# NTSB CEN12LA235: Eurocopter SA315B, N929JV, Alva, OK, March 30, 2012 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: March 30, 2012, 09:43 local (14:43 UTC) - Place: Alva, OK - Coordinates: 36.792974, -98.66531 - Nearby events: https://openairdocs.org/map.md?lat=36.7930&lon=-98.6653&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute: Uncontained engine failure](https://openairdocs.org/ntsb-events/343) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report January 31, 2013 - Report: Approved by Office Director - NTSB office: Central Region - Parties: FAA Flight Standards District Office - NTSB case key (mKey): 83335 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN12LA235 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/83335/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=83335 - Page: https://openairdocs.org/ntsb/CEN12LA235 ## Probable cause Failure of the current and previous operators to comply with the manufacturer's maintenance procedures for operation in sandy environments, which resulted in turbine case erosion and the subsequent uncontained engine failure. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Action: lack of action](https://openairdocs.org/ntsb-findings/02041030): Personnel issues › Action/decision · Maintenance personnel (probable cause); cases with it: [Eurocopter SA315B, 1 case](https://openairdocs.org/ntsb-findings/02041030/cases.md?model=8680993), [All aircraft, 792 cases](https://openairdocs.org/ntsb-findings/02041030/cases.md) - [Engine (turbine/turboprop): turbine section](https://openairdocs.org/ntsb-findings/01057250): Aircraft › Aircraft power plant · Failure (probable cause); cases with it: [Eurocopter SA315B, 1 case](https://openairdocs.org/ntsb-findings/01057250/cases.md?model=8680993), [All aircraft, 74 cases](https://openairdocs.org/ntsb-findings/01057250/cases.md) - [Oversight: oversight of maintenance](https://openairdocs.org/ntsb-findings/04032020): Organizational issues › Support/oversight/monitoring · Operator (probable cause); cases with it: [Eurocopter SA315B, 1 case](https://openairdocs.org/ntsb-findings/04032020/cases.md?model=8680993), [All aircraft, 28 cases](https://openairdocs.org/ntsb-findings/04032020/cases.md) - [Oversight: oversight of reg compliance](https://openairdocs.org/ntsb-findings/04032040): Organizational issues › Support/oversight/monitoring · Operator (probable cause); cases with it: [Eurocopter SA315B, 1 case](https://openairdocs.org/ntsb-findings/04032040/cases.md?model=8680993), [All aircraft, 14 cases](https://openairdocs.org/ntsb-findings/04032040/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Enroute: Uncontained engine failure](https://openairdocs.org/ntsb-events/343) (defining event); cases with it: [Eurocopter SA315B, 1 case](https://openairdocs.org/ntsb-events/343/sequence.md?model=8680993), [All aircraft, 47 cases](https://openairdocs.org/ntsb-events/343/sequence.md) - [Autorotation: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Eurocopter SA315B, 1 case](https://openairdocs.org/ntsb-events/440/sequence.md?model=8680993), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) ## Analysis The helicopter was flying at 300 feet above the ground with an external load when the pilot heard a loud noise from the engine and the rotor rpm began to decay. He jettisoned the load and entered an autorotation. During the flare, the helicopter's main rotor blades contacted the tail rotor drive shaft. Engine disassembly and examination revealed that the turbine casing was deeply eroded by particles that had accumulated in the casing as a result of operating in dusty environments. The erosion caused a crack to develop, and non-uniform overheating of the engine led to the partial melting of the nozzle guide vanes and the rupture of the blade tips in all three turbine stages. Uncontained debris then punctured the turbine casing and shroud. According to the helicopter's maintenance records, the helicopter had operated 68 hours past a 100-hour inspection. The erosion in the engine was likely preexisting since it had been purchased second hand. Further, the records contained no entries pertaining to compliance with the manufacturer's maintenance procedures, by either the current or previous owner, for operations in sandy environments. The current operator reported that they have since complied with the manufacturer’s procedures. ## Factual narrative On March 30, 2012, about 0943 central daylight time, the pilot of a Eurocopter SA315B, N929JV, made a forced landing in an open field about 25 miles northwest of Alva, Oklahoma, after the engine lost power. The pilot, the sole occupant on board, was not injured. The helicopter was substantially damaged. The helicopter was registered to Roberts Aircraft Company, Cheyenne, Wyoming, and operated by Trans Aero, Ltd., of Longmont, Colorado, under the provisions of 14 Code of Federal Regulations (Part 133 as an external load operation. Visual meteorological conditions prevailed at the time of the accident, and no flight plan had been filed. The local flight originated from Alva, Oklahoma, about 0830. According to the pilot's statement, he was flying at 300 feet above the ground with an external load. He heard a loud noise from the engine and the rotor rpm began to decay. He jettisoned the load and entered an autorotation. During the flare, the helicopter's main rotor blades contacted the tail rotor drive shaft. The helicopter tilted up on its nose then settled back on its skids. The engine was removed from the airframe and shipped to Turbomeca in Tarnos, France, where it was disassembled and examined under the oversight of the Bureau d’Enquêtes et d’Analyses (BEA), the French aircraft accident investigation bureau. According to Turbomeca's report, which was endorsed by BEA, the turbine casing was deeply eroded by particles that had accumulated in the casing as a result of operating in dusty environments. The erosion caused a crack to develop, and non-uniform overheating of the engine led to the partial melting of the nozzle guide vanes and the rupture of the blade tips in all three turbine stages. Uncontained debris then punctured the turbine casing and shroud. Turbomeca Procedure 72-40-01, page 203, describes how sand deposits were to be eliminated. There was nothing in the helicopter's engine maintenance records to indicate that this procedure had been performed. ## Aircraft - Registration: [N929JV](https://openairdocs.org/deregistered/N929JV-2014-08-08), registration cancelled 2014-08-08, S/N 2361, built 1973 (OpenAirDocs) - Reported make and model: Eurocopter SA315B - Registry model: [Eurocopter SA315B](https://openairdocs.org/model/eurocopter-sa315b) (registry code 8680993) (OpenAirDocs) - Registry engine: [Turbomeca ARTOUSTEIIIB](https://openairdocs.org/engine/turbomeca-artousteiiib) (registry code 60003, turbo-shaft) (OpenAirDocs) - Category: Helicopter - Serial number: 2361 - Airframe hours: 12160 - Engines: Turbomeca Artouste IIIB 858 horsepower turbo shaft - Damage: Substantial damage - Flight: External load, Part 133 - Operator: Trans Aero, Ltd., doing business as Trans Aero Helicopters, Ltd - Registered owner: Roberts Aircraft Company - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, March 23, 2012, 164 hours before - Departed: KAVK, Alva, OK - Destination: KAVK, Alva, OK - Flight plan: Unknown ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 63; injuries: none; commercial; airplane ratings: multi-engine land, single-engine sea, single-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review April 1, 2011; seat: right; flight hours: 18,500 total, 3,500 in this make and model, 17,500 as pilot in command, 161 in the last 90 days, 52 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 210° at 2 knots - Visibility: 7 statute miles - Lowest ceiling: none ## 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 20120330005509A](https://openairdocs.org/incident/20120330005509A), Mar 30, 2012: Eurocopter SA315B, Alva, OK, Substantial damage. Pilot was enroute at 300-400' AGL, 1500' MSL, with an external load when the engine quit at N37 03.19, W099 00.59, 0930 CDT, 30 mar 2012. Pilot entered… ## Docket (5 files) The files NTSB released with the investigation on December 3, 2012, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=83335. 5.6 MB in all. - NTSB Form 6120, Pilot-Operator Aircraft Accident Report (item 1, .PDF, 1.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40366709&FileExtension=.PDF&FileName=NTSB%20Form%206120,%20Pilot-Operator%20Aircraft%20Accident%20Report-Redacted.PDF - BEA, Technical Document, Engine Examination (item 2, .PDF, 148 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40380116&FileExtension=.PDF&FileName=BEA,%20Technical%20Document,%20Engine%20Examination-Master.PDF - Photo 1 - Left front of helicopter. Main rotor blades have been removed to effect retrieval. (item 3, .PDF, 1.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40380118&FileExtension=.PDF&FileName=Photo%201%20-%20Left%20front%20of%20helicopter.%20Main%20rotor%20blades%20have%20been%20removed%20to%20effect%20retrieval.-Master.PDF - Photo 2 - Right side of helicopter. Tail rotor drive shaft is bent and some hangers are damaged. (item 4, .PDF, 1.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40380119&FileExtension=.PDF&FileName=Photo%202%20-%20Right%20side%20of%20helicopter.%20Tail%20rotor%20drive%20shaft%20is%20bent%20and%20some%20hangers%20are%20damaged.-Master.PDF - Photo 3 - Left side of helicopter and engine with hole in turbine case. (item 5, .PDF, 1.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40380120&FileExtension=.PDF&FileName=Photo%203%20-%20Left%20side%20of%20helicopter%20and%20engine%20with%20hole%20in%20turbine%20case.-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.