# NTSB investigations: Schweizer 269C-1: Ground resonance

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 ERA25LA255](https://openairdocs.org/ntsb/ERA25LA255.md): Schweizer 269C · Madisonville, KY · Accident · Minor injuries · Class 4 · Limited · Final report · Jul 2, 2025 · N21385 · Substantial damage
  > The pilot’s failure to take the appropriate corrective action for ground resonance, which resulted in a loss of helicopter control.
- [NTSB ERA16LA261](https://openairdocs.org/ntsb/ERA16LA261.md): Schweizer 269C · Calhoun, GA · Accident · No injuries · Limited investigation · Final report · Jul 16, 2016 · N6148D · Substantial damage
  > The helicopter owner’s failure to ensure the helicopter’s airworthiness and the inadequate inspection and maintenance of the helicopter's landing gear dampers, which resulted in ground resonance during throttle application. Contributing to the damage of the…
- [NTSB ERA14LA293](https://openairdocs.org/ntsb/ERA14LA293.md): Schweizer 269C-1 · Allentown, PA · Accident · Minor injuries · Limited investigation · Final report · Jun 17, 2014 · N152CC · Substantial damage
  > Inadequate inspection and maintenance of the helicopter’s landing gear dampers, which resulted in ground resonance during helicopter shutdown.
- [NTSB CEN12LA353](https://openairdocs.org/ntsb/CEN12LA353.md): Schweizer 269C-1 · Chesterfield, MO · Accident · No injuries · Limited investigation · Final report · May 26, 2012 · N345MH · Substantial damage
  > The undercharged and overcharged landing gear dampers, which allowed initiation of the ground resonance event from which the pilot was unable to recover due to his limited experience in helicopters. Contributing to the accident was the ineffective damper…

## 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 ('8059504')
    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" = '232' 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/232/sequence?model=8059504

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