# NTSB GAA18CA289: Aerospatiale AS350 B2 Ecureuil, N288CH, Yakutat, AK, May 18, 2018 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: May 18, 2018, 15:00 local (23:00 UTC) - Place: Yakutat, AK - Coordinates: 59.083332, -138.200271 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=59.0833&lon=-138.2003&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 October 24, 2018 - Report: Approved by Office Director - NTSB office: General Aviation Accidents - Parties: FAA - NTSB case key (mKey): 97290 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=GAA18CA289 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/97290/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=97290 - Page: https://openairdocs.org/ntsb/GAA18CA289 ## Probable cause The helicopter’s movement during startup in gusting wind conditions, which resulted in the main rotor striking the tailboom. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Performance/control parameters](https://openairdocs.org/ntsb-findings/01062000): Aircraft › Aircraft oper/perf/capability · Attain/maintain not possible (probable cause); cases with it: [Aerospatiale AS350 B2 ECUREUIL, 1 case](https://openairdocs.org/ntsb-findings/01062000/cases.md?model=8680813), [All aircraft, 1,269 cases](https://openairdocs.org/ntsb-findings/01062000/cases.md) - [Wind: gusts](https://openairdocs.org/ntsb-findings/03034045): Environmental issues › Conditions/weather/phenomena · Effect on operation; cases with it: [Aerospatiale AS350 B2 ECUREUIL, 1 case](https://openairdocs.org/ntsb-findings/03034045/cases.md?model=8680813), [All aircraft, 1,199 cases](https://openairdocs.org/ntsb-findings/03034045/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: [Aerospatiale AS350 B2 ECUREUIL, 2 cases](https://openairdocs.org/ntsb-events/900/sequence.md?model=8680813), [All aircraft, 1,556 cases](https://openairdocs.org/ntsb-events/900/sequence.md) ## Analysis The helicopter pilot reported that, during startup on an off-airport landing pad, the helicopter was facing into the wind, and the airspeed indicator was showing gusting wind conditions. As the blades began to turn, he felt a strong wind gust and heard a loud bang almost simultaneously, and the helicopter "lurched" to the right about 5°. He immediately aborted the start procedure and applied the rotor brake. Postaccident examination revealed that the helicopter's main rotor blade had struck the tail rotor driveshaft cover and damaged the tail rotor drive shaft and support assembly. The pilot reported that there were no preaccident mechanical failures or malfunctions with the helicopter that would have precluded normal operation. The pilot reported that the weather at the accident site, about the time of the accident, was wind from 130° at 25 knots, gusting to 30 knots with light, terrain-induced turbulence. The flight manual stated that the wind envelope for spinning and stopping the rotors has been substantiated for winds of 40 knots from any direction and for 50-knot headwinds. ## Factual narrative The helicopter pilot reported that, during startup on an off-airport landing pad, the helicopter was facing into the wind and the airspeed indicator was shoring gusting wind conditions. As the blades began to turn, he felt a strong gust of wind and heard a loud bang almost simultaneously, and the helicopter "lurched" to the right about 5 degrees. He immediately aborted the start procedure and applied the rotor brake. A postaccident examination revealed the helicopter's main rotor blade had struck the tail rotor driveshaft cover and damaged the tail rotor drive shaft and support assembly. The pilot reported that there were no preaccident mechanical failures or malfunctions with the helicopter that would have precluded normal operation. The pilot reported the weather at the accident site, about the time of the accident was, wind from 130° at 25 knots, gusting to 30 knots with light terrain-induced turbulence. The flight manual states that the wind envelope for spinning and stopping the rotors has been substantiated for winds of 40 knots from any direction and for 50 knots headwinds. ## Aircraft - Registration: [N288CH](https://openairdocs.org/aircraft/N288CH), registered now, S/N 2383, built 1990 (OpenAirDocs) - Reported make and model: AEROSPATIALE AS350 B2 ECUREUIL (NO SERIES) - Registry model: [Aerospatiale AS350 B2 ECUREUIL](https://openairdocs.org/model/aerospatiale-as350-b2-ecureuil) (registry code 8680813) (OpenAirDocs) - Registry engine: [Turbomeca ARRIEL-1SER](https://openairdocs.org/engine/turbomeca-arriel-1ser) (registry code 60030, turbo-shaft) (OpenAirDocs) - Category: Helicopter - Serial number: 2383 - Year built: 1990 - Airframe hours: 9854.4 - Engines: TURBOMECA ARRIEL 1D1 531 horsepower turbo shaft - Damage: Substantial damage - Flight: Part 135 - Operator: Coastal Helicopters Inc - Registered owner: Coastal Helicopters Inc - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, February 13, 2018 - Departed: JNU, Juneau, AK - Destination: Yakutat, AK - Flight plan: Company VFR - Equipment: ADS-B, Satellite tracking device ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 45; injuries: none; commercial; airplane ratings: single-engine land, single-engine sea, multi-engine land; instrument ratings: airplane; medical: class 2, without waivers/limitations; last flight review May 9, 2018; seat: right; restraint: 4-point; flight hours: 4,648 total, 701 in this make and model, 4,500 as pilot in command, 55.7 in the last 90 days, 47.7 in the last 30 days, 2.7 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 140° at 14 knots, gusting 28 - Visibility: 10 statute miles - Lowest ceiling: 1,000 ft broken - Temperature: 50 °F, dew point 45 °F - Altimeter: 30.00 inHg - Turbulence: Light - Observed at: PAYA, 52 nm away ## 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 20180518004389A](https://openairdocs.org/incident/20180518004389A), May 18, 2018: Aerospatiale AS350 B2 ECUREUIL, Yakutat, AK, Substantial damage. The part 135 flight departed from juneau on 18MAY2018 at 12:51 AKDT to service a us coast guard radio facility on the 2200' level deception hills located near… ## Other investigations on N288CH (1) 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. - [NTSB GAA19CA233](https://openairdocs.org/ntsb/GAA19CA233), Apr 28, 2019: Aerospatiale AS350 (N288CH), Juneau, AK, substantial damage. Probable cause: The pilot's failure to maintain a proper approach to landing on a ridge and his failure to maintain clearance from snow-covered terrain, which resulted in a tail rotor strike. ## Docket (3 files) The files NTSB released with the investigation on September 6, 2018, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=97290. 1.3 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 871 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40466305&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Accident Pictures (item 2, .PDF, 2 photos, 357 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40466306&FileExtension=.PDF&FileName=Accident%20Pictures-Master.PDF - AS350B2 Section 5 (item 3, .PDF, 119 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40466307&FileExtension=.PDF&FileName=AS350B2%20Section%205-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. --- 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.