# NTSB GAA17CA132: Bell Helicopter Textron 206, N519EH, Carson City, NV, February 2, 2017 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Data collection · Final report - Date: February 1, 2017, 16:30 local (Feb 2, 2017, 00:30 UTC) - Place: Carson City, NV - Coordinates: 39.192222, -119.732498 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=39.1922&lon=-119.7325&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing-flare/touchdown: Dynamic rollover](https://openairdocs.org/ntsb-events/231) - Highest injury: Minor injuries - Injuries: 2 minor - Status: Completed, report September 7, 2017 - Report: Approved by Office Director - NTSB office: General Aviation Accidents - Parties: FAA - NTSB case key (mKey): 94695 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=GAA17CA132 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/94695/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=94695 - Page: https://openairdocs.org/ntsb/GAA17CA132 ## Probable cause The pilot-in-command’s delayed remedial action to arrest the right yaw after the bounced landing while operating in a flight regime conducive to the loss of tail rotor effectiveness, which resulted in a roll-over. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Action: delayed action](https://openairdocs.org/ntsb-findings/02041025): Personnel issues › Action/decision · Instructor/check pilot (probable cause); cases with it: [Bell Helicopter Textron 206L-1, 3 cases](https://openairdocs.org/ntsb-findings/02041025/cases.md?model=1182107), [All aircraft, 894 cases](https://openairdocs.org/ntsb-findings/02041025/cases.md) - [Performance/control parameters: yaw control](https://openairdocs.org/ntsb-findings/01062024): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Bell Helicopter Textron 206L-1, 3 cases](https://openairdocs.org/ntsb-findings/01062024/cases.md?model=1182107), [All aircraft, 149 cases](https://openairdocs.org/ntsb-findings/01062024/cases.md) - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Instructor/check pilot (probable cause); cases with it: [Bell Helicopter Textron 206L-1, 8 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=1182107), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Landing-flare/touchdown: Abnormal runway contact](https://openairdocs.org/ntsb-events/090); cases with it: [Bell Helicopter Textron 206L-1, 2 cases](https://openairdocs.org/ntsb-events/090/sequence.md?model=1182107), [All aircraft, 1,506 cases](https://openairdocs.org/ntsb-events/090/sequence.md) - [Landing-flare/touchdown: Dynamic rollover](https://openairdocs.org/ntsb-events/231) (defining event); cases with it: [Bell Helicopter Textron 206L-1, 3 cases](https://openairdocs.org/ntsb-events/231/sequence.md?model=1182107), [All aircraft, 161 cases](https://openairdocs.org/ntsb-events/231/sequence.md) ## Analysis The flight instructor on the controls of the high skid-equipped-landing-gear helicopter reported that he was the pilot-in-command (PIC). The PIC reported that he and another flight instructor were performing simulated emergency procedures during the flight. He reported that he attempted to demonstrate a simulated fixed-pitch (right stuck antitorque pedal) emergency procedure. He reported that, during the maneuver, the nose of the helicopter was about 40° nose right of centerline. He reduced the throttle, and the nose corrected to about 20° nose right of centerline. The helicopter touched down on taxiway delta with minimal forward airspeed, and it then bounced about 5 ft above the ground and yawed right about 1 3/4 turns. The helicopter touched down a second time about 65 ft south of the taxiway centerline and rolled onto its left side. The helicopter sustained substantial damage to the firewall, main rotor drive system, and tail rotor drive system. A METAR at the time of the accident reported that the wind was from 110° at 08 kts. The flight instructor seated in the right seat reported that the wind at the time of the accident was from 090° at 08 kts. When the PIC was asked by the National Transportation Safety Board investigator-in-charge if he placed the collective in the full-down position after touchdown or if he increased the collective after the initial touchdown, he responded that he could not remember. When asked if he applied full left pedal to combat the right yaw, he said that he did not because the event happened quickly. According to the Federal Aviation Administration Helicopter Flying Handbook (FAA-8083-21A), the Helicopter Instructor's Flying Handbook (FAA-8083-4), and Advisory Circular (AC) 90-95 "Unanticipated Rapid Right Yaw in Helicopters," the loss of tail rotor effectiveness is a critical, low-speed aerodynamic flight characteristic that can result in an uncommanded rapid yaw rate that does not subside of its own accord and, if not corrected, can result in the loss of aircraft control. AC 90-95, Section 7.d.3. (page 7), defines flight characteristics and wind azimuths and states that the tail rotor vortex ring state occurs when the wind is from 210° to 330°. 1. Winds within this region will result in the development of the vortex ring state of the tail rotor. AC 90-95, Section 10, "Recommended Recovery Techniques," (page 8), states: a. If a sudden unanticipated right yaw occurs, the pilot should perform the following: (1) Apply full left pedal. Simultaneously, move cyclic forward to increase speed. If altitude permits, reduce power. (2) As recovery is effected, adjust controls for normal forward flight. b. Collective pitch reduction will aid in arresting the yaw rate but may cause an increase in the rate of descent. Any large, rapid increase in collective to prevent ground or obstacle contact may further increase the yaw rate and decrease rotor rpm. The pilot reported that there were no preaccident mechanical malfunctionsor failures with the helicopter that would have precluded normal operation. ## Factual narrative The flight instructor on the controls of the high skid-equipped landing gear helicopter reported that he was the pilot in command (PIC). The PIC reported that he and another flight instructor were performing simulated emergency procedures during the flight. He reported that he attempted to demonstrate a simulated fixed pitch (right stuck anti-torque pedal) emergency procedure. He reported that during the maneuver the nose of the helicopter was about 40° nose right of centerline. He reduced the throttle and the nose corrected to about 20° nose right of centerline. The helicopter touched down on taxiway delta with minimal forward airspeed, and the aircraft bounced about 5 ft above the ground and yawed right about 1 ¾ turns. The helicopter touched down a second time about 65 ft south of the taxiway centerline and rolled onto its left side. The helicopter sustained substantial damage to the firewall, main rotor drive system and tail rotor drive system. The Meteorological Aerodrome Report for the airport which the accident occurred and at the time the accident occurred, identified that the wind was out of the 110° at 08 kts. The flight instructor seated in the right seat, reported that the wind at the time of the accident was out of 090° at 08 kts. When the PIC was asked by the NTSB investigator-in-charge (IIC); was the collective placed in the full down position after touchdown, he could not remember. When asked if he increased the collective after the initial helicopter touchdown; he could not remember. When asked if he applied full left pedal to combat the right yaw, he said that he did not because the event happened quickly. According to the Federal Aviation Administration Helicopter Flying Handbook (FAA-8083-21A) and The Helicopter Instructors Flying Handbook (FAA-8083-4) and Advisory Circular (AC) 90-95 Unanticipated rapid right yaw; Loss of Tail Rotor Effectiveness (LTE) is a critical; low-speed aerodynamic flight characteristic which can result in an uncommanded rapid yaw rate which does not subside of its own accord and, if not corrected, can result in the loss of aircraft control. AC 90-95 Section 7. d. 3. (page 7) defines Flight Characteristics and wind azimuths: Tail rotor vortex ring state occurs when the wind is out of (210° to 330°). 1. Winds within this region will result in the development of the vortex ring state of the tail rotor. AC 90-95, Section 10. a. 1-2 (page 8) is titled Recommended Recovery Techniques and states: a. If a sudden unanticipated right yaw occurs, the pilot should perform the following: (1) Apply full left pedal. Simultaneously, move cyclic forward to increase speed. If altitude permits, reduce power. (2) As recovery is effected, adjust controls for normal forward flight. b. Collective pitch reduction will aid in arresting the yaw rate but may cause an increase in the rate of descent. Any large, rapid increase in collective to prevent ground or obstacle contact may further increase the yaw rate and decreaserotor rpm. The pilot reported that there were no preaccident mechanical malfunctions or failures with the helicopter that would have precluded normal operation. ## Aircraft - Registration: [N519EH](https://openairdocs.org/deregistered/N519EH-2018-09-13), registration cancelled 2018-09-13, S/N 45429, built 1980 (OpenAirDocs) - Reported make and model: BELL HELICOPTER TEXTRON 206 (L1) - Registry model: [Bell Helicopter Textron 206L-1](https://openairdocs.org/model/bell-helicopter-textron-206l-1) (registry code 1182107) (OpenAirDocs) - Registry engine: [Allison 250-C30 series](https://openairdocs.org/engine/allison-250-c30-series) (registry code 03015, turbo-shaft) (OpenAirDocs) - Category: Helicopter - Serial number: 45429 - Year built: 1980 - Airframe hours: 15844.7 - Engines: Rolls Royce 250-C30P 650 horsepower turbo shaft - Damage: Substantial damage - Flight: Instructional, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, January 24, 2017 - Departed: CXP, Carson City, NV - Destination: CXP, Carson City, NV - Airport: CXP, Carson, runway 09, 6,101 × 75 ft, asphalt - Equipment: Satellite tracking device ## Flight crew As NTSB recorded them. NTSB leaves out names. - Flight instructor; age 46; injuries: minor; flight instructor, commercial; instrument ratings: helicopter; medical: class 2, without waivers/limitations; last flight review January 16, 2016; seat: left; restraint: 4-point; flight hours: 3,300 total, 6 in this make and model, 3,146 as pilot in command, 26 in the last 90 days, 6 in the last 30 days, 2 in the last 24 hours - Flight instructor; age 62; injuries: minor; airline transport, flight instructor; instrument ratings: helicopter; medical: class 2, with waivers/limitations; last flight review September 1, 2016; seat: right; restraint: 4-point; flight hours: 7,954 total, 4 in this make and model, 7,274 as pilot in command, 39 in the last 90 days, 6 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 90° at 8 knots - Visibility: 10 statute miles - Temperature: 46 °F, dew point 28 °F - Altimeter: 29.98 inHg - Observed at: CXP ## 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 20170201001959A](https://openairdocs.org/incident/20170201001959A), Feb 1, 2017: Bell Helicopter Textron 206L-1, Carson City, NV, Substantial damage. The accident flight began at 1610PST conducting left hand traffic on runway 9 at cxp. The crew conducted two straight in autorotation?s without incident. The… ## Other investigations on N519EH (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 SEA00LA020](https://openairdocs.org/ntsb/SEA00LA020), Nov 17, 1999: Bell 206L-1 (N519EH), Neihart, MT, substantial damage. Probable cause: Clearance from an object was not maintained. Gusting wind conditions was a factor. ## Docket (3 files) The files NTSB released with the investigation on August 17, 2017, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=94695. 4.8 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 4.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40455388&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Memorandum for Record - Pilot (item 2, .PDF, 140 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40455389&FileExtension=.PDF&FileName=Memorandum%20for%20Record%20-%20Pilot-Master.PDF - Photo (Courtesy of FAA) (item 3, .PDF, 1 photo, 128 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40455390&FileExtension=.PDF&FileName=Photo%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.