# NTSB CEN12LA039: Eurocopter AS 350 B2, N183EH, South Pass 93A, October 7, 2011

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: October 7, 2011, 14:30 local (19:30 UTC)
- Place: South Pass 93A
- Coordinates: 28.660833, -89.408058
- Nearby events: https://openairdocs.org/map.md?lat=28.6608&lon=-89.4081&mi=10
- Phase of flight: [Standing](https://openairdocs.org/ntsb-phases/150) (OpenAirDocs' grouping)
- Defining event: [Standing-engine(s) start-up: Miscellaneous/other](https://openairdocs.org/ntsb-events/900)
- Highest injury: No injuries
- Injuries: 3 uninjured
- Status: Completed, report November 26, 2012
- Report: Approved by Office Director
- NTSB office: Central Region
- Parties: Bureau d’Enquêtes et d’Analyses (BEA), American Eurocopter
- NTSB case key (mKey): 82164
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN12LA039
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/82164/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=82164
- Page: https://openairdocs.org/ntsb/CEN12LA039

## Probable cause

Improper centering of the cyclic during a start in gusty wind conditions.

## Findings

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

- [Wind: updraft](https://openairdocs.org/ntsb-findings/03034030): Environmental issues › Conditions/weather/phenomena · Effect on equipment; cases with it: [Eurocopter AS 350 B2, 1 case](https://openairdocs.org/ntsb-findings/03034030/cases.md?model=8680950), [All aircraft, 14 cases](https://openairdocs.org/ntsb-findings/03034030/cases.md)
- [Main rotor system: main rotor blade system](https://openairdocs.org/ntsb-findings/01046210): Aircraft › Aircraft propeller/rotor · Incorrect use/operation (probable cause); cases with it: [Eurocopter AS 350 B2, 2 cases](https://openairdocs.org/ntsb-findings/01046210/cases.md?model=8680950), [All aircraft, 60 cases](https://openairdocs.org/ntsb-findings/01046210/cases.md)
- [Action: incorrect action selection](https://openairdocs.org/ntsb-findings/02041010): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Eurocopter AS 350 B2, 1 case](https://openairdocs.org/ntsb-findings/02041010/cases.md?model=8680950), [All aircraft, 397 cases](https://openairdocs.org/ntsb-findings/02041010/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) start-up: Miscellaneous/other](https://openairdocs.org/ntsb-events/900) (defining event); cases with it: [Eurocopter AS 350 B2, 4 cases](https://openairdocs.org/ntsb-events/900/sequence.md?model=8680950), [All aircraft, 1,556 cases](https://openairdocs.org/ntsb-events/900/sequence.md)

## Analysis

During an engine start on a helipad, the helicopter's main rotor blade contacted the tailboom, which resulted in substantial damage to the tailboom. The reported wind about the time of the accident was about 23 knots. The pilot reported that when the wind was from the east, as it was at the time of the accident, wind contact with a generator room west of the helipad resulted in occasional updrafts on the helipad. An examination of the helicopter did not reveal any preexisting anomalies that would have precluded normal operation. In the helicopter's flight manual checklist for the "Checks Before Starting the Engine," the helicopter's cyclic is to be in the neutral position and the cyclic stick friction lock adjusted. Note 1 of the checklist states, "In strong wind, apply a little forward cyclic and accelerate the engine, up to approx. 320 rpm, as fast as in compatible with t4 limitations, then follow normal procedure." A review of accidents involving the same make and model helicopters, revealed that in all of the recorded tail boom strikes by main rotor blades during start, two conditions needed to be present: cyclic not centered and air turbulence pushing strongly on the main rotor blades.

## Factual narrative

On October 7, 2011, about 1430 central daylight time, a Eurocopter AS350 B2, sustained substantial damage to the section during an engine start on the off-shore oil platform (South Pass 93A), Gulf of Mexico. The commercial pilot and the two passengers were not injured. The helicopter was registered to and operated by ERA Helicopters under the provisions of 14 Code of Federal Regulations Part 135 as an on-demand air taxi. Visual meteorological conditions prevailed for the flight, which operated on a company visual flight rules flight plan. The flight was originating at the time of the accident. According to a statement provided by the pilot, the helicopter’s nose was facing towards the wind that was measured by a velometer to be about 23 knots. The pilot centered and locked the controls prior to engine start in accordance with the helicopter’s checklist. About 22 Ng and three full main rotor rotations, the pilot felt chatter/vibrations from the helicopter. The pilot shut down the engine and found damage consistent with a main rotor blade strike to. The helicopter's tail rotor drive shaft had been distorted and damaged. The helicopter’s helipad was elevated from the main platform with a generator room west (downwind) of the helipad. The pilot reported that when the wind was from the east, the wind contacts the generator room and can cause occasional updrafts on the helideck. In the helicopter's flight manual's checklist for the "Checks Before Starting the Engine", the helicopter's cyclic is to be in the neutral position and the cyclic stick friction lock adjusted. Note 1 of the "Starting" checklist states, "In strong wind, apply a little forward cyclic and accelerate the engine, up to approx. 320 rpm, as fast as in compatible with t4 limitations, then follow normal procedure." An examination of the helicopter did not discover any preexisting anomalies with the helicopter which would have precluded normal operation of the helicopter. It could not be determined if the controls had been locked improperly or if winds displaced the main rotor blades during the engine start. A review of accidents involving AS350 helicopters by the Bureau d'Enquêtes et d'Analyses (BEA), revealed that in all recorded tail boom strikes by main rotor blades during start two conditions needed to be present: cyclic not centered and air turbulence pushing strongly on the main rotor blades.

## Aircraft

- Registration: [N183EH](https://openairdocs.org/aircraft/N183EH), registered now, S/N 2752, built 1993 (OpenAirDocs)
- Reported make and model: EUROCOPTER AS 350 B2
- Registry model: [Eurocopter AS 350 B2](https://openairdocs.org/model/eurocopter-as-350-b2) (registry code 8680950) (OpenAirDocs)
- Registry engine: [Turbomeca ARRIEL-1SER](https://openairdocs.org/engine/turbomeca-arriel-1ser) (registry code 60030, turbo-shaft) (OpenAirDocs)
- Category: Helicopter
- Serial number: 2752
- Engines: TURBOMECA SD2 732 horsepower turbo shaft
- Damage: Substantial damage
- Flight: Part 135
- Operator: Era Helicopters LLC
- Registered owner: Era Helicopters LLC
- Airworthiness certificate: Standard, Normal
- Departed: South Pass 93A, GM
- Flight plan: Company VFR
- Airport: South Pass 93A

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 29; injuries: none; flight instructor, commercial; instrument ratings: helicopter; medical: class 2, without waivers/limitations; last flight review May 10, 2011; seat: right; flight hours: 4,800 total, 3,500 in this make and model, 4,600 as pilot in command, 350 in the last 90 days, 50 in the last 30 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 86° at 22 knots, gusting 27
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 81 °F

## FAA reports on this event (1)

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

- [Incident 20111007023849I](https://openairdocs.org/incident/20111007023849I), Oct 7, 2011: Eurocopter AS 350 B2, Minor damage. During start-up Offshore one main rotor blade flexed down and made contact with the tailboom. Aircraft was shut down and maintenance was called.

## Docket (4 files)

The files NTSB released with the investigation on August 7, 2012, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=82164. 1.3 MB in all.

- Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 790 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40362542&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF
- Witness Statement: Pilot's additional statement (item 2, .PDF, 426 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40362543&FileExtension=.PDF&FileName=Witness%20Statement%3A%20Pilot%27s%20additional%20statement-Redacted.PDF
- Correspondence: Director of Safety, Era Helicopters (item 3, .PDF, 51 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40362544&FileExtension=.PDF&FileName=Correspondence%3A%20Director%20of%20Safety,%20Era%20Helicopters-Master.PDF
- Miscellaneous: AS350 flight manual excerpt (item 4, .PDF, 67 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40374783&FileExtension=.PDF&FileName=Miscellaneous%3A%20AS350%20flight%20manual%20excerpt-Master.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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