# NTSB investigations: Franklin 6V4 series, OK

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 FTW02LA044](https://openairdocs.org/ntsb/FTW02LA044.md): Bell 47G · Ardmore, OK · Accident · No injuries · Limited investigation · Final report · Dec 1, 2001 · N5226 · Substantial damage
  > the flight instructor's selection of an unsuitable area for practicing a full touchdown autorotation, which resulted in a nose over. A contributing factor was the soft ground.
- [NTSB FTW96LA192](https://openairdocs.org/ntsb/FTW96LA192.md): Bell 47D1 · Ardmore, OK · Accident · No injuries · Limited investigation · Final report · Apr 26, 1996 · N5226 · Substantial damage
  > the student's inadvertent dynamic rollover, and inadequate supervision by the flight instructor.
- [NTSB FTW94LA193](https://openairdocs.org/ntsb/FTW94LA193.md): Bell 47H-1 · Tulsa, OK · Accident · No injuries · Limited investigation · Final report · Jun 4, 1994 · N2831B · Substantial damage
  > The pilot's failure to maintain rotor RPM, his delayed landing flare, and the improper touchdown.
- [NTSB FTW94LA166](https://openairdocs.org/ntsb/FTW94LA166.md): Bell 47G · Sulphur, OK · Accident · No injuries · Limited investigation · Final report · May 18, 1994 · N933B · Substantial damage
  > The loss of engine power due to the failure of an engine accessory oil pump gear. A factor was the lack of suitable terrain for the autorotation.
- [NTSB FTW85LA074](https://openairdocs.org/ntsb/FTW85LA074.md): Bell 47D1 · Ardmore, OK · Accident · Serious injuries · Limited investigation · Final report · Dec 7, 1984 · N5226 · Substantial damage
  > The acft collided with power lines during a recovery from a practice autorotational landing. The instructor plt took control of the acft for recovery and did not see the wires.
- [NTSB FTW80FPM14](https://openairdocs.org/ntsb/FTW80FPM14.md): Bell 47G · Calvin, OK · Accident · 1 fatal · Closed · Jul 16, 1980 · N16657 · Destroyed
- [NTSB FTW77FPM13](https://openairdocs.org/ntsb/FTW77FPM13.md): Bell 47G · Copan, OK · Accident · No injuries · Closed · Jun 15, 1977 · N16657 · Substantial damage
- [NTSB FTW76FPJ19](https://openairdocs.org/ntsb/FTW76FPJ19.md): Hiller Acft UH-12A · Ada, OK · Accident · No injuries · Closed · Dec 13, 1975 · N8117H · Substantial damage
- [NTSB FTW74FPM29](https://openairdocs.org/ntsb/FTW74FPM29.md): EL Tomcat 47 · Zafra, OK · Accident · No injuries · Closed · Jun 19, 1974 · N4227A · Destroyed

## 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" = 'OK' 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=OK

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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.