# NTSB WPR12LA408: Bell Helicopter Textron 206L-1, N5745Y, Grand Canyon, AZ, September 9, 2012 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: September 9, 2012, 11:52 local (18:52 UTC) - Place: Grand Canyon, AZ - Coordinates: 35.801944, -112.068054 - Nearby events: https://openairdocs.org/map.md?lat=35.8019&lon=-112.0681&mi=10 - Phase of flight: [Emergency descent](https://openairdocs.org/ntsb-phases/600) (OpenAirDocs' grouping) - Defining event: [Autorotation: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report December 14, 2015 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration, Papillon Helicopters, Rolls-Royce, North America - NTSB case key (mKey): 84974 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR12LA408 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/84974/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=84974 - Page: https://openairdocs.org/ntsb/WPR12LA408 ## Probable cause A total loss of engine power during descent for reasons that could not be determined because postaccident engine examinations and testing revealed no evidence of an anomaly that would have precluded normal operation. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Not determined](https://openairdocs.org/ntsb-findings/05000000): Not determined › Not determined · Unknown/Not determined (probable cause); cases with it: [Bell Helicopter Textron 206L-1, 4 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md?model=1182107), [All aircraft, 2,247 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md) - [Terrain: rough terrain](https://openairdocs.org/ntsb-findings/03021015): Environmental issues › Physical environment · Contributed to outcome; cases with it: [Bell Helicopter Textron 206L-1, 1 case](https://openairdocs.org/ntsb-findings/03021015/cases.md?model=1182107), [All aircraft, 442 cases](https://openairdocs.org/ntsb-findings/03021015/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Autorotation: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) (defining event); cases with it: [Bell Helicopter Textron 206L-1, 7 cases](https://openairdocs.org/ntsb-events/341/sequence.md?model=1182107), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md) - [Emergency descent: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Bell Helicopter Textron 206L-1, 6 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=1182107), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) - [Landing-flare/touchdown: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Bell Helicopter Textron 206L-1, 6 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=1182107), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) ## Analysis The pilot reported that, during a maintenance release flight, he entered a simulated autorotation to check the main rotor rpm. When the pilot retarded the throttle, the engine lost power. The pilot subsequently conducted an off-airport landing. During the landing, the main rotor blade struck the tailboom, which then separated from the airframe. During postaccident engine test runs in both the airframe and a test cell, the engine ran normally. Postaccident engine examinations revealed no anomalies that would have precluded normal operation. The reason for the loss of engine power could not be determined. ## Factual narrative On September 9, 2012, at 1152 mountain standard time (MST), a Bell 206L-1, N5745Y, made a forced autorotation following a loss of engine power near Grand Canyon, Arizona. Papillon Grand Canyon Helicopters was operating the helicopter under the provisions of 14 Code of Federal Regulations (CFR) Part 91. The commercial pilot and passenger were not injured. The helicopter sustained substantial damage to the tail boom when it was struck by one of the main rotor blades. The local flight departed Grand Canyon at 1131. Visual meteorological conditions prevailed, and a company flight plan had been filed. The pilot reported that during a maintenance release flight, he attempted to enter a simulated autorotation to check the main rotor rpm. The pilot stated that when he retarded the throttle the engine quit. During the off airport landing, a main rotor blade impacted the tail boom causing it to depart the airframe. The helicopter had just completed a scheduled 100-hour maintenance inspection. Following the event, the aircraft was recovered to Papillon's facility at Grand Canyon Airport. During the examination, the aircraft fuel system was inspected. There was no reported evidence of oil or fuel leakage. The airframe fuel filter was removed with clean fuel noted and what was identified as normal quantity. The aircraft fuel gage showed 300 lbs. During the post accident inspection the torque of all of the fuel lines using a torque wrench was performed. A rigging check was conducted in accordance with the Overhaul & Maintenance manual with no observed deviations. The engine was then motored, and a fuel flow (bucket) check was conducted with what was considered a normal flow rate and pattern from the engine fuel nozzle. The engine was then started, and a 30-minute ground run was conducted in an unloaded configuration (with engine-to-transmission and No. 1 tail rotor driveshaft disconnected). The engine was removed from the airframe and shipped to Aeromaritime in Mesa, Arizona, for further testing. The engine was placed into a test cell, and the engine was run twice with only minor anomalies noted. The cursory inspection of the engine and engine exterior did not reveal any evidence of mechanical failure or anomaly. The engine testing showed all test points to be within new overhaul limits for steady state, transient, governor droop and anti-ice. The engine performance results showed the engine to be approximately four percent below new overhaul engine specifications. The complete engine examination report is attached to the accident docket. The operator noted that the normal operation after maintenance would be to conduct a maintenance release flight as the accident flight was performed. The operator has modified the post maintenance procedures to include the requirement that all flights requiring a throttle manipulation shall be conducted to facilitate the availability of a hard landing surface in the event of a loss of power. ## Aircraft - Registration: [N5745Y](https://openairdocs.org/aircraft/N5745Y), registered now, S/N 45531, built 1980 (OpenAirDocs) - Reported make and model: BELL HELICOPTER TEXTRON 206L-1 - Registry model: [Bell Helicopter Textron 206L-1](https://openairdocs.org/model/bell-helicopter-textron-206l-1) (registry code 1182107) (OpenAirDocs) - Registry engine: [Allison 250 SER 250HP](https://openairdocs.org/engine/allison-250-ser-250hp) (registry code 03002, turbo-shaft) (OpenAirDocs) - Category: Helicopter - Serial number: 45531 - Airframe hours: 26520 - Engines: Rolls-Royce 250C30P 650 horsepower turbo shaft - Damage: Substantial damage - Flight: Flight test, Part 91 - Operator: Papillon Airways Inc - Registered owner: Monarch Enterprises Inc - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, September 8, 2012, 0 hours before - Departed: GCN, Grand Canyon, AZ - Destination: GCN, Grand Canyon, AZ - Flight plan: Company VFR - Airport: GCN, Grand Canyon National Park ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 50; injuries: none; commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: helicopter, airplane; medical: class 2, with waivers/limitations; last flight review April 5, 2012; seat: right; flight hours: 3,460 total, 1,415 in this make and model, 3,323 as pilot in command, 106 in the last 90 days, 19 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 45° at 9 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 75 °F, dew point 32 °F - Altimeter: 30.03 inHg - Observed at: GCN, 10 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 20120909021669A](https://openairdocs.org/incident/20120909021669A), Sep 9, 2012: Bell Helicopter Textron 206L-1, Grand Canyon, AZ, Substantial damage. 9/10/2012:Two asi's were dispatched to gcn to investigate an aircraft accident regarding an operators aircraft that reported an engine flameout while… ## Other investigations on N5745Y (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 ATL82DA027](https://openairdocs.org/ntsb/ATL82DA027), Jan 2, 1982: Bell 206L-1 (N5745Y), Chamblee, GA, substantial damage ## Docket (4 files) The files NTSB released with the investigation on November 12, 2015, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=84974. 2.1 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 814 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40433779&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Statement of Party Representatives to NTSB Investigation - Papillon (item 2, .PDF, 244 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40433780&FileExtension=.PDF&FileName=Statement%20of%20Party%20Representatives%20to%20NTSB%20Investigation%20-%20Papillon-Master.PDF - Statement of Party Representatives to NTSB Investigation - Rolls Royce (item 3, .PDF, 543 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40433781&FileExtension=.PDF&FileName=Statement%20of%20Party%20Representatives%20to%20NTSB%20Investigation%20-%20Rolls%20Royce-Master.PDF - Engine Examination Report (item 4, .PDF, 4 photos, 458 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40433782&FileExtension=.PDF&FileName=Engine%20Examination%20Report-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.