

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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.