# NTSB GAA17CA218: Bell 206, N206SA, La Verne, CA, April 6, 2017 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: April 6, 2017, 10:35 local (17:35 UTC) - Place: La Verne, CA - Coordinates: 34.091667, -117.781669 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=34.0917&lon=-117.7817&mi=10 - Phase of flight: [Emergency descent](https://openairdocs.org/ntsb-phases/600) (OpenAirDocs' grouping) - Defining event: [Autorotation: Hard landing](https://openairdocs.org/ntsb-events/092) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report October 31, 2017 - Report: Approved by Office Director - NTSB office: General Aviation Accidents - Parties: FAA - NTSB case key (mKey): 94967 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=GAA17CA218 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/94967/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=94967 - Page: https://openairdocs.org/ntsb/GAA17CA218 ## Probable cause The pilot’s early increased application of the collective during a simulated hovering autorotation, which resulted in a loss of rotor rpm and subsequent main rotor blade strike of the tailboom. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Rotorcraft flight control: main rotor control](https://openairdocs.org/ntsb-findings/01046710): Aircraft › Aircraft propeller/rotor · Incorrect use/operation (probable cause); cases with it: [Bell 206B, 2 cases](https://openairdocs.org/ntsb-findings/01046710/cases.md?model=1181511), [All aircraft, 28 cases](https://openairdocs.org/ntsb-findings/01046710/cases.md) - [Use of equip/info: use of equip/system](https://openairdocs.org/ntsb-findings/02063015): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Bell 206B, 5 cases](https://openairdocs.org/ntsb-findings/02063015/cases.md?model=1181511), [All aircraft, 1,391 cases](https://openairdocs.org/ntsb-findings/02063015/cases.md) - [Action: incorrect action sequence](https://openairdocs.org/ntsb-findings/02041020): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Bell 206B, 1 case](https://openairdocs.org/ntsb-findings/02041020/cases.md?model=1181511), [All aircraft, 77 cases](https://openairdocs.org/ntsb-findings/02041020/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Autorotation: Abrupt maneuver](https://openairdocs.org/ntsb-events/270); cases with it: [Bell 206B, 2 cases](https://openairdocs.org/ntsb-events/270/sequence.md?model=1181511), [All aircraft, 346 cases](https://openairdocs.org/ntsb-events/270/sequence.md) - [Autorotation: 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) - [Autorotation: Hard landing](https://openairdocs.org/ntsb-events/092) (defining event); cases with it: [Bell 206B, 28 cases](https://openairdocs.org/ntsb-events/092/sequence.md?model=1181511), [All aircraft, 2,102 cases](https://openairdocs.org/ntsb-events/092/sequence.md) ## Analysis The flight instructor in the helicopter reported that he was providing hovering autorotation training to a private pilot. The flight instructor reported that he rolled off the throttle to initiate the maneuver, and the private pilot "raised the collective too soon which resulted in the aircraft climbing." The rotor inertia decayed, and a main rotor blade struck the tailboom after the helicopter struck the ground. The helicopter sustained substantial damage to the tail rotor drive shaft. The pilot reported that there were no preaccident mechanical malfunctions or failures with the helicopter that would have precluded normal operation. ## Factual narrative The flight instructor in the helicopter reported that he was providing hovering autorotation training to a private pilot. The flight instructor reported that he rolled off the throttle to initiate the maneuver and the private pilot, "raised the collective too soon which resulted in the aircraft climbing." The rotor inertia decayed and a main rotor blade struck the tailboom after the helicopter struck the ground. The helicopter sustained substantial damage to the tail rotor drive shaft. The pilot reported that there were no preaccident mechanical malfunctions or failures with the helicopter that would have precluded normal operation. ## Aircraft - Registration: [N206SA](https://openairdocs.org/aircraft/N206SA), registered now, S/N 1013, built 1973 (OpenAirDocs) - Reported make and model: BELL 206 (B) - Registry model: [Bell 206B](https://openairdocs.org/model/bell-206b) (registry code 1181511) (OpenAirDocs) - Registry engine: [Allison 250-C20 series](https://openairdocs.org/engine/allison-250-c20-series) (registry code 03020, turbo-prop) (OpenAirDocs) - Category: Helicopter - Serial number: 1013 - Year built: 1973 - Airframe hours: 8482.1 - Engines: Rolls Royce 250-C20 400 horsepower turbo shaft - Damage: Substantial damage - Flight: Instructional, Part 91 - Operator: Havasu Heli Flights, LLC - Registered owner: Havasu Heli Flights, LLC - Airworthiness certificate: Standard, Normal - Last inspection: Annual, March 21, 2017 - Departed: POC, La Verne, CA - Destination: POC, La Verne, CA - Airport: POC, Brackett Field - Equipment: Stall warning system ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 58; injuries: none; airline transport, flight instructor; airplane ratings: single-engine land; instrument ratings: helicopter; medical: class 2, with waivers/limitations; last flight review March 3, 2017; seat: left; flight hours: 15,000 total, 1,800 in this make and model, 15,000 as pilot in command, 30 in the last 90 days, 10 in the last 30 days, 2 in the last 24 hours - Pilot; age 48; injuries: none; private; medical: class 2, without waivers/limitations; last flight review March 25, 2017; seat: right; restraint: 4-point; flight hours: 140 total, 15 in this make and model, 75 as pilot in command, 10 in the last 90 days, 10 in the last 30 days, 2 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 250° at 6 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 70 °F, dew point 48 °F - Altimeter: 30.05 inHg - Observed at: KPOC, 1 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 20170406003809A](https://openairdocs.org/incident/20170406003809A), Apr 6, 2017: Bell 206B, La Verne, CA, Substantial damage. During a training flight, while performing a simulated auto-rotation, collective pitch was introduced to early causing the main rotor to lose momentum… ## Docket (2 files) The files NTSB released with the investigation on September 25, 2017, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=94967. 3.5 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 3.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40456601&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Photos (Courtesy of FAA) (item 2, .PDF, 2 photos, 110 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40456602&FileExtension=.PDF&FileName=Photos%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.