# NTSB investigations: Allison 250 series: Airframe/component/system failure/malfunction

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 CHI07LA277](https://openairdocs.org/ntsb/CHI07LA277.md): Bell 47G-5A · Anoka, MN · Accident · Minor injuries · Limited investigation · Final report · Aug 24, 2007 · N25LB · Substantial damage
  > The loss of helicopter pitch control for undetermined reasons during the aerial application maneuver and the pilot's inability to control the aircraft during the descent.. A contributing factor to the accident was the soft terrain.
- [NTSB SEA94LA149](https://openairdocs.org/ntsb/SEA94LA149.md): Hiller-Soloy UH-12L4 · Clarkston, WA · Accident · Minor injuries · Limited investigation · Final report · Jun 14, 1994 · N67264 · Substantial damage
  > Disconnection of the ballast bar aft retaining pin. Factor(s) were: tail rotor blade separation and reduced aircraft control.
- [NTSB LAX94LA054](https://openairdocs.org/ntsb/LAX94LA054.md): Hiller UH-12E · Salinas, CA · Accident · Minor injuries · Limited investigation · Final report · Nov 20, 1993 · N161HA · Substantial damage
  > a fatigue failure of the torsion-tension bar pin due to fretting corrosion. A factor in this accident was an inadequate quality of material utilized in the manufacture of the pin.
- [NTSB SEA94LA029](https://openairdocs.org/ntsb/SEA94LA029.md): Bell 47G3B2 · Toledo, WA · Accident · No injuries · Limited investigation · Final report · Nov 9, 1993 · N8169J · Substantial damage
  > Transmission shear bolts failed causing a loss of power to the rotor system, and the pilot encountered unsuitable terrain during his autorotation attempt.
- [NTSB MIA92LA014](https://openairdocs.org/ntsb/MIA92LA014.md): Bell 47G-5 · La Belle, FL · Accident · No injuries · Limited investigation · Final report · Oct 13, 1991 · N1201W · Substantial damage
  > The pilot in command's improper aft application of cyclic control during an autorotative landing to an open field, resulting in the main rotor blades colliding with the tail boom. Contributing to the accident was the in flight failure of the outer bearing of…
- [NTSB SEA86FA039](https://openairdocs.org/ntsb/SEA86FA039.md): Hiller-Soloy UH-12E · Horton, OR · Accident · 1 fatal · Field investigation · Final report · Jan 16, 1986 · N40290 · Destroyed
  > The fork connecting the rotorcraft's blue blade to the main rotor hub separated after a long term fatigue crack had spread through more than 60% of the fork circumference. The operator failed to carry out the appropriate inspection of the fork unit as…

## 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."mKey" IN (SELECT x.case_mkey FROM 'https://openairdocs.org/data/latest/ntsb_aircrafts.parquet' x WHERE x.engine_model_code IN ('03014', '03019')
    AND EXISTS (SELECT 1 FROM 'https://openairdocs.org/data/latest/ntsb_occurrences.parquet' o WHERE o.case_mkey = x.case_mkey AND o.aircrafts_position = x.position AND o."occurrenceNumber" = 1 AND o."occurrenceCode" = 130))
ORDER BY c."eventDate" DESC, c."ntsbNumber" DESC
```

This list as a web page: https://openairdocs.org/ntsb?engine=03014&occurrence=130

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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.