# Accumulator, main

- Type: NTSB finding subsection
- Path: [Aircraft](https://openairdocs.org/ntsb-findings/01) › [Aircraft systems](https://openairdocs.org/ntsb-findings/0102) › [Hydraulic power system](https://openairdocs.org/ntsb-findings/010229) › Accumulator, main
- NTSB code: 01022911
- Cases: 3
- In the probable cause: 2
- Fatal cases: 1
- All cases: https://openairdocs.org/ntsb-findings/01022911/cases.md
- Cases with it in the probable cause: https://openairdocs.org/ntsb-findings/01022911/cases.md?cause=1
- Page: https://openairdocs.org/ntsb-findings/01022911

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

- 2009: 1 / 1
- 2014: 0 / 1
- 2022: 1 / 1

## Defining events in these cases

- [Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330): 2 cases
- [Loss of control in flight](https://openairdocs.org/ntsb-events/240): 1 cases

## Aircraft models (registry)

- [Eurocopter AS 350 B2](https://openairdocs.org/model/eurocopter-as-350-b2): 1 cases
- [Cessna T210L](https://openairdocs.org/model/cessna-t210l): 1 cases
- [Cessna 210B](https://openairdocs.org/model/cessna-210b): 1 cases

## Other findings in the same cases

- [Not determined, general](https://openairdocs.org/ntsb-findings/05000000) (Not determined): 1 cases
- [Forgotten action/omission](https://openairdocs.org/ntsb-findings/02041035) (Personnel issues): 1 cases
- [Monitoring equip/instruments](https://openairdocs.org/ntsb-findings/02021525) (Personnel issues): 1 cases
- [Yaw control](https://openairdocs.org/ntsb-findings/01062024) (Aircraft): 1 cases
- [Lateral/bank control](https://openairdocs.org/ntsb-findings/01062023) (Aircraft): 1 cases
- [Pitch control](https://openairdocs.org/ntsb-findings/01062022) (Aircraft): 1 cases
- [Rotorcraft servo system](https://openairdocs.org/ntsb-findings/01046730) (Aircraft): 1 cases
- [Main landing gear](https://openairdocs.org/ntsb-findings/01023210) (Aircraft): 1 cases
- [Hydraulic, main system](https://openairdocs.org/ntsb-findings/01022910) (Aircraft): 1 cases

## Newest cases

- [NTSB CEN22LA378](https://openairdocs.org/ntsb/CEN22LA378), Aug 9, 2022: Cessna 210B (N9637X), Clinton, AR, substantial damage. Probable cause: A fatigue crack in the hydraulic actuator, which resulted in the loss of hydraulic fluid and the pilot’s inability to fully extend the landing gear.
- [NTSB WPR14FA137](https://openairdocs.org/ntsb/WPR14FA137), Mar 18, 2014: Eurocopter AS 350 B2 (N250FB), Seattle, WA, destroyed, 2 fatal. Probable cause: 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…
- [NTSB CEN09LA417](https://openairdocs.org/ntsb/CEN09LA417), Jul 1, 2009: Cessna T210L (N2118S), Santa Teresa, NM, substantial damage. Probable cause: The failure of the landing gear accumulator seal for undetermined reasons. Contributing to the accident was the pilot’s failure to confirm the status of the landing gear.

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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