# NTSB CEN19LA067: Bell 47G, N3755Z, Belen, NM, January 11, 2019 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: January 11, 2019, 14:40 local (21:40 UTC) - Place: Belen, NM - Coordinates: 34.618888, -106.832778 - Nearby events: https://openairdocs.org/map.md?lat=34.6189&lon=-106.8328&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering-hover: Loss of control in flight](https://openairdocs.org/ntsb-events/240) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report June 29, 2020 - Report: Approved by Office Director - NTSB office: Central Region - Parties: Federal Aviation Administration ABQ FSDO - SAIBs cited in the narratives: [SAIB CE-09-35](https://openairdocs.org/saib/CE-09-35) (OpenAirDocs) - NTSB case key (mKey): 98885 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN19LA067 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/98885/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=98885 - Page: https://openairdocs.org/ntsb/CEN19LA067 ## Probable cause The pilot's failure to maintain adequate main rotor speed while the helicopter was in an out-of-ground effect hover. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Performance/control parameters: prop/rotor parameters](https://openairdocs.org/ntsb-findings/01062052): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Bell 47G-2, 2 cases](https://openairdocs.org/ntsb-findings/01062052/cases.md?model=1181008), [All aircraft, 182 cases](https://openairdocs.org/ntsb-findings/01062052/cases.md) - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Bell 47G-2, 7 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=1181008), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) - [Attention/monitoring: monitoring equip/instruments](https://openairdocs.org/ntsb-findings/02021525): Personnel issues › Psychological · Pilot (probable cause); cases with it: [Bell 47G-2, 1 case](https://openairdocs.org/ntsb-findings/02021525/cases.md?model=1181008), [All aircraft, 142 cases](https://openairdocs.org/ntsb-findings/02021525/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Maneuvering-hover: Loss of control in flight](https://openairdocs.org/ntsb-events/240) (defining event); cases with it: [Bell 47G-2, 5 cases](https://openairdocs.org/ntsb-events/240/sequence.md?model=1181008), [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md) - [Landing-flare/touchdown: Hard landing](https://openairdocs.org/ntsb-events/092); cases with it: [Bell 47G-2, 3 cases](https://openairdocs.org/ntsb-events/092/sequence.md?model=1181008), [All aircraft, 2,102 cases](https://openairdocs.org/ntsb-events/092/sequence.md) ## Analysis The pilot was on a personal flight when he decided to bring the helicopter into an out-of-ground effect hover about 50 ft above the ground. The pilot stated that he "got complacent about maintaining main rotor speed" while in the hover and observed an unsafe main rotor speed. He lowered collective for an immediate landing and engaged the carburetor heat. He attempted to reduce the helicopter's descent rate before impact by increasing the collective control, but the helicopter landed hard on the soft terrain. The main rotor blades subsequently impacted the tailboom and tail rotor. The pilot reported that, after impact, the engine continued to run at about 1,500 rpm. The pilot reported no preimpact mechanical malfunctions or failures with the helicopter that would have precluded normal operation. The pilot postulated that an insufficient main rotor speed had precluded him from making a normal flare and landing. He stated that the engine might have encountered carburetor icing as he maneuvered the helicopter into the out-of-ground effect hover at a decreased engine power setting, which might have contributed to his failure to maintain adequate main rotor speed while hovering. Regardless of if the helicopter had a partial loss of engine power during the out-of-ground effect hover, which the investigation was unable to determine, the pilot should have been able to maintain proper main rotor speed by lowering collective and discontinuing the hover maneuver before the main rotor decreased to an unsafe speed. ## Factual narrative On January 11, 2019, about 1440 mountain standard time, a Bell 47G-2 helicopter, N3755Z, collided with terrain while maneuvering near Belen, New Mexico. The pilot and passenger were not injured, and the helicopter was substantially damaged. The helicopter was owned by the pilot and operated under Title 14 Code of Federal Regulations (CFR) Part 91 as a personal flight without a flight plan. Day visual meteorological conditions prevailed for the local flight that departed Belen Regional Airport (BRG), near Belen, New Mexico, about 1400.The pilot stated that shortly before the accident he had maneuvered the helicopter into an out-of-ground effect hover about 50 ft above the ground. The pilot reported that the carburetor heat was not engaged while he flew the helicopter in the hover. The pilot stated that he "got complacent about maintaining main rotor speed" and subsequently observed an unsafe main rotor speed. The pilot lowered the collective control for an immediate landing and engaged the carburetor heat. He attempted to reduce the helicopter's descent rate before impact by increasing the collective control, but the helicopter landed hard in the soft terrain. The main rotor blades subsequently impacted the tail boom and tail rotor. The pilot reported that after impact the engine continued to run at about 1,500 rpm, and that he secured the engine by turning the fuel valve to OFF. The pilot reported no preimpact mechanical anomalies with the helicopter that would have precluded normal operation. The pilot postulated that an insufficient main rotor speed had precluded him from making a normal flare and landing. The pilot stated that the engine might have encountered carburetor icing as he maneuvered the helicopter into the out-of-ground effect hover at a decreased engine power setting, which, in turn, might have contributed to his failure to maintain adequate main rotor speed while hovering. A postaccident review of available meteorological data established that day visual meteorological conditions prevailed at the accident site. The nearest aviation weather reporting station was located at Belen Regional Airport (BRG), about 3 miles north of the accident site. At 1435, about 5 minutes before the accident, the BRG automated surface observing system reported: wind 310° at 8 knots, 10 miles surface visibility, clear sky, temperature 8°C, dew point 1°C, and an altimeter setting 29.96 inches of mercury. According to a carburetor icing probability chart contained in FAA Special Airworthiness Information Bulletin CE-09-35, entitled "Carburetor Icing Prevention", the recorded temperature and dew point were in the range of susceptibility for the formation of carburetor icing at all engine power settings. ## Aircraft - Registration: [N3755Z](https://openairdocs.org/deregistered/N3755Z-2023-06-28), registration cancelled 2023-06-28, S/N 1698, built 1955 (OpenAirDocs) - Reported make and model: Bell 47G (2) - Registry model: [Bell 47G-2](https://openairdocs.org/model/bell-47g-2) (registry code 1181008) (OpenAirDocs) - Registry engine: [Lycoming VO-435 series](https://openairdocs.org/engine/lycoming-vo-435-series) (registry code 41525, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: 1698 - Year built: 1955 - Airframe hours: 7163.3 - Engines: Lycoming VO-435-A1F 260 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, June 20, 1980 - Departed: BRG, Belen, NM - Destination: BRG, Belen, NM - Equipment: None ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 72; injuries: none; private; airplane ratings: single-engine land, multi-engine land; seat: left; restraint: lap only; flight hours: 9,000 total, 100 in this make and model, 3 in the last 90 days, 3 in the last 30 days, 0 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 310° at 8 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 46 °F, dew point 34 °F - Altimeter: 29.95 inHg - Observed at: BRG, 3 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 20190111007479A](https://openairdocs.org/incident/20190111007479A), Jan 11, 2019: Bell 47G-2, Belen, NM, Substantial damage. On January 11, 2019 a Bell helicopter 47 G-2 (N3755Z) registered to ernie l. brown, departed Belen Regional Airport (brg) in Belen, NM for a local VFR flight.… ## Other investigations on N3755Z (1) 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. - [NTSB CEN13LA086](https://openairdocs.org/ntsb/CEN13LA086), Dec 1, 2012: Bell 47G-2 (N3755Z), Walkerville, MI, substantial damage, 1 fatal. Probable cause: The pilot's failure to maintain altitude while maneuvering, which resulted in a collision with trees. Contributing to the accident was the pilot's decision to fly at a low altitude, which did not… ## Docket (3 files) The files NTSB released with the investigation on February 11, 2019, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=98885. 1.3 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 892 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40470290&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Memorandum of Conversation - Ernest Brown (item 2, .PDF, 80 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40470291&FileExtension=.PDF&FileName=Memorandum%20of%20Conversation%20-%20Ernest%20Brown-Master.PDF - Photos (item 3, .PDF, 2 photos, 371 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40470292&FileExtension=.PDF&FileName=Photos-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.