# NTSB ANC12CA100: Aerospatiale AS350 B2, N178CH, Talkeetna, AK, September 1, 2012 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: August 31, 2012, 18:10 local (Sep 1, 2012, 02:10 UTC) - Place: Talkeetna, AK - Coordinates: 62.766666, -148.583328 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=62.7667&lon=-148.5833&mi=10 - Phase of flight: [Standing](https://openairdocs.org/ntsb-phases/150) (OpenAirDocs' grouping) - Defining event: [Standing-engine(s) operating: Miscellaneous/other](https://openairdocs.org/ntsb-events/900) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report December 19, 2012 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - Parties: Federal Aviation Administration - NTSB case key (mKey): 84925 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC12CA100 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/84925/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=84925 - Page: https://openairdocs.org/ntsb/ANC12CA100 ## Probable cause The entanglement of a plastic tarp in the helicopter’s tail rotor after becoming dislodged from its securement. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Tail rotor drive system: tail rotor drive shaft](https://openairdocs.org/ntsb-findings/01046510): Aircraft › Aircraft propeller/rotor · Damaged/degraded; cases with it: [All aircraft, 25 cases](https://openairdocs.org/ntsb-findings/01046510/cases.md) - [Object/animal/substance: debris/dirt/foreign object](https://openairdocs.org/ntsb-findings/03022055): Environmental issues › Physical environment · Effect on equipment (probable cause); cases with it: [All aircraft, 101 cases](https://openairdocs.org/ntsb-findings/03022055/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Standing-engine(s) operating: Miscellaneous/other](https://openairdocs.org/ntsb-events/900) (defining event); cases with it: [All aircraft, 1,556 cases](https://openairdocs.org/ntsb-events/900/sequence.md) ## Analysis The pilot landed a high-skid, turbine-powered helicopter at a remote construction site, which contained several bags of cement that were covered by a plastic tarp. The plastic tarp was secured by a nylon strap that was wrapped around the bags. The pilot reported that after landing near the bags of cement, he retarded the engine throttle to flight idle to begin the mandatory 2-minute engine cool down procedure. During the engine cool down, the pilot felt an abrupt airframe vibration, so he immediately closed the engine throttle and performed an emergency engine shutdown. A postflight inspection revealed that the plastic tarp had dislodged from the nylon strap, and it subsequently became entangled in the tail rotor hub and blade assembly. As a result, the helicopter sustained substantial damage to the tail rotor drive system and tailboom. The pilot said there were no preaccident mechanical anomalies with the helicopter that would have precluded normal operation. ## Factual narrative The pilot landed a high skid, turbine-powered helicopter at a remote construction site, which contained several bags of cement that were covered by a plastic tarp. The plastic tarp was secured by a nylon strap that was wrapped around the bags. The pilot reported that after landing near the bags of cement, he retarded the engine throttle to flight idle to begin the mandatory 2-minute engine cool down procedure. During the engine cool down the pilot felt an abrupt airframe vibration, so he immediately closed the engine throttle, and did an emergency engine shutdown. A postflight inspection revealed that the plastic tarp had dislodged from the nylon strap, and it subsequently became entangled in the tail rotor hub and blade assembly. As a result, the helicopter sustained substantial damage to the tail rotor drive system and tail boom. The pilot said there were no preaccident mechanical problems with the helicopter. ## Aircraft - Registration: N178CH (not matched to a registry record) - Reported make and model: AEROSPATIALE AS350 B2 - Category: Helicopter - Serial number: 2042 - Airframe hours: 8741 - Engines: TURBOMECA Arriel 731 horsepower turbo shaft - Damage: Substantial damage - Flight: External load, Part 133 - Operator: Last Frontier Air Venture - Registered owner: Bell Leasing LLC - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, August 23, 2012 - Departed: Talkeetna, AK - Destination: Talkeetna, AK - Flight plan: Company VFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 64; injuries: none; commercial; airplane ratings: single-engine sea, multi-engine sea, single-engine land, multi-engine land; instrument ratings: airplane, helicopter; medical: class 1, with waivers/limitations; seat: right; flight hours: 14,000 total, 1,000 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: variable at 10 knots - Visibility: 30 statute miles - Lowest ceiling: 6,000 ft overcast - Temperature: 50 °F ## 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 20120831018509A](https://openairdocs.org/incident/20120831018509A), Aug 31, 2012: Aerospatiale AS350 B2 ECUREUIL, Talkeetna, AK, Substantial damage. After placing an external load, the pilot descended to land in the same location he, and other pilots had landed several times previously. Near the landing… ## Docket (1 files) The files NTSB released with the investigation on October 27, 2012, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=84925. 808 KB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 808 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40379753&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.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.