# NTSB investigations, 2011, MT: VFR encounter with IMC

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 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.

## 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 year(c."eventDate") = 2011
  AND 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" = '401' 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/401/sequence?state=MT&year=2011

---
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, except the copies of manufacturers’ service documents, which belong to their rights holders.