# NTSB investigations: Allison 250 series, WA

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 WPR27LA011](https://openairdocs.org/ntsb/WPR27LA011.md): Enstrom Helicopter 480 · Chelan, WA · Accident · No injuries · Class 4 · Limited · Investigation open · Sep 30, 2026 · N480MT
- [NTSB WPR09CA331](https://openairdocs.org/ntsb/WPR09CA331.md): Bell 47G-3B-2 · Ocean Shores, WA · Accident · Minor injuries · Data collection · Final report · Jul 7, 2009 · N8169J · Substantial damage
  > The pilot's failure to maintain clearance from the water while maneuvering due to the pilot's diverted attention.
- [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 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 SEA90LA025](https://openairdocs.org/ntsb/SEA90LA025.md): Hiller UH-12E · Raymond, WA · Accident · No injuries · Limited investigation · Final report · Nov 29, 1989 · N9762C · Substantial damage
  > Loss of engine power due to fatigue failure of the impeller. The helicopter was substantially damaged as a result of a roll-over on uneven terrain.
- [NTSB SEA82DA164](https://openairdocs.org/ntsb/SEA82DA164.md): Hiller-Soloy UH-12E · Spirit Lake, WA · Accident · No injuries · Final report · Sep 15, 1982 · N513HA · Substantial damage
  > Pilot performed autorotation from 2000 feet to check RPM. At 200-300 feet when collective was added power loss occurred. Aircraft landed hard and severed tail boom. Logging support operations.
- [NTSB SEA81DYE08](https://openairdocs.org/ntsb/SEA81DYE08.md): Hiller Acft UH-12E · Forks, WA · Accident · No injuries · Closed · Nov 19, 1980 · N542HA · Substantial damage
- [NTSB SEA80DYE32](https://openairdocs.org/ntsb/SEA80DYE32.md): Hiller Acft UH-12E · Forks, WA · Accident · Serious injuries · Closed · May 15, 1980 · N5359V · Destroyed
- [NTSB SEA78FYE16](https://openairdocs.org/ntsb/SEA78FYE16.md): Hiller Acft UH-12E · Forks, WA · Accident · No injuries · Closed · Mar 20, 1978 · N5359V · Substantial damage
- [NTSB SEA76DYE65](https://openairdocs.org/ntsb/SEA76DYE65.md): Hiller Acft UH-12E · Humptulips, WA · Accident · Serious injuries · Closed · Sep 7, 1976 · N48001 · Substantial damage
- [NTSB SEA76DYG44](https://openairdocs.org/ntsb/SEA76DYG44.md): Bell 47G-3B · Palouse, WA · Accident · No injuries · Closed · Apr 21, 1976 · N2240W · Destroyed
- [NTSB SEA74DYG50](https://openairdocs.org/ntsb/SEA74DYG50.md): Bell 47G3B2 · Clarkston, WA · Accident · Minor injuries · Closed · Jun 23, 1974 · N8169J · 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" = 'WA' 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 ('03014', '03019'))
ORDER BY c."eventDate" DESC, c."ntsbNumber" DESC
```

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

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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.