# NTSB CEN09LA198: Bell 206, N410RL, Galliano, LA, March 2, 2009

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: March 2, 2009, 07:20 local (12:20 UTC)
- Place: Galliano, LA
- Coordinates: 29.437778, -90.256668 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=29.4378&lon=-90.2567&mi=10
- Phase of flight: [Standing](https://openairdocs.org/ntsb-phases/150) (OpenAirDocs' grouping)
- Defining event: [Standing-engine(s) operating: Flight control sys malf/fail](https://openairdocs.org/ntsb-events/333)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report July 28, 2009
- Report: Approved by Office Director
- NTSB office: Central Region
- Parties: FAA/FSDO
- NTSB case key (mKey): 73466
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN09LA198
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/73466/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=73466
- Page: https://openairdocs.org/ntsb/CEN09LA198

## Probable cause

The failure of the tail rotor driveshaft and coupling during engine start due to the mechanic's failure to properly reattach the tail rotor driveshaft and coupling during maintenance.

## Findings

NTSB's coded findings; those marked are part of the probable cause.

- [Action: forgotten action/omission](https://openairdocs.org/ntsb-findings/02041035): Personnel issues › Action/decision · Maintenance personnel (probable cause); cases with it: [Bell Helicopter Textron Canada 206L-4, 1 case](https://openairdocs.org/ntsb-findings/02041035/cases.md?model=1181455), [All aircraft, 440 cases](https://openairdocs.org/ntsb-findings/02041035/cases.md)

## Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event best describes what happened.

- [Standing-engine(s) operating: Flight control sys malf/fail](https://openairdocs.org/ntsb-events/333) (defining event); cases with it: [Bell Helicopter Textron Canada 206L-4, 1 case](https://openairdocs.org/ntsb-events/333/sequence.md?model=1181455), [All aircraft, 410 cases](https://openairdocs.org/ntsb-events/333/sequence.md)

## Analysis

The commercial pilot was starting the single-engine helicopter's engine when he heard a loud bang and vibration. He immediately shut down the engine and exited the helicopter. Examination of the helicopter revealed that the tail rotor driveshaft and coupling had severed just forward of the gearbox, which resulted in substantial damage to the tail boom. The helicopter had undergone recent maintenance to the tail rotor gearbox input seal which included the removal of the tail rotor drive shaft from the coupling. When the two components were reattached, the mechanic only hand-tightened the bolts, figuring additional maintenance was still planned for the gearbox. He then installed the tail rotor drive shaft shaft cover. The mechanic moved on to another project and did not make a logbook entry of the work that he had completed or that the bolts were only hand-tightened. Another mechanic later performed additional maintenance to the gearbox, but the bolts were not checked since the maintenance manual did not require the removal of the tail rotor driveshaft cover. A .2-hour maintenance flight check was conducted and the helicopter was returned to service. The accident occurred on first engine start after it had been returned to service.

## Factual narrative

On March 2, 2009, at 0720 central daylight time, a Bell 206L-3, N401RL, was damaged when the tail rotor drive shaft and coupling severed while the helicopter was sitting on the ramp with the engine running. The helicopter was operated by and registered to Rotorcraft Leasing Company, LLC, Broussard, Louisiana. The commercial pilot was not injured. Visual meteorological conditions prevailed and no flight plan was filed for the ferry flight conducted under 14 Code of Federal Regulations Part 91. According to the operator, the pilot heard a loud bang and vibration shortly after starting the engine. He immediately shut down the engine, and exited the helicopter. Examination of the helicopter revealed that the tail rotor drive shaft and coupling had severed just forward of the gearbox, which resulted in substantial damage to the tail boom. The helicopter had undergone recent maintenance to the tail rotor gearbox input seal which included the removal of the tail rotor drive shaft from the coupling. When the two components were reattached, the mechanic only hand tightened the bolts, figuring additional maintenance was still planned for the gearbox. He then installed the tailrotor drive shaft cover. The mechanic moved onto another project and did not make a logbook entry of the work that he had completed or that the bolts were only hand tightened. Another mechanic later performed additional maintenance to the gearbox, but the bolts were not checked since the maintenance manual did not require the removal of the tail rotor driveshaft cover. A .2-hour maintenance flight check was conducted and the helicopter was returned to service. The accident occurred on first engine start after it had been returned to service.

## Aircraft

- Registration: [N410RL](https://openairdocs.org/deregistered/N410RL-2020-10-07), registration cancelled 2020-10-07, S/N 52310, built 2005 (OpenAirDocs)
- Reported make and model: BELL 206 (L4)
- Registry model: [Bell Helicopter Textron Canada 206L-4](https://openairdocs.org/model/bell-helicopter-textron-canada-206l-4) (registry code 1181455) (OpenAirDocs)
- Registry engine: [Rolls-Royce 250 20&30 series](https://openairdocs.org/engine/rolls-royce-250-20-30-series) (registry code 54584, turbo-shaft) (OpenAirDocs)
- Category: Helicopter
- Airframe hours: 5118
- Engines: Rolls Royce 260c30 850 horsepower turbo shaft
- Damage: Substantial damage
- Flight: Ferry, Part 91
- Operator: Rotorcraft Leasing Company, LLC
- Registered owner: Rotorcraft Leasing Company, LLC
- Airworthiness certificate: Standard, Transport
- Last inspection: AAIP, February 15, 2009
- Departed: GAO, Galliano, LA
- Destination: GAO, Galliano, LA
- Flight plan: Unknown
- Airport: GAO, South Lafourche Leonard Miller

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 32; injuries: none; commercial; instrument ratings: helicopter; medical: class 2, without waivers/limitations; last flight review October 20, 2008; seat: right; flight hours: 1,292 total, 81 in this make and model, 1,250 as pilot in command, 36 in the last 90 days, 15 in the last 30 days

## Weather

- Conditions: Visual (VMC), Day
- Wind: variable at 7 knots
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 30 °F, dew point 30 °F
- Observed at: GAO

## FAA reports on this event (1)

The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs).

- [Accident 20090302002519A](https://openairdocs.org/incident/20090302002519A), Mar 2, 2009: Bell 206L4, Galliano, LA, Substantial damage. (-23) A mechanic had performed maintenance on the tail rotor drive shaft, to be exact, the nr 7 drive shaft and the whole gar-lock seal cover input assembly…

## Docket (3 files)

The files NTSB released with the investigation on May 29, 2009, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=73466. 15.3 MB in all.

- Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 749 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40313655&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF
- Written Statement-Maintenance Personnel (item 2, .PDF, 10.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40313656&FileExtension=.PDF&FileName=Written%20Statement-Maintenance%20Personnel-Redacted.PDF
- Written Statement: Rotorcraft Leasing Corp (item 3, .PDF, 3.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40313657&FileExtension=.PDF&FileName=Written%20Statement%3A%20Rotorcraft%20Leasing%20Corp-Redacted.PDF

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

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