# NTSB investigations: Allison 250-C20 series, CO

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 CEN20LA273](https://openairdocs.org/ntsb/CEN20LA273.md): Aerospatiale AS355 · Rifle, CO · Accident · Serious injuries · Class 3 · Limited · Final report · Jul 11, 2020 · N708AC · Destroyed
  > A loss of tail rotor effectiveness, the pilot’s subsequent loss of helicopter control, and collision with terrain.
- [NTSB CEN20LA073](https://openairdocs.org/ntsb/CEN20LA073.md): Hiller UH 12E · Dinosaur, CO · Accident · No injuries · Class 3 · Limited · Final report · Feb 1, 2020 · N7173S · Substantial damage
  > Failure of a S4 compressor blade due to a fatigue crack that likely initiated at a corrosion pit. Contributing to the accident was maintenance personnel’s failure to detect the corrosion pits during maintenance.
- [NTSB CEN17LA314](https://openairdocs.org/ntsb/CEN17LA314.md): Hughes 369D · Villa Grove, CO · Accident · Serious injuries · Limited investigation · Final report · Aug 10, 2017 · N58424 · Substantial damage
  > The pilot’s failure to maintain main rotor clearance from a power line tower during low-level maneuvering.
- [NTSB CEN10CA545](https://openairdocs.org/ntsb/CEN10CA545.md): Aerospatiale AS 355F1 · Pikes Peak, CO · Accident · Serious injuries · Data collection · Final report · Sep 17, 2010 · N5802W · Substantial damage
  > The helicopter's encounter with an unexpected downdraft, which resulted in a hard landing.
- [NTSB DEN07LA132](https://openairdocs.org/ntsb/DEN07LA132.md): Bell 206B · Broomfield, CO · Accident · Minor injuries · Limited investigation · Final report · Aug 1, 2007 · N568TD · Substantial damage
  > The pilot's failure to maintain control of the helicopter, resulting in an inadvertent dynamic rollover.
- [NTSB DEN02LA036](https://openairdocs.org/ntsb/DEN02LA036.md): Bell 206B-III · Leadville, CO · Accident · No injuries · Limited investigation · Final report · Apr 4, 2002 · N997GM · Destroyed
  > the pilot's inadvertent flight into adverse weather, which resulted in a collision with terrain. A contributing factor was the downdraft.
- [NTSB FTW95TA228](https://openairdocs.org/ntsb/FTW95TA228.md): Bell 206B-III · Meeker, CO · Accident · No injuries · Final report · Jun 2, 1995 · N85RP · Substantial damage
  > Failure by the pilot to maintain control of the aircraft during landing. A factor was soft terrain.
- [NTSB FTW94T#A01](https://openairdocs.org/ntsb/FTW94T%23A01.md): Bell 206A · Estes Park, CO · Accident · No injuries · Class 3 · Final report · Jun 26, 1994 · N7881S · Substantial damage
- [NTSB DEN89LA090](https://openairdocs.org/ntsb/DEN89LA090.md): Bell 222 · Leadville, CO · Accident · No injuries · Limited investigation · Final report · Mar 23, 1989 · N5008Q · Substantial damage
  > Failure of the pilot to compensate adequately for wind conditions with rudder pedals while maneuvering in unfavorable wind and high density altitude.

## 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" = 'CO' 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 ('03020'))
ORDER BY c."eventDate" DESC, c."ntsbNumber" DESC
```

This list as a web page: https://openairdocs.org/ntsb?engine=03020&state=CO

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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.