# NTSB ANC17CA041: Airbus AS350, N351SH, Delta Junction, AK, August 3, 2017 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: August 3, 2017, 13:00 local (22:00 UTC) - Place: Delta Junction, AK - Coordinates: 64.467781, -144.914993 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=64.4678&lon=-144.9150&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing: Collision during takeoff/land](https://openairdocs.org/ntsb-events/490) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report September 22, 2017 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - Parties: Safran Helicopter Engines (Technical Advisor), FAA Fairbanks FSDO, Bureau d’Enquêtes et d’Analyses, Airbus Helicopters (Technical Advisor) - NTSB case key (mKey): 95765 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC17CA041 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/95765/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=95765 - Page: https://openairdocs.org/ntsb/ANC17CA041 ## Probable cause The pilot’s failure to maintain clearance from a steel frame attached to a tracked drilling unit. Contributing to the accident was the pilot’s failure to visually identify the steel frame during the reconnaissance process. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Attention/monitoring: monitoring environment](https://openairdocs.org/ntsb-findings/02021545): Personnel issues › Psychological · Pilot (probable cause); cases with it: [Eurocopter AS 350 B3, 4 cases](https://openairdocs.org/ntsb-findings/02021545/cases.md?model=8680954), [All aircraft, 809 cases](https://openairdocs.org/ntsb-findings/02021545/cases.md) - [Object/animal/substance: ground equipment](https://openairdocs.org/ntsb-findings/03022050): Environmental issues › Physical environment · Effect on operation (probable cause); cases with it: [Eurocopter AS 350 B3, 3 cases](https://openairdocs.org/ntsb-findings/03022050/cases.md?model=8680954), [All aircraft, 52 cases](https://openairdocs.org/ntsb-findings/03022050/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Landing: Miscellaneous/other](https://openairdocs.org/ntsb-events/900); cases with it: [Eurocopter AS 350 B3, 6 cases](https://openairdocs.org/ntsb-events/900/sequence.md?model=8680954), [All aircraft, 1,556 cases](https://openairdocs.org/ntsb-events/900/sequence.md) - [Landing: Collision during takeoff/land](https://openairdocs.org/ntsb-events/490) (defining event); cases with it: [Eurocopter AS 350 B3, 1 case](https://openairdocs.org/ntsb-events/490/sequence.md?model=8680954), [All aircraft, 1,309 cases](https://openairdocs.org/ntsb-events/490/sequence.md) - [Landing: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Eurocopter AS 350 B3, 10 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=8680954), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The helicopter pilot reported that he was transporting a passenger to a remote drilling site where a tracked drilling unit was stationed. He reported that he landed into the wind, which necessitated descending over bordering trees into the drilling site. The helicopter touched down on the dirt, and upon lowering the collective, he reported that he heard a "bang," and the helicopter slowly started to "pick up a ground wobble." The pilot shut down the helicopter, and both occupants exited without further incident. A postaccident inspection revealed that the blue and red main rotor blades sustained substantial damage from impacting a black 1.5-inch steel frame attached to the tracked drilling unit, which is used to mount a canvas weather shelter for the drilling crews. The pilot reported that the steel frame was not visible to him from above as he was descending into the drilling site. The pilot further reported that he had made multiple landings at the drilling site in the past 3 months and that, with the previous landings, he had landed farther past the tracked drilling unit, and the steel frame was always behind the helicopter. The pilot reported that there were no preimpact mechanical failures or malfunctions with the airframe or engine that would have precluded normal operation. The Federal Aviation Administration Helicopter Flying Handbook (FAA-H-8083-21A, 2012) discusses high and low reconnaissance procedures and states, in part: The purpose of conducting a high reconnaissance is to determine direction and speed of the wind, a touchdown point, suitability of the landing area, approach and departure axes, and obstacles for both the approach and departure. A low reconnaissance is accomplished during the approach to the landing area. When flying the approach, verify what was observed in the high reconnaissance, and check for anything new that may have been missed at a higher altitude, such as wires and their supporting structures (poles, towers, etc.), slopes, and small crevices. ## Factual narrative The helicopter pilot reported that he was transporting a passenger to a remote drilling site, where a tracked drilling unit was stationed. He reported that he landed into the wind, which necessitated descending over bordering trees into the drilling site. The helicopter touched down on the dirt, and upon lowering the collective, he reported he heard a "bang" and the helicopter slowly started to "pick up a ground wobble." The pilot shutdown the helicopter and both occupants exited without further incident. A postaccident inspection revealed that the blue and red main rotor blades sustained substantial damage from impacting a black 1.5-inch steel frame attached to the tracked drilling unit, which is used to mount a canvas weather shelter for the drilling crews. The pilot reported that the steel frame was not visible to him from above as he was descending into the drilling site. The pilot further reported that multiple landings have been made to the drilling site in the past 3 months, and that with the previous landings he landed further past the tracked drilling unit and the steel frame was always behind the helicopter. The pilot reported that there were no preimpact mechanical failures or malfunctions with the airframe or engine that would have precluded normal operation. The Federal Aviation Administration Helicopter Flying Handbook (FAA-H-8083-21A, 2012) discusses high and low reconnaissance procedures and states in part: The purpose of conducting a high reconnaissance is to determine direction and speed of the wind, a touchdown point, suitability of the landing area, approach and departure axes, and obstacles for both the approach and departure. A low reconnaissance is accomplished during the approach to the landing area. When flying the approach, verify what was observed in the high reconnaissance, and check for anything new that may have been missed at a higher altitude, such as wires and their supporting structures (poles, towers, etc.), slopes, and small crevices. ## Aircraft - Registration: [N351SH](https://openairdocs.org/deregistered/N351SH-2021-08-24), registration cancelled 2021-08-24, S/N 4598, built 2008 (OpenAirDocs) - Reported make and model: AIRBUS AS350 (B3) - Registry model: [Eurocopter AS 350 B3](https://openairdocs.org/model/eurocopter-as-350-b3) (registry code 8680954) (OpenAirDocs) - Registry engine: [Turbomeca ARRIEL-2B1](https://openairdocs.org/engine/turbomeca-arriel-2b1) (registry code 60056, turbo-shaft) (OpenAirDocs) - Category: Helicopter - Serial number: 4598 - Year built: 2008 - Airframe hours: 3823.7 - Engines: Safran Helicopter Engines Arriel 2B1 847 horsepower turbo shaft - Damage: Substantial damage - Flight: Part 135 - Operator: Soloy Helicopters, LLC, doing business as Soloy Helicopters, LLC - Registered owner: Wells Fargo Bank Northwest Na Trustee - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, June 19, 2017 - Departed: 76AK, DELTA JUNCTION, AK - Destination: 76AK, DELTA JUNCTION, AK - Flight plan: Company VFR - Equipment: None ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 64; injuries: none; commercial; medical: class 2, with waivers/limitations; last flight review May 12, 2017; seat: right; restraint: 4-point; flight hours: 14,998 total, 2,300 in this make and model, 14,800 as pilot in command, 340 in the last 90 days, 167 in the last 30 days, 5 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 180° at 13 knots - Visibility: 10 statute miles - Lowest ceiling: 11,000 ft broken - Temperature: 72 °F, dew point 46 °F - Altimeter: 30.12 inHg - Observed at: PABI, 35 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 20170803012769A](https://openairdocs.org/incident/20170803012769A), Aug 3, 2017: Eurocopter AS 350 B3, Big Delta, AK, Substantial damage. Pilot landed too close to a piece of equipment. Rotor blades struck steel rail on the equipment. ## Other investigations on N351SH (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 WPR21FA143](https://openairdocs.org/ntsb/WPR21FA143), Mar 28, 2021: Airbus Helicopters AS350-B3 (N351SH), Palmer, AK, substantial damage, 5 fatal. Probable cause: The pilot’s failure to adequately respond to an encounter with whiteout conditions, which resulted in the helicopter’s collision with terrain. Contributing to the accident was the (1) operator’s… ## Docket (2 files) The files NTSB released with the investigation on August 31, 2017, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=95765. 1.2 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 672 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40455810&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Photos (Courtesy of Operator) (item 2, .PDF, 4 photos, 487 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40455811&FileExtension=.PDF&FileName=Photos%20(Courtesy%20of%20Operator)-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.