# NTSB CEN23LA086: Robinson Helicopter R44, N811S, Fowlerton, TX, January 10, 2023 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Class 4 · Limited · Final report - Date: January 10, 2023, 12:40, time zone not recorded - Place: Fowlerton, TX · ranch land with trees - Coordinates: 28.255431, -98.739375 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=28.2554&lon=-98.7394&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: Flight Standards District Office - NTSB case key (mKey): 106607 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN23LA086 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/106607/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=106607 - Page: https://openairdocs.org/ntsb/CEN23LA086 ## Probable cause The pilot’s failure to maintain clearance with trees, which resulted in an uncontrollable spin due to tail rotor damage. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Object/animal/substance: tree(s)](https://openairdocs.org/ntsb-findings/03022020): Environmental issues › Physical environment · Contributed to outcome (probable cause); cases with it: [Robinson Helicopter R44, 4 cases](https://openairdocs.org/ntsb-findings/03022020/cases.md?model=7640120), [All aircraft, 933 cases](https://openairdocs.org/ntsb-findings/03022020/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) - [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) ## 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 reported that the flight’s purpose was to guide cattle while at low altitude. During a turn with trees in the vicinity, the pilot heard a noise and felt a bump in the flight controls. The helicopter began to spin uncontrollably and impacted terrain, which resulted in substantial damage to the main rotor system, tail rotor system, fuselage, and tail boom. Examination revealed that the tail rotor gear box and tail rotor (TR) blades were separated from the helicopter. The gear box housing fracture surfaces were consistent with overload. The size/shape of the dents and tree debris lodged in the leading edge of the TR blades was consistent with the size/shape of the tree branches that were broken. The pilot reported that there were no preaccident mechanical malfunctions or failures that would have precluded normal operation. ## Aircraft - Registration: [N811S](https://openairdocs.org/aircraft/N811S), registered now, S/N 30072, built 2020 (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 series](https://openairdocs.org/engine/lycoming-o-540-series) (registry code 42713, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: 30072 - Year built: 2020 - Airframe hours: 691 - Engines: Lycoming 0540F-1B5 210 hp reciprocating - Damage: Substantial damage - Flight: Aerial observation, Part 91 - Operator: Smith Helicopters Inc - Registered owner: Smith Helicopters Inc - Airworthiness certificate: Standard, Normal - Last inspection: Annual, October 28, 2022 - Departed: PRI, Cotulla, TX - Destination: PRI, Cotulla, TX ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 67; injuries: minor; commercial; medical: class 2, with waivers/limitations; last flight review August 14, 2021; seat: front; restraint: 3-point; flight hours: 36,920 total, 3,500 in this make and model, 128 in the last 90 days ## Weather - Conditions: Visual (VMC), Day - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 75 °F, dew point 59 °F - Altimeter: 30.06 inHg - Observed at: KCOT, 28 nm away - METAR: KCOT 101853Z AUTO VRB05KT 10SM CLR 24/15 A3006 RMK AO2 SLP172 T0239015 ## 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 20230110000379A](https://openairdocs.org/incident/20230110000379A), Jan 10, 2023: Robinson Helicopter R44, Fowlerton, TX, Substantial damage. Pilot was herding cattle. One steer attempted to break from herd. Pilot turned helicopter to cut off warward steer. Heard a bang and lost tailrotor authority… ## Docket (3 files) The files NTSB released with the investigation on March 23, 2023, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=106607. 2.7 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 11 pages, 2.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15131233&FileExtension=pdf&FileName=6120%20--_Redacted-Rel.pdf - Photos (item 2, PDF, 3 pages, 545 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15132895&FileExtension=pdf&FileName=Photos-Rel.pdf - Examination correspondence (item 3, PDF, 1 page, 132 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15164646&FileExtension=pdf&FileName=Examination%20Correspondence-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.