# NTSB ANC20CA068: Robinson R44, N878CB, Ketchikan, AK, July 10, 2020 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 4 · Data collection · Final report - Date: July 10, 2020, 10:30 local (18:30 UTC) - Place: Ketchikan, AK - Coordinates: 55.766944, -131.41694 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=55.7669&lon=-131.4169&mi=10 - Phase of flight: [Standing](https://openairdocs.org/ntsb-phases/150) (OpenAirDocs' grouping) - Defining event: [Standing-engine(s) operating: Miscellaneous/other](https://openairdocs.org/ntsb-events/900) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 4 - Basic report with no Prelim publish - NTSB office: Alaska Regional Office - Parties: FAA - NTSB case key (mKey): 101605 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC20CA068 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/101605/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=101605 - Page: https://openairdocs.org/ntsb/ANC20CA068 ## Probable cause The crew leader's decision to throw a chainsaw bar into the moving arc of the main rotor blade. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Info processing/decision: decision making/judgment](https://openairdocs.org/ntsb-findings/02041520): Personnel issues › Action/decision · Ground crew (probable cause); cases with it: [Robinson Helicopter R44 II, 40 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md?model=7640122), [All aircraft, 3,098 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md) - [Object/animal/substance: ground equipment](https://openairdocs.org/ntsb-findings/03022050): Environmental issues › Physical environment · Effect on equipment (probable cause); cases with it: [Robinson Helicopter R44 II, 3 cases](https://openairdocs.org/ntsb-findings/03022050/cases.md?model=7640122), [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. - [Standing-engine(s) operating: Miscellaneous/other](https://openairdocs.org/ntsb-events/900) (defining event); cases with it: [Robinson Helicopter R44 II, 19 cases](https://openairdocs.org/ntsb-events/900/sequence.md?model=7640122), [All aircraft, 1,556 cases](https://openairdocs.org/ntsb-events/900/sequence.md) ## Analysis The pilot reported that, after landing on an elevated helicopter deck and reducing the rotor RPM, he signaled for the brush cutting ground crew leader to approach the helicopter to collect additional chainsaw bars that were being dropped off. He added that, the crew leader indicated that two of the three chainsaw bars were not the correct bars needed, and then threw an incorrect bar away from the helicopter. Subsequently, the bar impacted a main rotor blade, which resulted in substantial damage. The pilot reported that the brush cutting crew had been briefed before operations on gear security, rotor awareness, and safe practices when working around the helicopter. The crew leader admitted to a lapse in judgment brought on by stress and frustration. The pilot reported that there were no preaccident mechanical failures or malfunctions with the helicopter that would have precluded normal operation. ## Factual narrative The pilot reported that, after landing on an elevated helicopter deck and reducing the rotor RPM, he signaled for the brush cutting ground crew leader to approach the helicopter to collect additional chainsaw bars that were being dropped off. He added that, the crew leader indicated that two of the three chainsaw bars were not the correct bars needed, and then threw an incorrect bar away from the helicopter. Subsequently, the bar impacted a main rotor blade, which resulted in substantial damage. The pilot reported that the brush cutting crew had been briefed before operations on gear security, rotor awareness, and safe practices when working around the helicopter. The crew leader admitted to a lapse in judgment brought on by stress and frustration. The pilot reported that there were no preaccident mechanical failures or malfunctions with the helicopter that would have precluded normal operation. ## Aircraft - Registration: [N878CB](https://openairdocs.org/aircraft/N878CB), registered now, S/N 10404, built 2004 (OpenAirDocs) - Reported make and model: Robinson R44 (II) - Registry model: [Robinson Helicopter R44 II](https://openairdocs.org/model/robinson-helicopter-r44-ii) (registry code 7640122) (OpenAirDocs) - Registry engine: [Lycoming IO-540 series](https://openairdocs.org/engine/lycoming-io-540-series) (registry code 41530, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: 10404 - Year built: 2004 - Airframe hours: 3323 - Engines: Lycoming IO-540 AE1A5 245 horsepower reciprocating - Damage: Substantial damage - Flight: Part 135 - Operator: Helicopter Air Alaska, LLC - Registered owner: Helicopter Air Alaska, LLC - Airworthiness certificate: Standard, Normal - Last inspection: Annual, May 20, 2020 - Departed: Neets Bay, AK - Destination: Ketchikan, AK - Flight plan: Company VFR - Equipment: Handheld GPS, ADS-B, Satellite tracking device ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 30; injuries: none; commercial, flight instructor; instrument ratings: helicopter; medical: class 2, without waivers/limitations; last flight review June 12, 2020; seat: right; restraint: 5-point; flight hours: 1,533 total, 660 in this make and model, 1,472 as pilot in command, 95 in the last 90 days, 33 in the last 30 days, 5 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 140° at 13 knots - Visibility: 5 statute miles - Lowest ceiling: 2,300 ft overcast - Temperature: 55 °F, dew point 54 °F - Altimeter: 29.84 inHg - Observed at: PAKT, 26 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). - [Incident 20200710004789I](https://openairdocs.org/incident/20200710004789I), Jul 10, 2020: Robinson Helicopter Company R44 II, Neets Bay, AK, Minor damage. The operator was conducting flights at a remote location in Neets Bay, Alaska which is located approximately 29 miles north of ketchikan. The flights occurred… ## Other investigations on N878CB (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 ANC21LA079](https://openairdocs.org/ntsb/ANC21LA079), Aug 30, 2021: Robinson Helicopter R44 II (N878CB), Pelican, AK, substantial damage. Probable cause: The pilot’s improper preflight planning to ensure adequate power to hover out-of-ground effect while conducting external load operations. ## Docket (2 files) The files NTSB released with the investigation on August 3, 2021, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=101605. 879 KB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 9 pages, 235 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=9999169&FileExtension=pdf&FileName=6120_Redacted-Rel.pdf - Accident pictures (item 2, PDF, 2 pages, 644 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=9997951&FileExtension=pdf&FileName=Accident%20Pictures-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.