# NTSB ANC22LA001: Robinson Helicopter R44 II, N555EL, Palmer, AK, October 10, 2021 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 4 · Limited · Final report - Date: October 10, 2021, 13:20 local (21:20 UTC) - Place: Palmer, AK - Coordinates: 61.40406, -148.60457 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=61.4041&lon=-148.6046&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering-low-alt flying: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470) - 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: Alaska Regional Office - Parties: FAA - NTSB case key (mKey): 104098 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC22LA001 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/104098/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=104098 - Page: https://openairdocs.org/ntsb/ANC22LA001 ## Probable cause (aircraft 1) The unmanned aircraft pilot’s failure to yield the right of way to the helicopter. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Attention/monitoring: monitoring other aircraft](https://openairdocs.org/ntsb-findings/02021540): Personnel issues › Psychological · Pilot of other aircraft (probable cause), aircraft 1; cases with it: [Robinson Helicopter R44 II, 4 cases](https://openairdocs.org/ntsb-findings/02021540/cases.md?model=7640122), [All aircraft, 231 cases](https://openairdocs.org/ntsb-findings/02021540/cases.md) - [Attention/monitoring: monitoring other aircraft](https://openairdocs.org/ntsb-findings/02021540): Personnel issues › Psychological · Pilot (probable cause), aircraft 2; cases with it: [All aircraft, 231 cases](https://openairdocs.org/ntsb-findings/02021540/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: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470) (defining event), aircraft 1; cases with it: [Robinson Helicopter R44 II, 95 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=7640122), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis (aircraft 1) The pilot of the helicopter reported that, while conducting an air tour flight he made about a 90° right turn near a scenic area, when he heard a faint “ting” sound. He stated that there was no indication of a mechanical failure or malfunction and the helicopter continued to operate normally, so he continued the flight. After shutdown he noticed damage to one of the main rotor blades and concluded that the helicopter had collided with an uncrewed aerial vehicle (UAV). The helicopter sustained substantial damage to the main rotor blade. The pilot of the unmanned aircraft system (UAS) reported that while flying his UAV near a scenic area a red helicopter suddenly appeared and collided with the UAV. 14 CFR Part 107.37 Operations near aircraft, right of way rules, states in part: (a) Each small unmanned aircraft must yield the right of way to all aircraft, airborne vehicles, and launch and reentry vehicles. Yielding the right of way means that the small unmanned aircraft must give way to the aircraft or vehicle and may not pass over, under, or ahead of it unless well clear. (b) No person may operate a small unmanned aircraft so close to another aircraft as to create a collision hazard. ## Aircraft 1 - Registration: [N555EL](https://openairdocs.org/aircraft/N555EL), registered now, S/N 10665, built 2005 (OpenAirDocs) - Reported make and model: ROBINSON HELICOPTER COMPANY 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-AE1A5](https://openairdocs.org/engine/lycoming-io-540-ae1a5) (registry code 41899, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: 10665 - Year built: 2005 - Airframe hours: 3760.4 - Engines: LYCOMING IO-540-AE1A5 245 horsepower reciprocating - Damage: Substantial damage - Flight: Aerial observation, Part 135 - Operator: Pollux Aviation Ltd - Registered owner: Pollux Aviation Ltd - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, October 6, 2021 - Destination: Same as departure - Flight plan: Company VFR - Equipment: None ## Aircraft 2 - Registration: FA3P4CAK37 (not matched to a registry record) - Reported make and model: DJI AIR IIS - Category: Unknown, unmanned - Serial number: 3YTSJ4T0030A8A - Damage: Destroyed - Flight: Personal, Part 107 - Operator: Charlie Crosby - Registered owner: Charlie Crosby - Airworthiness certificate: None - Destination: Same as departure - Equipment: None ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot, aircraft N555EL; age 29; injuries: none; commercial, flight instructor; instrument ratings: helicopter; medical: class 1, without waivers/limitations; last flight review June 7, 2021; seat: right; restraint: 5-point; flight hours: 1,252 total, 1,020 in this make and model, 1,188 as pilot in command, 106 in the last 90 days, 21 in the last 30 days, 2 in the last 24 hours - Pilot, aircraft 2; age 50; injuries: none; medical: unknown; seat: none ## Weather - Conditions: Visual (VMC), Day - Wind: 70° at 3 knots - Visibility: 7 statute miles - Lowest ceiling: 2,500 ft overcast - Temperature: 39 °F, dew point 37 °F - Altimeter: 29.69 inHg - Observed at: PAAQ, 18 nm away - METAR: PAAQ 100853Z AUTO 07003KT 7SM -RA OVC025 04/03 A2969 RMK AO2 SLP059 P0005 60013 T00440033 400830011 53023 TSNO ## 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 20211010016261A](https://openairdocs.org/incident/20211010016261A), Oct 10, 2021: Robinson Helicopter Company R44 II, Palmer, AK, Substantial damage. See UAS report atqa #AAL0322003 for additional details. On October 10, 2021 at approximately 1310 AKDT, [privacy data omitted], a Robinson R-44 ii helicopter… ## Docket (3 files) The files NTSB released with the investigation on July 21, 2022, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=104098. 2.0 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 9 pages, 1.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13606427&FileExtension=pdf&FileName=6120_Redacted-Rel.pdf - Witness statements (item 2, PDF, 3 pages, 177 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14194481&FileExtension=pdf&FileName=Witness%20Statements-Rel.pdf - Photos (item 3, PDF, 3 pages, 344 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14171873&FileExtension=pdf&FileName=Photo%20Array%20-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.