# NTSB investigations: Pratt & Whitney PT6A series, MT

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 WPR25LA122](https://openairdocs.org/ntsb/WPR25LA122.md): Beech C90A · Helena, MT · Accident · No injuries · Class 3 · Limited · Final report · Mar 16, 2025 · N513JM · Substantial damage
  > The failure of the left main landing gear to fully extend and lock as a result of broken downlock switch wires and the failure of the pilots to complete the manual gear extension checklist.
- [NTSB WPR21LA313](https://openairdocs.org/ntsb/WPR21LA313.md): Cessna 425 · Helena, MT · Accident · Serious injuries · Class 3 · Limited · Final report · Aug 11, 2021 · N783MB · Substantial damage
  > A flameout of both engines due to fuel starvation for reasons that could not be determined due to the airplane’s damage.
- [NTSB WPR20LA128](https://openairdocs.org/ntsb/WPR20LA128.md): Piper PA31T · Billings, MT · Accident · 1 fatal · Class 3 · Limited · Final report · Apr 20, 2020 · N926K · Destroyed
  > The degraded airplane performance after takeoff for reasons that could not be determined from available evidence.
- [NTSB WPR17LA056](https://openairdocs.org/ntsb/WPR17LA056.md): Beech 99 · Billings, MT · Accident · No injuries · Limited investigation · Final report · Jan 19, 2017 · N326CA · Substantial damage
  > The fatigue failure of the left main landing gear (MLG) actuator piston rod, which prevented the hydraulic system from producing pressure to control the MLG’s position and led to the right MLG collapsing during landing.
- [NTSB WPR17LA031](https://openairdocs.org/ntsb/WPR17LA031.md): Piper PA 31T · Missoula, MT · Accident · No injuries · Limited investigation · Final report · Dec 5, 2016 · N909PW · Substantial damage
  > Failure of the left windshield due to moisture ingression into the windshield laminate, which deteriorated the strength of the windshield.
- [NTSB WPR11FA221](https://openairdocs.org/ntsb/WPR11FA221.md): Air Tractor AT-802A · Miles City, MT · Accident · 1 fatal · Field investigation · Final report · May 9, 2011 · N8523H · Substantial damage
  > The pilot's continued visual flight rules flight into deteriorating weather conditions in an airplane not equipped for instrument flight, which resulted in a collision with terrain.
- [NTSB SEA07LA133](https://openairdocs.org/ntsb/SEA07LA133.md): Beech B-99 · Billings, MT · Accident · No injuries · Limited investigation · Final report · May 19, 2007 · N950AA · Substantial damage
  > The total failure of the nose landing gear actuator and the subsequent nose gear collapse during landing.
- [NTSB SEA05LA010](https://openairdocs.org/ntsb/SEA05LA010.md): Beech 99A · Billings, MT · Accident · No injuries · Limited investigation · Final report · Oct 18, 2004 · N955AA · Substantial damage
  > the pilot's failure to follow the instrument approach procedure, which resulted in a premature descent below the decision height and subsequent collision with a building.
- [NTSB SEA01LA139](https://openairdocs.org/ntsb/SEA01LA139.md): Pilatus PC-6/B2-H4 · Great Falls, MT · Accident · No injuries · Limited investigation · Final report · Jul 21, 2001 · N2TS · Substantial damage
  > Pilot's failure to maintain directional control of the aircraft while landing.

## 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" = 'MT' 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 ('52032', '52034'))
ORDER BY c."eventDate" DESC, c."ntsbNumber" DESC
```

This list as a web page: https://openairdocs.org/ntsb?engine=52032&state=MT

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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.