# NTSB investigations, MT: Unknown or undetermined

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 WPR25FA289](https://openairdocs.org/ntsb/WPR25FA289.md): Murphy SR3500 · Bigfork, MT · Accident · 1 fatal · Class 3 · Field · Preliminary report · Sep 19, 2025 · N62ZT · Destroyed
  > On September 19, 2025, about 1205 mountain daylight time, an experimental amateur built Murphy SR3500, N62ZT, was destroyed when it was involved in an accident near Bigfork, Montana. The pilot was fatally injured. The airplane was operated as a Title 14 Code…
- [NTSB WPR24FA132](https://openairdocs.org/ntsb/WPR24FA132.md): Bell 206-L4 · Anaconda, MT · Accident · 1 fatal · Class 3 · Field · Final report · Apr 26, 2024 · N988B · Destroyed
  > A total loss of engine power due to a loss of cooling oil to the turbine-to-compressor coupling shaft and subsequent fracture of the shaft at an altitude too low for the pilot to complete a successful autorotation. Contributing to the accident was carbon…
- [NTSB WPR23FA286](https://openairdocs.org/ntsb/WPR23FA286.md): Risen 915 iS · Glendive, MT · Accident · 1 fatal · Class 3 · Field · Final report · Jul 28, 2023 · N2442 · Destroyed
  > The pilot’s failure to maintain airspeed, which resulted in an exceedance of the airplane’s critical angle of attack and an aerodynamic stall/spin.
- [NTSB WPR23LA269](https://openairdocs.org/ntsb/WPR23LA269.md): CSP Leasing MTO Sport · Gardiner, MT · Accident · Minor injuries · Class 3 · Limited · Final report · Jun 1, 2023 · N207AG · Substantial damage
  > Failure of the rudder/nosewheel steering system for reasons that could not be determined, which resulted in loss of yaw control and a subsequent rollover.
- [NTSB WPR22LA313](https://openairdocs.org/ntsb/WPR22LA313.md): Piper PA-30 · St Ignatius, MT · Accident · Minor injuries · Class 3 · Limited · Final report · Aug 23, 2022 · N4009Y · Substantial damage
  > A partial loss of power during takeoff for undetermined reasons.
- [NTSB WPR21LA032](https://openairdocs.org/ntsb/WPR21LA032.md): Cessna 172 · Billings, MT · Accident · 1 fatal · Class 3 · Limited · Final report · Oct 31, 2020 · N124TW · Substantial damage
  > The pilot’s failure to maintain the proper descent glide path while on final approach for reasons that could not be determined from available evidence.
- [NTSB WPR17LA046](https://openairdocs.org/ntsb/WPR17LA046.md): Softex Invest V-24L · Paradise, MT · Accident · Serious injuries · Limited investigation · Final report · Jan 3, 2017 · N710XP · Substantial damage
  > A partial loss of power during cruise flight for reasons that could not be determined because postaccident examination of the engines did not reveal evidence of any preimpact mechanical malfunctions or failures that would have precluded normal operation.
- [NTSB WPR16FA182](https://openairdocs.org/ntsb/WPR16FA182.md): Beech 95 B55 (T42A) · Broadus, MT · Accident · 3 fatal · Field investigation · Final report · Sep 17, 2016 · N413D · Substantial damage
  > The airplane's departure from cruise flight for reasons that could not be determined based on the available information.
- [NTSB WPR11LA272](https://openairdocs.org/ntsb/WPR11LA272.md): Air Tractor AT-301 · Hogeland, MT · Accident · 1 fatal · Limited investigation · Final report · Jun 21, 2011 · N3661B · Substantial damage
  > Collision with the ground while maneuvering at low altitude for reasons that could not be determined because postaccident examination did not reveal any anomalies that would have precluded normal operation.

## 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 s.case_mkey FROM 'https://openairdocs.org/data/latest/ntsb_events.parquet' s WHERE s."tier2Number" = '000' AND s.case_mkey IN (SELECT case_mkey FROM 'https://openairdocs.org/data/latest/ntsb_events.parquet' WHERE "isDefiningEvent"))
ORDER BY c."eventDate" DESC, c."ntsbNumber" DESC
```

This list as a web page: https://openairdocs.org/ntsb-events/000/sequence?state=MT

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