# NTSB investigations: Schweizer 269C: 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 ERA23LA284](https://openairdocs.org/ntsb/ERA23LA284.md): Schweizer 269C · Macclenny, FL · Accident · Minor injuries · Class 3 · Limited · Final report · Jul 1, 2023 · N9WZ · Substantial damage
  > The improper maintenance of the landing gear dampers and main rotor elastomeric dampers, resulting in ground resonance during an unsuccessful takeoff attempt with the helicopter near its maximum gross weight for the density altitude.
- [NTSB WPR18LA170](https://openairdocs.org/ntsb/WPR18LA170.md): Schweizer 269C · Las Vegas, NV · Accident · Minor injuries · Class 3 · Limited · Final report · Jun 13, 2018 · N557DC · Substantial damage
  > The pilot’s failure to take the appropriate corrective action for ground resonance, which resulted in a loss of helicopter control.
- [NTSB CEN14LA269](https://openairdocs.org/ntsb/CEN14LA269.md): Schweizer 269C · Temple, TX · Accident · No injuries · Limited investigation · Final report · May 31, 2014 · N902CP · Substantial damage
  > Ground resonance due to maintenance personnel’s improper inspection of the landing gear dampers, which resulted in the dampers operating outside of allowable limits.
- [NTSB CEN12LA343](https://openairdocs.org/ntsb/CEN12LA343.md): Schweizer 269C · Denver, CO · Accident · No injuries · Limited investigation · Final report · Jun 2, 2012 · N2196F · Substantial damage
  > The inadequately overhauled landing gear dampers that allowed initiation of a ground resonance event from which the pilot was unable to recover. Contributing to the accident was the overhaul facility's failure to identify the overcharged dampers and a lack of…
- [NTSB ERA11LA428](https://openairdocs.org/ntsb/ERA11LA428.md): Schweizer 269C · Darlington, MD · Accident · Minor injuries · Limited investigation · Final report · Jul 29, 2011 · N39SH · Substantial damage
  > Inadequate maintenance of the helicopter's landing gear dampers, which resulted in a main rotor out-of-balance condition and ground resonance encounter.
- [NTSB NYC08CA195](https://openairdocs.org/ntsb/NYC08CA195.md): Schweizer 269C · Mt. Olive, AL · Accident · Minor injuries · Data collection · Final report · May 27, 2008 · N368HF · Substantial damage
  > The flight instructor's inadequate remedial action following an encounter with ground resonance.

## 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 ('8059502')
    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=8059502

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