# NTSB GAA19CA531: Robinson R44, N447PA, Nuiqsut, AK, September 6, 2019 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: September 6, 2019, 13:50 local (21:50 UTC) - Place: Nuiqsut, AK - Coordinates: 63.88861, -160.799163 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=63.8886&lon=-160.7992&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing: Prop/jet/rotor blast/suction](https://openairdocs.org/ntsb-events/082) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report March 17, 2020 - Report: Approved by Office Director - NTSB office: General Aviation Accidents - NTSB case key (mKey): 100220 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=GAA19CA531 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/100220/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=100220 - Page: https://openairdocs.org/ntsb/GAA19CA531 ## Probable cause The pilot's improper decision to land downwind from unsecured debris, which resulted in the helicopter’s main rotor disk ingesting foreign objects. ## 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 · Pilot (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: debris/dirt/foreign object](https://openairdocs.org/ntsb-findings/03022055): Environmental issues › Physical environment · Effect on operation (probable cause); cases with it: [Robinson Helicopter R44 II, 3 cases](https://openairdocs.org/ntsb-findings/03022055/cases.md?model=7640122), [All aircraft, 101 cases](https://openairdocs.org/ntsb-findings/03022055/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Landing: Prop/jet/rotor blast/suction](https://openairdocs.org/ntsb-events/082) (defining event); cases with it: [Robinson Helicopter R44 II, 1 case](https://openairdocs.org/ntsb-events/082/sequence.md?model=7640122), [All aircraft, 44 cases](https://openairdocs.org/ntsb-events/082/sequence.md) ## Analysis The pilot reported that he landed the helicopter facing south and about 90 ft from where ground personnel were unhooking super sacks filled with gravel. When the skids touched down, the pilot reduced the collective and then saw an empty super sack about 15 ft away, which subsequently struck the main rotor toward the outboard portion of the blade. The super sack was ingested by the advancing side of the main rotor disk. The pilot rolled off the throttle and shut down the engine. The helicopter sustained substantial damage to the main rotor blades. The pilot reported that there were no preaccident mechanical failures or malfunctions with the helicopter that would have precluded normal operation. ## Factual narrative The helicopter pilot reported that, he landed the helicopter facing south and about 30 yards from the empty gravel carrying super sacks. When the skids touched down, the pilot reduced the collective and saw a super sack about 15ft away and coming at the helicopter. The super sack was ingested by the advancing side of the main rotor disk. The pilot rolled off throttle and shut down the engine. The helicopter sustained substantial damage to the main rotor blades. The pilot reported that the wind at the accident site was from the southwest about 15 knots. The pilot reported that there were no preaccident mechanical failures or malfunctions with the helicopter that would have precluded normal operation. ## Aircraft - Registration: [N447PA](https://openairdocs.org/aircraft/N447PA), registered now, S/N 11197, built 2006 (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-AE1A5](https://openairdocs.org/engine/lycoming-io-540-ae1a5) (registry code 41899, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: 11197 - Year built: 2006 - Airframe hours: 4038.8 - Engines: Lycoming IO-540-AE1A5 260 horsepower reciprocating - Damage: Substantial damage - Flight: External load, Part 133 - Operator: Pollux Aviation Ltd - Registered owner: Pollux Aviation Ltd - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, August 30, 2019 - Departed: PASC, Deadhorse, AK - Destination: PASC, Deadhorse, AK - Airport: AQT, Nuiqsut - Equipment: Handheld GPS ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 32; injuries: none; flight instructor, commercial; instrument ratings: helicopter; medical: class 2, without waivers/limitations; last flight review May 14, 2019; seat: right; restraint: 5-point; flight hours: 2,215 total, 1,780 in this make and model, 2,149 as pilot in command, 102 in the last 90 days, 68 in the last 30 days, 5 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 220° at 7 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 90 °F, dew point 43 °F - Altimeter: 30.09 inHg - Observed at: PAUN ## 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 20190906017129I](https://openairdocs.org/incident/20190906017129I), Sep 6, 2019: Robinson Helicopter Company R44 II, Nuiqsut, AK, Minor damage. After landing at field site drill pad, pilot offloaded passengers to refuel. While performing cool down prior to engine shutdown and subsequent fueling, gusty… ## Docket (2 files) The files NTSB released with the investigation on January 3, 2020, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=100220. 3.9 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 3.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40479576&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Photo (item 2, .PDF, 174 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40479577&FileExtension=.PDF&FileName=Photo-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.