# NTSB WPR12IA248: Eurocopter AS 350 B2, N105TV, Seattle, WA, May 22, 2012 - Type: NTSB incident investigation - Classification: Incident · No injuries · Incident investigation · Final report - Date: May 22, 2012, 14:30 local (21:30 UTC) - Place: Seattle, WA - Coordinates: 47.466945, -122.335281 - Nearby events: https://openairdocs.org/map.md?lat=47.4669&lon=-122.3353&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering: Flight control sys malf/fail](https://openairdocs.org/ntsb-events/333) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report January 13, 2014 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: FAA FSDO - NTSB case key (mKey): 83869 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR12IA248 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/83869/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=83869 - Page: https://openairdocs.org/ntsb/WPR12IA248 ## Probable cause Failure of maintenance personnel to ensure that the tail rotor pitch change link bolt was properly secured, which resulted in an in-flight separation of the bolt and subsequent vibration. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Maintenance: scheduled/routine maintenance](https://openairdocs.org/ntsb-findings/02062010): Personnel issues › Task performance · Maintenance personnel (probable cause); cases with it: [Eurocopter AS 350 B2, 1 case](https://openairdocs.org/ntsb-findings/02062010/cases.md?model=8680950), [All aircraft, 320 cases](https://openairdocs.org/ntsb-findings/02062010/cases.md) - [Misc hardware: fasteners](https://openairdocs.org/ntsb-findings/01071430): Aircraft › Fluids/misc hardware · Incorrect service/maintenance (probable cause); cases with it: [Eurocopter AS 350 B2, 1 case](https://openairdocs.org/ntsb-findings/01071430/cases.md?model=8680950), [All aircraft, 58 cases](https://openairdocs.org/ntsb-findings/01071430/cases.md) - [Tail rotor](https://openairdocs.org/ntsb-findings/01046400): Aircraft › Aircraft propeller/rotor · Malfunction (probable cause); cases with it: [Eurocopter AS 350 B2, 1 case](https://openairdocs.org/ntsb-findings/01046400/cases.md?model=8680950), [All aircraft, 23 cases](https://openairdocs.org/ntsb-findings/01046400/cases.md) - [Maintenance/inspections: scheduled maint checks](https://openairdocs.org/ntsb-findings/01010520): Aircraft › Aircraft handling/service · Incorrect service/maintenance (probable cause); cases with it: [Eurocopter AS 350 B2, 1 case](https://openairdocs.org/ntsb-findings/01010520/cases.md?model=8680950), [All aircraft, 76 cases](https://openairdocs.org/ntsb-findings/01010520/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Prior to flight: Aircraft maintenance event](https://openairdocs.org/ntsb-events/040); cases with it: [Eurocopter AS 350 B2, 1 case](https://openairdocs.org/ntsb-events/040/sequence.md?model=8680950), [All aircraft, 484 cases](https://openairdocs.org/ntsb-events/040/sequence.md) - [Maneuvering: Flight control sys malf/fail](https://openairdocs.org/ntsb-events/333) (defining event); cases with it: [Eurocopter AS 350 B2, 1 case](https://openairdocs.org/ntsb-events/333/sequence.md?model=8680950), [All aircraft, 410 cases](https://openairdocs.org/ntsb-events/333/sequence.md) ## Analysis The pilot reported that he had just entered a slow orbit when the helicopter experienced what he described as a severe vibration. The vibration was continuous and so severe that the pilot diverted to a nearby airport and landed. Postincident examination of the helicopter revealed that one of the tail rotor pitch change link bolts (to the pitch arm) was missing. The incident flight followed a 100-hour maintenance inspection that concluded earlier that day. The inspection included maintenance and service to the tail rotor assembly. The pilot reported that the pitch change link bolt (to pitch arm) was not correctly tightened and secured while in maintenance and subsequently loosened and released during the flight. ## Factual narrative On May 22, 2012, about 1430 Pacific daylight time, a Eurocopter AS-350 B2, N105TV, sustained minor damage following an in-flight separation of a tail rotor pitch change link bolt while maneuvering near the Seattle-Tacoma International Airport (SEA), Seattle, Washington. The airline transport pilot and aerial photographer crewmember were not injured. The helicopter was registered to KING Broadcasting Company, Seattle, Washington, and operated as an electronic news gathering flight under the provisions of 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed and a company flight plan was activated for the flight that originated from Boeing Field (BFI), Seattle, Washington, about 1415. The pilot's planned destination was Seattle Private Number One Heliport (WN01). The pilot reported that he had just entered a slow orbit, about 1,200 feet above the ground, when the helicopter experienced what he described as a severe vibration. The vibration was continuous and so severe that the pilot diverted to BFI for landing. He reported that just before landing, with full right pedal inputs, the helicopter entered a slow turn to the left, which continued until touchdown on the taxiway. The pilot reported that a postincident examination of the helicopter revealed damage to the tail boom assembly and support structure. He reported the exam also revealed that one of the tail rotor pitch change link bolts (to the pitch arm) was missing and likely released during the flight, which resulted in an asymmetrical pitch between the two tail rotor blades and subsequent vibration. The accident flight followed a 100-hour maintenance inspection that concluded earlier that day. The inspection included maintenance and service to the tail rotor assembly. The pilot reported that the pitch change link bolt (to pitch arm) was not correctly tightened and secured while in maintenance and subsequently loosened and released during the flight. ## Aircraft - Registration: [N105TV](https://openairdocs.org/deregistered/N105TV-2015-09-25), registration cancelled 2015-09-25, S/N 2279, built 1989 (OpenAirDocs) - Reported make and model: EUROCOPTER AS 350 B2 - Registry model: [Eurocopter AS 350 B2](https://openairdocs.org/model/eurocopter-as-350-b2) (registry code 8680950) (OpenAirDocs) - Registry engine: [Turbomeca ARRIEL-1D1](https://openairdocs.org/engine/turbomeca-arriel-1d1) (registry code 60053, turbo-shaft) (OpenAirDocs) - Category: Helicopter - Serial number: 2279 - Airframe hours: 11501 - Engines: TURBOMECA ARRIEL 1D1 712 horsepower turbo shaft - Damage: Minor damage - Flight: Other work use, Part 91 - Operator: King Broadcasting Co - Registered owner: King Broadcasting Co - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, May 22, 2012, 1 hours before - Departed: KBFI, Seattle, WA - Destination: Seattle, WA - Flight plan: Company VFR - Airport: BFI, Boeing Field ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 62; injuries: none; flight instructor, airline transport, commercial; airplane ratings: multi-engine land, single-engine sea, single-engine land; instrument ratings: airplane, helicopter; medical: class 2, with waivers/limitations; last flight review December 16, 2011; seat: right; flight hours: 20,423 total, 7,230 in this make and model, 19,426 as pilot in command, 180 in the last 90 days, 40 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 110° at 5 knots - Visibility: 10 statute miles - Lowest ceiling: 2,700 ft broken - Temperature: 54 °F, dew point 48 °F - Altimeter: 29.86 inHg - Observed at: KBFI ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Incident 20120522015139I](https://openairdocs.org/incident/20120522015139I), May 22, 2012: Eurocopter AS 350 B2, Seattle, WA, Minor damage. On may 22,2012, about 1430 pacific daylight time, a Eurocopter AS-350 B2, N105TV, substained minor damage following an in-flight seperation of a tail rotor… ## Docket (3 files) The files NTSB released with the investigation on November 15, 2013, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=83869. 514 KB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 402 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40369761&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Record of Conversation – Pilot (item 2, .PDF, 53 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40403459&FileExtension=.PDF&FileName=Record%20of%20Conversation%20%E2%80%93%20Pilot-Master.PDF - Photo 1. Tail rotor pitch change link with missing bolt (item 3, .PDF, 60 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40403461&FileExtension=.PDF&FileName=Photo%201.%20Tail%20rotor%20pitch%20change%20link%20with%20missing%20bolt-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.