# NTSB investigations: Hiller UH-12E: Loss of control in flight

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 WPR24LA262](https://openairdocs.org/ntsb/WPR24LA262.md): Hiller UH-12E · Bonners Ferry, ID · Accident · No injuries · Class 4 · Limited · Final report · Jul 24, 2024 · N3375T · Substantial damage
  > The pilot’s improper selection of a landing site, which resulted in a main rotor strike. Contributing to the accident was the pilot’s improper performance planning and altitude selection over water, which resulted in an rpm droop.
- [NTSB ERA21LA386](https://openairdocs.org/ntsb/ERA21LA386.md): Hiller UH-12E · Millen, GA · Accident · Minor injuries · Class 3 · Limited · Final report · Sep 29, 2021 · N430NR · Substantial damage
  > The improper reassembly of the tail rotor gearbox following maintenance, which resulted in fatigue failure of the input pinion gear shaft, and the subsequent loss of tail rotor drive.
- [NTSB WPR21LA354](https://openairdocs.org/ntsb/WPR21LA354.md): Hiller UH-12E · Bovill, ID · Accident · No injuries · Class 3 · Limited · Final report · Sep 23, 2021 · N5334V · Substantial damage
  > A loss of helicopter control for undetermined reasons based on the available evidence for this accident.
- [NTSB WPR11LA244](https://openairdocs.org/ntsb/WPR11LA244.md): Hiller UH-12E · Stockton, CA · Accident · No injuries · Limited investigation · Final report · Jun 1, 2011 · N68012 · Substantial damage
  > The pilot's failure to maintain clearance from obstacles.
- [NTSB WPR10FA440](https://openairdocs.org/ntsb/WPR10FA440.md): Hiller UH 12E · Kamiah, ID · Accident · 3 fatal · Field investigation · Final report · Aug 31, 2010 · N67264 · Substantial damage
  > In-flight impact of a passenger's metal clipboard with the helicopter’s tail rotor, which resulted in destruction of the tail rotor and subsequent loss of control of the helicopter. The original location of the clipboard and how it became free could not be…
- [NTSB CHI08CA252](https://openairdocs.org/ntsb/CHI08CA252.md): Hiller UH-12E · Cokato, MN · Accident · No injuries · Data collection · Final report · Aug 15, 2008 · N945HA · Substantial damage
  > The pilot did not visually identify and maintain clearance with the power lines, and the pilot's inability to maintain control of the helicopter once it contacted the power lines. Factors associated with the accident were the low altitude operations being…
- [NTSB DEN08LA071](https://openairdocs.org/ntsb/DEN08LA071.md): Hiller UH-12E · La Porte, TX · Accident · Minor injuries · Limited investigation · Final report · Apr 4, 2008 · N40289 · Substantial damage
  > The loss of tail rotor effectiveness. Contributing factors were the sudden windshift to a tailwind, and the pilot initiating a hovering turn in ground effect.

## 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."mKey" IN (SELECT x.case_mkey FROM 'https://openairdocs.org/data/latest/ntsb_aircrafts.parquet' x WHERE x.aircraft_model_code IN ('4360122', '4360137')
    AND EXISTS (SELECT 1 FROM 'https://openairdocs.org/data/latest/ntsb_events.parquet' s WHERE s.case_mkey = x.case_mkey AND s.aircrafts_position = x.position AND s."tier2Number" = '240' 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/240/sequence?model=4360122

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