# NTSB CEN21LA350: Robinson Helicopter R44, N775AK, Waukon, IA, August 4, 2021 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Class 4 · Limited · Final report - Date: August 4, 2021, 08:15 local (13:15 UTC) - Place: Waukon, IA - Coordinates: 43.261185, -91.375664 - Nearby events: https://openairdocs.org/map.md?lat=43.2612&lon=-91.3757&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering-low-alt flying: Low altitude operation/event](https://openairdocs.org/ntsb-events/220) - Highest injury: Minor injuries - Injuries: 1 minor - Status: Completed - Report: Approved by Office Director - Investigation class: Class 4 - Basic report with no Prelim publish - NTSB office: Central Region - Parties: FAA Flight Standards - NTSB case key (mKey): 103624 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN21LA350 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/103624/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=103624 - Page: https://openairdocs.org/ntsb/CEN21LA350 ## Probable cause The pilot’s failure to maintain adequate clearance from a powerline during an agricultural application pass. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Object/animal/substance: wire](https://openairdocs.org/ntsb-findings/03022032): Environmental issues › Physical environment · Awareness of condition (probable cause); cases with it: [Robinson Helicopter R44, 18 cases](https://openairdocs.org/ntsb-findings/03022032/cases.md?model=7640120), [All aircraft, 588 cases](https://openairdocs.org/ntsb-findings/03022032/cases.md) - [Performance/control parameters: altitude](https://openairdocs.org/ntsb-findings/01062012): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Robinson Helicopter R44, 22 cases](https://openairdocs.org/ntsb-findings/01062012/cases.md?model=7640120), [All aircraft, 1,310 cases](https://openairdocs.org/ntsb-findings/01062012/cases.md) - [Attention/monitoring: monitoring environment](https://openairdocs.org/ntsb-findings/02021545): Personnel issues › Psychological · Pilot (probable cause); cases with it: [Robinson Helicopter R44, 21 cases](https://openairdocs.org/ntsb-findings/02021545/cases.md?model=7640120), [All aircraft, 809 cases](https://openairdocs.org/ntsb-findings/02021545/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: Low altitude operation/event](https://openairdocs.org/ntsb-events/220) (defining event); cases with it: [Robinson Helicopter R44, 26 cases](https://openairdocs.org/ntsb-events/220/sequence.md?model=7640120), [All aircraft, 780 cases](https://openairdocs.org/ntsb-events/220/sequence.md) ## Analysis The pilot was conducting an agricultural application pass when the helicopter struck a powerline crossing the cornfield being sprayed. He did not see the line until exiting the helicopter after the accident. Earlier in the morning he had surveyed the area for obstacles but did not observe any lines crossing the field. The pilot commented that his initial survey pass was completed toward the east with the sun “low in the sky and in [his] eyes.” He noted that there were no issues with the helicopter before contacting with the power line. The helicopter sustained substantial damage to the main rotor system, the fuselage, and the empennage. ## Aircraft - Registration: [N775AK](https://openairdocs.org/deregistered/N775AK-2022-12-03), registration cancelled 2022-12-03, S/N 1875, built 2008 (OpenAirDocs) - Reported make and model: ROBINSON HELICOPTER R44 - Registry model: [Robinson Helicopter R44](https://openairdocs.org/model/robinson-helicopter-r44) (registry code 7640120) (OpenAirDocs) - Registry engine: [Lycoming O-540-F1B5](https://openairdocs.org/engine/lycoming-o-540-f1b5) (registry code 42353, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: 1875 - Year built: 2008 - Airframe hours: 1973.5 - Engines: Lycoming O-540-F1B5 260 horsepower reciprocating - Damage: Substantial damage - Flight: Aerial application, Part 137 - Operator: Rotors LLC - Registered owner: Rotors LLC - Airworthiness certificate: Special, Restricted (Special) - Last inspection: Annual, March 10, 2021, 187.9 hours before - Equipment: Unknown ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 66; injuries: minor; commercial; airplane ratings: single-engine sea, single-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review March 15, 2021; seat: right; restraint: 3-point; flight hours: 27,652 total, 3,015 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: 0 knots - Visibility: 7 statute miles - Lowest ceiling: none - Temperature: 61 °F, dew point 61 °F - Altimeter: 30.14 inHg - Observed at: DEH, 16 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 20210804012999A](https://openairdocs.org/incident/20210804012999A), Aug 4, 2021: Robinson Helicopter R44, Waukon, IA, Substantial damage. Pilot hit electrical wires. Crashed in field close to the road ## Docket (5 files) The files NTSB released with the investigation on October 5, 2021, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=103624. 28.0 MB in all. - Pilot statement (item 1, PDF, 4 pages, 2.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12736896&FileExtension=pdf&FileName=Pilot%20Stmt%20--%20CEN21LA350-Rel.pdf - Conversation summary -- pilot (item 2, PDF, 1 page, 155 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12744588&FileExtension=pdf&FileName=ROC%20--%20Kurt%20Lepping%20--%2005Aug2021-Rel.pdf - Witness statements (item 3, PDF, 4 pages, 2.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12736585&FileExtension=pdf&FileName=Witness%20Stmts%20--%20CEN21LA350_redacted-Rel.pdf - Sheriff's office photos (excerpts) (item 4, PDF, 15 pages, 8.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12737157&FileExtension=pdf&FileName=Accident%20Photos_Excerpts%20(Sheriff%27s%20Office)%20--%20CEN21LA350-Rel.pdf - Maintenance records (item 5, PDF, 6 pages, 14.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12737224&FileExtension=pdf&FileName=Maintenance%20Records%20--%20N775AK_redacted-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.