# NTSB WPR23LA339: Eurocopter France AS350B2, N350WW, Silverton, WA, September 9, 2023 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 4 · Limited · Final report - Date: September 8, 2023, 20:28 local (Sep 9, 2023, 03:28 UTC) - Place: Silverton, WA · Lake shore - Coordinates: 48.03041, -121.53615 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=48.0304&lon=-121.5362&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering-low-alt flying: Loss of visual reference](https://openairdocs.org/ntsb-events/402) - Highest injury: No injuries - Injuries: 5 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 4 - Basic report with no Prelim publish - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 193047 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR23LA339 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/193047/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=193047 - Page: https://openairdocs.org/ntsb/WPR23LA339 ## Probable cause The pilot’s failure to maintain visual reference and altitude while maneuvering over a lake during dusk conditions, which resulted in the helicopter impacting water. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Performance/control parameters: altitude](https://openairdocs.org/ntsb-findings/01062012): Aircraft › Aircraft oper/perf/capability · Not attained/maintained; cases with it: [All aircraft, 1,310 cases](https://openairdocs.org/ntsb-findings/01062012/cases.md) - [Light condition: low light](https://openairdocs.org/ntsb-findings/03036015): Environmental issues › Conditions/weather/phenomena · Contributed to outcome (probable cause); cases with it: [All aircraft, 36 cases](https://openairdocs.org/ntsb-findings/03036015/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Maneuvering-low-alt flying: Loss of visual reference](https://openairdocs.org/ntsb-events/402) (defining event); cases with it: [All aircraft, 242 cases](https://openairdocs.org/ntsb-events/402/sequence.md) - [Maneuvering: Controlled flight into terr/obj (CFIT)](https://openairdocs.org/ntsb-events/120); cases with it: [All aircraft, 1,074 cases](https://openairdocs.org/ntsb-events/120/sequence.md) ## Analysis The pilot reported that he was landing the helicopter on the shoreline of a lake, during low light, dusk conditions. During the approach to the shoreline, he began maneuvering to slow the helicopter down and descend over the open water and that his attention was fully outside of the helicopter, when he saw a light from the intended landing zone get brighter, and the area around the helicopter suddenly got darker. The helicopter subsequently struck the surface of the lake, rolled inverted, and sank in about 80 ft. of water. The pilot and the passengers exited the helicopter and were rescued by a good Samaritan before it sank. The helicopter sustained substantial damage to the main rotor drive system and tail boom assembly. The pilot reported that there are no mechanical malfunctions or failures that would have precluded normal operations. ## Aircraft - Registration: N350WW (not matched to a registry record) - Reported make and model: EUROCOPTER FRANCE AS350B2 - Category: Helicopter - Serial number: 2228 - Year built: 1989 - Airframe hours: 11884.1 - Engines: Honeywell LTS101-700D-2 742 hp turbo shaft - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Worldwind Helicopters Inc - Airworthiness certificate: Standard, Normal - Last inspection: Unknown, September 8, 2023 - Departed: AWO, Arlington, WA - Destination: Same as departure - Equipment: ADS-B, Satellite tracking device, Electronic flight bag or handheld device ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 63; injuries: none; private, commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: helicopter; medical: class 2, with waivers/limitations; last flight review June 5, 2023; seat: right; restraint: 4-point; flight hours: 3,790 total, 3,025 in this make and model, 3,523 as pilot in command, 65 in the last 90 days, 15 in the last 30 days, 3 in the last 24 hours ## Weather - Conditions: Visual (VMC), Dusk - Wind: 50° at 2 knots - Lowest ceiling: none - Temperature: 64 °F, dew point 55 °F - Observed at: CWZA, 23 nm away - METAR: CWZA 090300Z AUTO 05002KT 18/13 RMK AO1 3002 SLP195 T01790131 50001 ## 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 20230908014819A](https://openairdocs.org/incident/20230908014819A), Sep 8, 2023: Eurocopter France AS350B2, Silverton, WA, Substantial damage. Aircraft left arrington airport with four pax on board to drop at copper river, second flight with pax to this lake that day, time as coming in for landing at… ## Docket (2 files) The files NTSB released with the investigation on April 30, 2024, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=193047. 3.6 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 11 pages, 2.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16100084&FileExtension=pdf&FileName=6120_1-N350WW-F_Redacted-Rel.pdf - Photos (item 2, PDF, 2 pages, 1.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16473034&FileExtension=pdf&FileName=Photos%20for%20WPR23LA339-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.