# NTSB ANC18CA056: Eurocopter AS 350 B3, N354LA, Kobuk, AK, July 25, 2018 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Class 4 · Data collection · Final report - Date: July 25, 2018, 10:45 local (18:45 UTC) - Place: Kobuk, AK - Coordinates: 66.935554, -156.77305 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=66.9356&lon=-156.7731&mi=10 - Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping) - Defining event: [Takeoff: Dynamic rollover](https://openairdocs.org/ntsb-events/231) - Highest injury: Minor injuries - Injuries: 1 minor - Status: Completed - Report: Approved by Office Director - Investigation class: Class 4 - Basic report with no Prelim publish - NTSB office: Alaska Regional Office - Parties: Federal Aviation Administration (FAA) - NTSB case key (mKey): 97858 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC18CA056 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/97858/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=97858 - Page: https://openairdocs.org/ntsb/ANC18CA056 ## Probable cause The pilot's inadvertent dynamic rollover during takeoff. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Eurocopter AS 350 B3, 14 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=8680954), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) - [Performance/control parameters](https://openairdocs.org/ntsb-findings/01062000): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Eurocopter AS 350 B3, 4 cases](https://openairdocs.org/ntsb-findings/01062000/cases.md?model=8680954), [All aircraft, 1,269 cases](https://openairdocs.org/ntsb-findings/01062000/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Takeoff: Dynamic rollover](https://openairdocs.org/ntsb-events/231) (defining event); cases with it: [Eurocopter AS 350 B3, 2 cases](https://openairdocs.org/ntsb-events/231/sequence.md?model=8680954), [All aircraft, 161 cases](https://openairdocs.org/ntsb-events/231/sequence.md) ## Analysis The commercial pilot of the helicopter was transporting equipment in support of remote mining activities using a 100-foot long-line. During takeoff, and while preparing to lift the external sling load, he inadvertently allowed the helicopter to drift laterally to the right and the right skid struck the ground, resulting in a dynamic rollover. The helicopter continued to roll to the right, and the main rotor blades struck the ground. The helicopter subsequently came to rest on its right side, sustaining substantial damage to the main rotor drive system, fuselage, and tail boom. The pilot sustained minor injuries, and reported that there were no preaccident mechanical failures or malfunctions with the helicopter that would have precluded normal operation. ## Aircraft - Registration: [N354LA](https://openairdocs.org/aircraft/N354LA), registered now, S/N 3285 (OpenAirDocs) - Reported make and model: EUROCOPTER AS 350 B3 - Registry model: [Eurocopter AS 350 B3](https://openairdocs.org/model/eurocopter-as-350-b3) (registry code 8680954) (OpenAirDocs) - Category: Helicopter - Serial number: 3285 - Year built: 2000 - Airframe hours: 6472.8 - Engines: Safran Arriel 847 hp turbo shaft - Damage: Substantial damage - Flight: Part 133 - Operator: Trans Aero Helicopters - Registered owner: Roberts Aircraft Co - Airworthiness certificate: Standard, Normal - Last inspection: Continuous airworthiness, July 13, 2018 - Departed: Kobuk, AK - Destination: Kobuk, AK - Flight plan: Company VFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 47; injuries: minor; flight instructor, commercial; airplane ratings: single-engine land; instrument ratings: helicopter; medical: class 2, with waivers/limitations; last flight review March 23, 2018; seat: right; restraint: 4-point; flight hours: 5,061 total, 225 in this make and model, 4,322 as pilot in command, 193 in the last 90 days, 117 in the last 30 days, 2 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 175° at 15 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 66 °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). - [Accident 20180725017949A](https://openairdocs.org/incident/20180725017949A), Jul 25, 2018: Eurocopter AS 350 B3, Kobuk, AK, Substantial damage. The pilot, [privacy data omitted] was getting ready to sling load a box full of core samples from a remote area northeast of Kobuk Alaska. As he lifted off and… ## Docket (2 files) The files NTSB released with the investigation on April 2, 2021, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=97858. 4.1 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 9 pages, 3.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11637126&FileExtension=pdf&FileName=6120%20ANC18CA056%20signed_Redacted-Rel.pdf - Photo array (item 2, PDF, 3 pages, 3 photos, 682 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11637116&FileExtension=pdf&FileName=ANC18CA056%20Photo%20Array-Rel.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. --- 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.