# NTSB investigations: Allison 250 SER 400HP, 1991

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 FTW91LA121](https://openairdocs.org/ntsb/FTW91LA121.md): Bell 206B · Freeport, TX · Accident · No injuries · Limited investigation · Final report · Jul 14, 1991 · N16962 · Substantial damage
  > The pilot's failure to maintain sufficient rotor RPM during the autorotation. Factors were the fuel exhaustion induced power loss due to the pilot's improper pre-flight inspection.
- [NTSB LAX91LA205](https://openairdocs.org/ntsb/LAX91LA205.md): Bell 206 · Searchlight, NV · Accident · Minor injuries · Limited investigation · Final report · May 6, 1991 · N49720 · Destroyed
  > Cannot be determined in that the helicopter was stolen and the certainty of the resulting damage to the helicopter may have been intentional or accidental.
- [NTSB LAX91LA198](https://openairdocs.org/ntsb/LAX91LA198.md): Hughes 369HS · Keanae, HI · Accident · Minor injuries · Limited investigation · Final report · May 5, 1991 · N9219F · Substantial damage
  > The total failure in fatigue of the helicopter's spur adapter gearshaft. A contributing factor was related to the lack of a suitable emergency landing site.
- [NTSB LAX91LA172](https://openairdocs.org/ntsb/LAX91LA172.md): Hughes 369C · Papua, Papua New Guinea · Accident · Minor injuries · Limited investigation · Final report · Apr 2, 1991 · N9227F · Destroyed
  > The loss of control of the helicopter due to a restriction of the cyclic control system.
- [NTSB BFO91LA036](https://openairdocs.org/ntsb/BFO91LA036.md): Hughes 369HS · Columbia, MD · Accident · No injuries · Limited investigation · Final report · Mar 27, 1991 · N5FC · Substantial damage
  > The pilot's inadequate visual lookout, which resulted in his failure to see-and-avoid the obstruction (fence post).

## 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 year(c."eventDate") = 1991
  AND c."mKey" IN (SELECT x.case_mkey FROM 'https://openairdocs.org/data/latest/ntsb_aircrafts.parquet' x WHERE x.engine_model_code IN ('03013', '03012'))
ORDER BY c."eventDate" DESC, c."ntsbNumber" DESC
```

This list as a web page: https://openairdocs.org/ntsb?engine=03013&year=1991

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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.