# Main rotor trans mount

- Type: NTSB finding subsection
- Path: [Aircraft](https://openairdocs.org/ntsb-findings/01) › [Aircraft propeller/rotor](https://openairdocs.org/ntsb-findings/0104) › [Main rotor drive](https://openairdocs.org/ntsb-findings/010463) › Main rotor trans mount
- NTSB code: 01046330
- Cases: 1
- In the probable cause: 1
- Fatal cases: 0
- All cases: https://openairdocs.org/ntsb-findings/01046330/cases.md
- Cases with it in the probable cause: https://openairdocs.org/ntsb-findings/01046330/cases.md?cause=1
- Page: https://openairdocs.org/ntsb-findings/01046330

## Cases per year (in the probable cause / all)

- 2009: 1 / 1

## Defining events in these cases

- [Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330): 1 cases

## Aircraft models (registry)

- [Robinson Helicopter R44](https://openairdocs.org/model/robinson-helicopter-r44): 1 cases

## Other findings in the same cases

- [Document/info production](https://openairdocs.org/ntsb-findings/04013020) (Organizational issues): 1 cases
- [Weight/balance calculations](https://openairdocs.org/ntsb-findings/02061015) (Personnel issues): 1 cases
- [CG/weight distribution](https://openairdocs.org/ntsb-findings/01061040) (Aircraft): 1 cases

## Newest cases

- [NTSB ANC09GA040](https://openairdocs.org/ntsb/ANC09GA040), May 12, 2009: Robinson Helicopter R44 (N7196H), Iliamna, AK, substantial damage. Probable cause: The main rotor transmission mount design, which resulted in an in-flight vibration/oscillation, and damage to the helicopter during an emergency descent and hard landing. Contributing to the accident…

NTSB has coded findings and defining events since 2008; earlier cases used its older occurrence and cause codes and aren't counted.

Findings: https://openairdocs.org/ntsb-findings.md. Defining events: https://openairdocs.org/ntsb-events.md. Phases of flight: https://openairdocs.org/ntsb-phases.md. Every investigation, filtered by finding, event, phase, state, year or model: https://openairdocs.org/ntsb.md (for example ?state=MI&fatal=1).

NTSB's definitions: Accident and incident, 49 CFR 830.2 (https://www.ecfr.gov/current/title-49/subtitle-B/chapter-VIII/part-830/subpart-A/section-830.2), CICTT occurrence categories (PDF) (https://www.ntsb.gov/safety/data/Documents/datafiles/OccurrenceCategoryDefinitions.pdf), CICTT phases of flight (PDF) (https://www.ntsb.gov/safety/data/Documents/datafiles/PhaseofFlightDefinitions.pdf), and NTSB coding manual, before 2008 (PDF) (https://www.ntsb.gov/GILS/Documents/codman.pdf). NTSB publishes no definitions for its findings, only their names.

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