# NTSB CEN23LA130: Robinson Helicopter R44, N4164T, De Kalb, TX, March 11, 2023 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Class 3 · Limited · Final report - Date: March 11, 2023, 15:30 local (21:30 UTC) - Place: De Kalb, TX · field - Coordinates: 33.658, -94.6375 - Nearby events: https://openairdocs.org/map.md?lat=33.6580&lon=-94.6375&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering-low-alt flying: Loss of control in flight](https://openairdocs.org/ntsb-events/240) - Highest injury: Serious injuries - Injuries: 1 serious, 1 minor, 2 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Central Region - Parties: FAA Flight Standards - NTSB case key (mKey): 106877 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN23LA130 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/106877/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=106877 - Page: https://openairdocs.org/ntsb/CEN23LA130 ## Probable cause The pilot’s inability to maintain control of the helicopter due to his failure to maintain rotor speed. Contributing to the accident was the failure of the helicopter’s low rotor speed warning system. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Use of equip/info: use of equip/system](https://openairdocs.org/ntsb-findings/02063015): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Robinson Helicopter R44, 4 cases](https://openairdocs.org/ntsb-findings/02063015/cases.md?model=7640120), [All aircraft, 1,391 cases](https://openairdocs.org/ntsb-findings/02063015/cases.md) - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Robinson Helicopter R44, 40 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=7640120), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) - [Indicating/recording systems: central warning](https://openairdocs.org/ntsb-findings/01023150): Aircraft › Aircraft systems · Inoperative (probable cause); cases with it: [Robinson Helicopter R44, 1 case](https://openairdocs.org/ntsb-findings/01023150/cases.md?model=7640120), [All aircraft, 9 cases](https://openairdocs.org/ntsb-findings/01023150/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: Loss of control in flight](https://openairdocs.org/ntsb-events/240) (defining event); cases with it: [Robinson Helicopter R44, 43 cases](https://openairdocs.org/ntsb-events/240/sequence.md?model=7640120), [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md) - [Maneuvering-low-alt flying: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330); cases with it: [Robinson Helicopter R44, 7 cases](https://openairdocs.org/ntsb-events/330/sequence.md?model=7640120), [All aircraft, 994 cases](https://openairdocs.org/ntsb-events/330/sequence.md) - [Emergency descent: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Robinson Helicopter R44, 56 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=7640120), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The flight was conducted to hunt feral hogs. The pilot reported that a group of hogs had entered a large field, and he lowered the collective to maneuver the helicopter closer. When he lowered the collective, he perceived a loss of engine and rotor speed. The helicopter immediately began to lose lift. Once the pilot realized that he could not recover the helicopter, he attempted a running (skid-on) landing. However, the landing skids got stuck in the muddy field, the helicopter rocked forward, and the main rotor blades struck the ground causing the aircraft to roll over. The pilot reported the low rotor speed warning did not activate when the rotor speed started to decay. He also stated that all required preflight checklists were complied with before the flight began and no anomalies were noted. A postrecovery examination was unremarkable with exception of the low rotor warning system, which was not operational at the time of the examination. Specifically, the warning system did not activate when the collective control was brought off the low pitch stop and increased to full travel. The reason for the failure of the low rotor warning system was not determined. ## Factual narrative On March 11, 2023, about 1530 central standard time, a Robinson Helicopter R-44, N4164T, was substantially damaged when it was involved in an accident near De Kalb, Texas. The pilot and one passenger were not injured, a second passenger sustained minor injuries, and a third passenger was seriously injured. The helicopter was operated as a Title 14 Code of Federal Regulations Part 91 aerial observation flight. The flight was conducted to hunt feral hogs. The pilot reported that a group of hogs had entered a large field, and he lowered the collective to maneuver the helicopter closer. When he lowered the collective, he perceived a loss of engine and rotor speed. The helicopter immediately began to lose lift. Once the pilot realized that he could not recover the helicopter, he attempted a running (skid-on) landing. However, the landing skids got stuck in the muddy field, the helicopter rocked forward, and the main rotor blades struck the ground causing the aircraft to roll over. The pilot reported the low rotor speed warning did not activate when the rotor speed started to decay. He also stated that all required preflight checklists were complied with before the flight began and no anomalies were noted. The helicopter sustained damage to the fuselage, main rotor blades, and tail boom. The aft portion of the tail boom, with the tail rotor assembly attached, was separated from the remainder of the airframe. It was located adjacent to the fuselage at the accident site. Postrecovery airframe and engine examinations, which included an 8-minute engine run, did not reveal any evidence of an in-flight structural failure, a flight control malfunction, or an inability of the engine to produce rated power. Although, the separated portion of the tail boom and tail rotor assembly were present at the accident site, they were not with the wreckage when recovered. The postrecovery examinations were unremarkable with exception of the low rotor warning system, which was not operational at the time of the examination. Specifically, the warning system did not activate when the collective control was brought off the low pitch stop and increased to full travel. The low rotor warning indicator bulb illuminated, and the warning horn emitted an audible sound when electrical current was applied. The reason for the failure of the low rotor warning system was not determined. ## Aircraft - Registration: [N4164T](https://openairdocs.org/deregistered/N4164T-2025-06-05), registration cancelled 2025-06-05, S/N 1882, 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: 1882 - Year built: 2008 - Airframe hours: 2065.3 - Engines: Lycoming O-540-F1B5 260 horsepower reciprocating - Damage: Substantial damage - Flight: Aerial observation, Part 91 - Operator: Hotel Sierra Aviation LLC, doing business as N/A - Registered owner: Hotel Sierra Aviation LLC - Airworthiness certificate: Standard, Normal - Last inspection: Annual, December 10, 2022, 16.9 hours before - Departed: PVT, Haworth, OK - Destination: PVT, Haworth, OK - Airport: N/A, N/A - Equipment: ADS-B ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 38; injuries: none; private; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, without waivers/limitations; last flight review November 2, 2022; seat: rear; restraint: 3-point; flight hours: 1,972 total, 355 in this make and model, 1,750 as pilot in command, 135 in the last 90 days, 70 in the last 30 days, 10 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 190° at 8 knots - Visibility: 9 statute miles - Lowest ceiling: 2,700 ft broken - Temperature: 72 °F, dew point 63 °F - Altimeter: 29.62 inHg - Observed at: KTXK, 31 nm away - METAR: METAR KTXK 112153Z 19008KT 9SM SCT020 BKN027 OVC036 22/17 A2962 ## Docket (10 files) The files NTSB released with the investigation on January 2, 2025, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=106877. 96.6 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 10 pages, 4.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=17971974&FileExtension=pdf&FileName=Accident%20Report%20--%20CEN23LA130_redacted-Rel.pdf - Pilot statement (item 2, PDF, 1 page, 68 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=17979459&FileExtension=pdf&FileName=ROC%20--%20Lawrence_22May2023-Rel.pdf - Passenger statements (item 3, PDF, 3 pages, 1.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=17971746&FileExtension=pdf&FileName=Passenger%20Stmts%20--%20CEN23LA130_Redacted-Rel.pdf - Witness statement (pilot of 2nd helicopter) (item 4, PDF, 1 page, 2.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=17972389&FileExtension=pdf&FileName=Witness%20Statement%20(Pilot%20of%202nd%20Helicopter)%20--%20CEN23LA130_redacted-Rel.pdf - Investigation photos (item 5, PDF, 9 pages, 2.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=17978797&FileExtension=pdf&FileName=Investigation%20Photos%20--%20CEN23LA130-Rel.pdf - Helicopter examination summary (item 6, PDF, 6 pages, 142 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=17979310&FileExtension=pdf&FileName=Examination%20Summary%20--%20CEN23FA130-Rel.pdf - Recovery operator statement (item 7, PDF, 1 page, 67 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=17972882&FileExtension=pdf&FileName=ROC%20--%20WeldonGarrison_03May2023-Rel.pdf - Maintenance records -- airframe (item 8, PDF, 20 pages, 43.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=17979851&FileExtension=pdf&FileName=Maintenance%20Records%20--%20Airframe_redacted-Rel.pdf - Maintenance records -- engine (item 9, PDF, 16 pages, 42.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=17979544&FileExtension=pdf&FileName=Maintenance%20Records%20--%20Engine_redacted-Rel.pdf - Statement of party representatives to NTSB investigation (item 10, PDF, 2 pages, 986 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=17973400&FileExtension=pdf&FileName=Party%20Statements%20--%20CEN23LA130_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.