# NTSB GAA17CA495: Bell 206, N6259C, Minden, NV, August 20, 2017 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: August 20, 2017, 12:30 local (19:30 UTC) - Place: Minden, NV - Coordinates: 38.998332, -119.757225 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=38.9983&lon=-119.7572&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing: Loss of tail rotor effectiveness](https://openairdocs.org/ntsb-events/242) - Highest injury: No injuries - Injuries: 5 uninjured - Status: Completed, report November 27, 2017 - Report: Approved by Office Director - NTSB office: General Aviation Accidents - Parties: FAA - NTSB case key (mKey): 95841 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=GAA17CA495 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/95841/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=95841 - Page: https://openairdocs.org/ntsb/GAA17CA495 ## Probable cause The pilot’s failure to maintain helicopter control during landing due to a loss of tail rotor effectiveness. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Bell 206B, 45 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=1181511), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) - [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 206B, 11 cases](https://openairdocs.org/ntsb-findings/01062052/cases.md?model=1181511), [All aircraft, 182 cases](https://openairdocs.org/ntsb-findings/01062052/cases.md) - [Object/animal/substance: fence/fence post](https://openairdocs.org/ntsb-findings/03022047): Environmental issues › Physical environment · Contributed to outcome; cases with it: [Bell 206B, 1 case](https://openairdocs.org/ntsb-findings/03022047/cases.md?model=1181511), [All aircraft, 313 cases](https://openairdocs.org/ntsb-findings/03022047/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Landing: Loss of tail rotor effectiveness](https://openairdocs.org/ntsb-events/242) (defining event); cases with it: [Bell 206B, 13 cases](https://openairdocs.org/ntsb-events/242/sequence.md?model=1181511), [All aircraft, 100 cases](https://openairdocs.org/ntsb-events/242/sequence.md) - [Landing: Attempted remediation/recovery](https://openairdocs.org/ntsb-events/060); cases with it: [Bell 206B, 14 cases](https://openairdocs.org/ntsb-events/060/sequence.md?model=1181511), [All aircraft, 1,422 cases](https://openairdocs.org/ntsb-events/060/sequence.md) - [Landing: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Bell 206B, 57 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=1181511), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The pilot of the helicopter reported that, during landing, the helicopter "encountered LTE [loss of tail rotor effectiveness]." He added that he maneuvered the helicopter to an open field adjacent to the intended helipad and that the tail rotor impacted a barbed wire fence. The helicopter sustained substantial damage to the empennage. The pilot reported that there were no preaccident mechanical failures or malfunctions with the helicopter that would have precluded normal operation. The Federal Aviation Administration's Helicopter Flying Handbook, FAA-H-8083-21A, contained a section titled "Loss of Tail Rotor Effectiveness (LTE)," which stated: Loss of tail rotor effectiveness (LTE) or an unanticipated yaw is defined as an uncommanded, rapid yaw towards the advancing blade which does not subside of its own accord. It can result in the loss of the aircraft if left unchecked. It is very important for pilots to understand that LTE is caused by an aerodynamic interaction between the main rotor and tail rotor and not caused from a mechanical failure. Some helicopter types are more likely to encounter LTE due to the normal certification thrust produced by having a tail rotor that, although meeting certification standards, is not always able to produce the additional thrust demanded by the pilot. ## Factual narrative The pilot of the helicopter reported that, during landing, the helicopter "encountered LTE [loss of tail rotor effectiveness]". He added that he maneuvered the helicopter to an open field adjacent to the intended helipad and the tail rotor impacted a barbed wire fence. The helicopter sustained substantial damage to the empennage. The pilot reported that there were no preaccident mechanical failures or malfunctions with the helicopter that would have precluded normal operation. Federal Aviation Administration's Helicopter Flying Handbook, FAA-H-8083-21A, contains a section titled "Loss of Tail Rotor Effectiveness (LTE)" which states: Loss of tail rotor effectiveness (LTE) or an unanticipated yaw is defined as an uncommanded, rapid yaw towards the advancing blade which does not subside of its own accord. It can result in the loss of the aircraft if left unchecked. It is very important for pilots to understand that LTE is caused by an aerodynamic interaction between the main rotor and tail rotor and not caused from a mechanical failure. Some helicopter types are more likely to encounter LTE due to the normal certification thrust produced by having a tail rotor that, although meeting certification standards, is not always able to produce the additional thrust demanded by the pilot. ## Aircraft - Registration: [N6259C](https://openairdocs.org/aircraft/N6259C), registered now, S/N 703 (OpenAirDocs) - Reported make and model: BELL 206 (B) - Registry model: [Bell 206B](https://openairdocs.org/model/bell-206b) (registry code 1181511) (OpenAirDocs) - Category: Helicopter - Serial number: 703 - Year built: 1971 - Airframe hours: 22237.4 - Engines: Rolls Royce 250-C20B 320 horsepower turbo shaft - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Helicopter Parts International Inc - Registered owner: Helicopter Parts International Inc - Airworthiness certificate: Standard, Normal - Last inspection: Annual, May 11, 2017 - Destination: MEV, Minden, NV - Airport: MEV, Minden-Tahoe - Equipment: None ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 63; injuries: none; private; airplane ratings: single-engine land; medical: class 3, without waivers/limitations; last flight review May 13, 2017; seat: right; restraint: 4-point; flight hours: 664 total, 562 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: variable at 3 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 77 °F, dew point 45 °F - Altimeter: 30.17 inHg - Observed at: KMEV ## 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 20170820010439A](https://openairdocs.org/incident/20170820010439A), Aug 20, 2017: Bell 206B, Minden, NV, Substantial damage. During an approach for landing at an off airport helipad, the pilot stated "while landing at helipad, helicopter encountered lte (loss of tail rotor… ## Docket (2 files) The files NTSB released with the investigation on October 31, 2017, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=95841. 975 KB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 854 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40457531&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Accidents Photos (Courtesy of FAA) (item 2, .PDF, 2 photos, 120 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40457532&FileExtension=.PDF&FileName=Accidents%20Photos%20(Courtesy%20of%20FAA)-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.