# NTSB ANC15CA012: Bell 206B, N86TA, Palmer, AK, March 10, 2015 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: March 10, 2015, 15:00 local (23:00 UTC) - Place: Palmer, AK - Coordinates: 61.409999, -148.546951 - Nearby events: https://openairdocs.org/map.md?lat=61.4100&lon=-148.5470&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: 1 uninjured - Status: Completed, report July 8, 2015 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - Parties: FAA - NTSB case key (mKey): 90851 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC15CA012 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/90851/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=90851 - Page: https://openairdocs.org/ntsb/ANC15CA012 ## Probable cause The pilot's failure to maintain control while hovering at a low altitude, which resulted in an impact with frozen lake ice. Contributing to the accident was the pilot's decision to operate the helicopter from the left seat contrary to the rotorcraft flight manual, and the decision to continue the flight after the initial impact. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Performance/control parameters](https://openairdocs.org/ntsb-findings/01062000): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Bell 206B, 10 cases](https://openairdocs.org/ntsb-findings/01062000/cases.md?model=1181511), [All aircraft, 1,269 cases](https://openairdocs.org/ntsb-findings/01062000/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 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) - [Info processing/decision: decision making/judgment](https://openairdocs.org/ntsb-findings/02041520): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Bell 206B, 13 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md?model=1181511), [All aircraft, 3,098 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md) - [Knowledge: knowledge of procedures](https://openairdocs.org/ntsb-findings/02032010): Personnel issues › Experience/knowledge · Pilot (probable cause); cases with it: [Bell 206B, 1 case](https://openairdocs.org/ntsb-findings/02032010/cases.md?model=1181511), [All aircraft, 41 cases](https://openairdocs.org/ntsb-findings/02032010/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 206B, 32 cases](https://openairdocs.org/ntsb-events/240/sequence.md?model=1181511), [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md) - [Uncontrolled descent: 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) - [Enroute: Fuel exhaustion](https://openairdocs.org/ntsb-events/192); cases with it: [Bell 206B, 8 cases](https://openairdocs.org/ntsb-events/192/sequence.md?model=1181511), [All aircraft, 804 cases](https://openairdocs.org/ntsb-events/192/sequence.md) - [Enroute: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Bell 206B, 21 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=1181511), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) ## Analysis The solo helicopter pilot was flying a turbine-powered helicopter, equipped with dual controls, while seated in the left seat. A limitation in the rotorcraft flight manual states, in part: "the minimum flight crew consists of one pilot who shall operate the helicopter from the right crew seat." The N2 governor linear actuator control switch is located on the collective control for the right crew seat only. The pilot reported that flying the helicopter from the left seat and in order to manipulate this control switch, he had to take his left hand off the collective control for the left crew seat, and place it on the left crew seat cyclic control, then take his right hand off the left crew seat cyclic control and place it on the collective control for the right crew seat. The pilot said that while in a 6-foot hover above a frozen lake, he became distracted while adjusting the N2 (rotor) rpm using the linear actuator control switch, and the helicopter became unstable and it began to rapidly descend. He attempted to recover from the unstable condition, but the helicopter's skids struck the ice. After the impact, he was able to recover and regain a stable hover above the ice. Believing that just the helicopter's skids were damaged during the impact, the pilot elected to return to his departure airport, about 19 miles away, where emergency services would be available. During the return flight, as the helicopter climbed to about 50 feet above the ground, all engine power was lost. The pilot entered an emergency autorotation and selected an area of snow-cover as an emergency landing site. The pilot's postaccident inspection of the helicopter revealed that during the initial impact on the frozen lake, the aft landing gear cross-tube assembly had been crushed into the aft portion of the fuselage, which subsequently ruptured the fuel cell, resulting in the loss of all fuel onboard. The pilot stated there were no preaccident mechanical malfunctions or anomalies that would have precluded normal operation. ## Factual narrative The solo helicopter pilot was flying a turbine-powered helicopter, equipped with dual controls, while seated in the left seat. A limitation in the rotorcraft flight manual states, in part: "the minimum flight crew consists of one pilot who shall operate the helicopter from the right crew seat." The N2 governor linear actuator control switch is located on the collective control for the right crew seat only. The pilot reported that flying the helicopter from the left seat and in order to manipulate this control switch, he had to take his left hand off the collective control for the left crew seat, and place it on the left crew seat cyclic control, then take his right hand off the left crew seat cyclic control and place it on the collective control for the right crew seat. The pilot said that while in a 6-foot hover above a frozen lake, he became distracted while adjusting the N2 (rotor) rpm using the linear actuator control switch, and the helicopter became unstable and it began to rapidly descend. He attempted to recover from the unstable condition, but the helicopter's skids struck the ice. After the impact, he was able to recover and regain a stable hover above the ice. Believing that just the helicopter's skids were damaged during the impact, the pilot elected to return to his departure airport, about 19 miles away, where emergency services would be available. During the return flight, as the helicopter climbed to about 50 feet above the ground, all engine power was lost. The pilot entered an emergency autorotation and selected an area of snow-cover as an emergency landing site. The pilot's postaccident inspection of the helicopter revealed that during the initial impact on the frozen lake, the aft landing gear cross-tube assembly had been crushed into the aft portion of the fuselage, which subsequently ruptured the fuel cell, resulting in the loss of all fuel onboard. The pilot stated there were no preaccident mechanical malfunctions or anomalies that would have precluded normal operation. ## Aircraft - Registration: [N86TA](https://openairdocs.org/deregistered/N86TA-2019-08-15), registration cancelled 2019-08-15, S/N 1647, built 1975 (OpenAirDocs) - Reported make and model: BELL 206B (B) - Registry model: [Bell 206B](https://openairdocs.org/model/bell-206b) (registry code 1181511) (OpenAirDocs) - Registry engine: [Allison 250 SER 400HP](https://openairdocs.org/engine/allison-250-ser-400hp) (registry code 03013, turbo-shaft) (OpenAirDocs) - Category: Helicopter - Serial number: 1647 - Year built: 1975 - Airframe hours: 8367 - Engines: ALLISON 250-C20B 420 horsepower turbo shaft - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Lee John S - Registered owner: Lee John S - Airworthiness certificate: Standard, Normal - Last inspection: Annual, November 14, 2014 - Departed: PAAQ, Palmer, AK - Destination: PAAQ, Palmer, AK - Flight plan: VFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 69; injuries: none; airline transport, flight instructor; airplane ratings: single-engine land, single-engine sea, multi-engine land; instrument ratings: helicopter; medical: class 3, waiver time limited special; last flight review September 22, 2014; seat: left; restraint: 4-point; flight hours: 14,190 total, 1,200 in this make and model, 12,000 as pilot in command, 50 in the last 90 days, 15 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 160° at 4 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 16 °F, dew point -4 °F - Altimeter: 30.14 inHg - Observed at: PAAQ, 19 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 20150310003009A](https://openairdocs.org/incident/20150310003009A), Mar 10, 2015: Bell 206B, Palmer, AK, Substantial damage. Pilot was in a hover over the knik glacier. Pilot was flying by himself from left seat. Pilot lost track of rotor RPM while concentrating on correcting N2, and… ## Other investigations on N86TA (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 ANC98LA003](https://openairdocs.org/ntsb/ANC98LA003), Oct 15, 1997: Bell 206-B2 (N86TA), Sutton, AK, substantial damage. Probable cause: The pilot's failure to maintain clearance between the tail rotor and the external long line cable, and the subsequent entanglement of the tail rotor with the long line. ## Docket (2 files) The files NTSB released with the investigation on June 24, 2015, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=90851. 968 KB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 914 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428280&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Memorandum for Record - Telephone Interview, Pilot (item 2, .PDF, 53 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428281&FileExtension=.PDF&FileName=Memorandum%20for%20Record%20-%20Telephone%20Interview,%20Pilot-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.