# NTSB investigations: Rotorcraft servo system

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 WPR20LA211](https://openairdocs.org/ntsb/WPR20LA211.md): Bell UH1H · Payson, AZ · Accident · 1 fatal · Class 3 · Limited · Final report · Jul 7, 2020 · N623PB · Destroyed
  > A flight control malfunction due to either a hydraulic hardover or a flight control stiffness event, which resulted in a loss of control.
- [NTSB ERA15FA164](https://openairdocs.org/ntsb/ERA15FA164.md): Robinson Helicopter R44 II · Orlando, FL · Accident · 3 fatal · Field investigation · Final report · Mar 22, 2015 · N30242 · Destroyed
  > An inflight loss of control due to the likely detachment of the forward left servo control tube upper rod end attachment bolt.
- [NTSB WPR14FA137](https://openairdocs.org/ntsb/WPR14FA137.md): Eurocopter AS 350 B2 · Seattle, WA · Accident · 2 fatal · Field investigation · Final report · Mar 18, 2014 · N250FB · Destroyed
  > The loss of helicopter control due to a loss of hydraulic boost to the tail rotor pedal controls at takeoff, followed by a loss of hydraulic boost to the main rotor controls after takeoff. The reason for the loss of hydraulic boost to the main and tail rotor…
- [NTSB ERA12FA563](https://openairdocs.org/ntsb/ERA12FA563.md): Aerospatiale AS 355F1 · West Windsor, NJ · Accident · 1 fatal · Field investigation · Final report · Sep 15, 2012 · N58020 · Substantial damage
  > Disconnection of the upper rod end from the fore/aft servo due to severely worn threads, which resulted in a loss of control and separation of a main rotor blade during cruise flight. Contributing to the accident were incorrect maintenance procedures and…
- [NTSB DCA12MA020](https://openairdocs.org/ntsb/DCA12MA020.md): Eurocopter France AS350B2 · Las Vegas, NV · Accident · 5 fatal · Class 1 · Major · Final report · Dec 8, 2011 · N37SH · Destroyed
  > Sundance Helicopters’ inadequate maintenance of the helicopter, including (1) the improper reuse of a degraded self-locking nut, (2) the improper or lack of installation of a split pin, and (3) inadequate postmaintenance inspections, which resulted in the…
- [NTSB ERA09LA051](https://openairdocs.org/ntsb/ERA09LA051.md): Robinson Helicopter R44 · San Juan, PR · Accident · Serious injuries · Limited investigation · Final report · Nov 12, 2008 · N452JM · Substantial damage
  > The detachment of the forward left servo control tube upper rod end attachment bolt during a hover due to separation of its retaining nut for undetermined reasons.

## 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 f.case_mkey FROM 'https://openairdocs.org/data/latest/ntsb_findings.parquet' f WHERE starts_with(f."findingCode", '01046730'))
ORDER BY c."eventDate" DESC, c."ntsbNumber" DESC
```

This list as a web page: https://openairdocs.org/ntsb-findings/01046730/cases

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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.