# NTSB CEN10IA397: Bell 206, N523RL, Gulf of Mexico, LA, July 12, 2010 - Type: NTSB incident investigation - Classification: Incident · No injuries · Incident investigation · Final report - Date: July 12, 2010, 14:28 local (19:28 UTC) - Place: Gulf of Mexico, LA - Coordinates: 31.169483, -91.866859 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=31.1695&lon=-91.8669&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Defining event: [Approach-VFR go-around: Loss of control in flight](https://openairdocs.org/ntsb-events/240) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report August 7, 2012 - Report: Approved by Office Director - NTSB office: Central Region - Parties: FAA Baton Rouge FSDO, Bell Helicopter Textron, Transportation Safety Board of Canada - NTSB case key (mKey): 76634 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN10IA397 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/76634/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=76634 - Page: https://openairdocs.org/ntsb/CEN10IA397 ## Probable cause Improper reassembly of the collective flight controls by maintenance personnel. Contributing to the incident were inadequate postmaintenance examinations by maintenance personnel and inadequate preflight inspections by two pilots. ## 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 service/maintenance (probable cause); cases with it: [Bell 206-L4, 1 case](https://openairdocs.org/ntsb-findings/01046710/cases.md?model=1182110), [All aircraft, 28 cases](https://openairdocs.org/ntsb-findings/01046710/cases.md) - [Maintenance: scheduled/routine maintenance](https://openairdocs.org/ntsb-findings/02062010): Personnel issues › Task performance · Maintenance personnel (probable cause); cases with it: [Bell 206-L4, 2 cases](https://openairdocs.org/ntsb-findings/02062010/cases.md?model=1182110), [All aircraft, 320 cases](https://openairdocs.org/ntsb-findings/02062010/cases.md) - [Inspection: post maintenance inspection](https://openairdocs.org/ntsb-findings/02061515): Personnel issues › Task performance · Maintenance personnel (probable cause); cases with it: [Bell 206-L4, 1 case](https://openairdocs.org/ntsb-findings/02061515/cases.md?model=1182110), [All aircraft, 57 cases](https://openairdocs.org/ntsb-findings/02061515/cases.md) - [Inspection: preflight inspection](https://openairdocs.org/ntsb-findings/02061510): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Bell 206-L4, 1 case](https://openairdocs.org/ntsb-findings/02061510/cases.md?model=1182110), [All aircraft, 551 cases](https://openairdocs.org/ntsb-findings/02061510/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: [Bell 206-L4, 1 case](https://openairdocs.org/ntsb-events/040/sequence.md?model=1182110), [All aircraft, 484 cases](https://openairdocs.org/ntsb-events/040/sequence.md) - [Prior to flight: Aircraft inspection event](https://openairdocs.org/ntsb-events/050); cases with it: [Bell 206-L4, 1 case](https://openairdocs.org/ntsb-events/050/sequence.md?model=1182110), [All aircraft, 229 cases](https://openairdocs.org/ntsb-events/050/sequence.md) - [Approach-VFR pattern final: Loss of control in flight](https://openairdocs.org/ntsb-events/240); cases with it: [Bell 206-L4, 7 cases](https://openairdocs.org/ntsb-events/240/sequence.md?model=1182110), [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md) - [Approach-VFR go-around: Loss of control in flight](https://openairdocs.org/ntsb-events/240) (defining event); cases with it: [Bell 206-L4, 7 cases](https://openairdocs.org/ntsb-events/240/sequence.md?model=1182110), [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md) - [Landing: Loss of control in flight](https://openairdocs.org/ntsb-events/240); cases with it: [Bell 206-L4, 7 cases](https://openairdocs.org/ntsb-events/240/sequence.md?model=1182110), [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md) - [Landing-landing roll: Runway excursion](https://openairdocs.org/ntsb-events/300); cases with it: [Bell 206-L4, 1 case](https://openairdocs.org/ntsb-events/300/sequence.md?model=1182110), [All aircraft, 3,643 cases](https://openairdocs.org/ntsb-events/300/sequence.md) ## Analysis According to the pilot, the helicopter was on final approach to a platform in the Gulf of Mexico when he raised the collective to perform a go-around. However, the helicopter did not respond properly; rather, its performance and torque indications remained fixed at 45 percent. The pilot began a slow climb and diverted to a land-based airport at a cruise speed of about 60 knots. Because of a complete loss of collective pitch control, the pilot made a running landing on the runway at the airport, touching down about 45 knots. The helicopter came to a stop in the grass about 100 feet past the end of the runway. An examination of the helicopter revealed that several fasteners were missing from the top clevis of the collective control tube, which led to the control tube becoming disconnected from the collective pitch arm on the swash plate. The missing fasteners were found loose on the deck in the transmission compartment. Records showed that maintenance to reinstall the transmission and main rotor hub had been completed about 6 flight hours before the incident and that several mechanics and two pilots had examined the helicopter before the incident flight without noting the improperly secured/missing fasteners. ## Factual narrative On July 12, 2010, about 1428 central daylight time, a Bell 206 L4 helicopter, N523RL, sustained minor damage after a flight control malfunction over the Gulf of Mexico approximately 62 miles south of Patterson, Louisiana. The commercial pilot and one passenger were not injured. The helicopter was owned and operated by Rotorcraft Leasing Company LLC, Broussard, Louisiana. A company flight plan had been filed for the 14 Code of Federal Regulations Part 135 passenger flight. Visual meteorological conditions prevailed at the time of the incident. The helicopter was attempting to land at a production platform in Eugene Island block 208-K after departing another platform approximately one mile away. According to the pilot, while on final approach to the platform, he raised the collective to perform a go-around, but the helicopter did not respond. The pilot noted that the helicopter performance and torque indication remained fixed at 45 percent. There were no abnormal noises, vibrations, or instrument indications. The pilot initiated a slow climb to 1,000 feet above ground level and diverted to Harry P. Williams Memorial Airport (PTN), Patterson, Louisiana, at a cruise speed of about 60 knots. On his first approach to runway 24, the pilot was not able to slow the helicopter and executed a go-around. On his second approach, with a complete loss of collective pitch control, the pilot made a successful running landing, touching down about 45 knots. The helicopter came to a stop in the grass about 100 feet past the end of the runway. The Federal Aviation Administration (FAA) inspectors who responded to the scene reported that the fasteners were missing from the top clevis of the collective control tube, mounted above the collective bellcrank. The control tube had subsequently become disconnected from the collective pitch arm on the swashplate. There was no deformation, bending, elongation, or damage in that area. The missing fasteners were found loose on the deck in the transmission compartment. Maintenance to reinstall the transmission and main rotor hub had been completed on July 7, 2010. Investigators were unable to establish why these fasteners were not properly secured, as several mechanics and pilots had examined the helicopter prior to the incident flight. ## Aircraft - Registration: [N523RL](https://openairdocs.org/aircraft/N523RL), registered now, S/N 52321, built 2005 (OpenAirDocs) - Reported make and model: BELL 206 (L4) - Registry model: [Bell 206-L4](https://openairdocs.org/model/bell-206-l4) (registry code 1182110) (OpenAirDocs) - Registry engine: [Rolls-Royce 250 20&30 series](https://openairdocs.org/engine/rolls-royce-250-20-30-series) (registry code 54584, turbo-shaft) (OpenAirDocs) - Category: Helicopter - Serial number: 52321 - Airframe hours: 4399 - Engines: ALLISON 250 650 horsepower turbo shaft - Damage: Minor damage - Flight: Part 135 - Operator: Rotorcraft Leasing Company LLC - Registered owner: Rotorcraft Leasing Company LLC - Airworthiness certificate: Standard, Normal - Last inspection: AAIP, July 7, 2010, 6 hours before - Departed: NONE, Gulf of Mexico, LA - Destination: NONE, Gulf of Mexico, LA - Flight plan: Company VFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 26; injuries: none; commercial; instrument ratings: helicopter; medical: class 2, without waivers/limitations; last flight review February 9, 2010; seat: right; flight hours: 1,819 total, 573 in this make and model, 123 in the last 90 days, 39 in the last 30 days, 4 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 240° at 10 knots, gusting 14 - Visibility: 10 statute miles - Lowest ceiling: 4,400 ft - Temperature: 93 °F, dew point 30 °F - Altimeter: 29.95 inHg - Observed at: KPTN, 62 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). - [Incident 20100712051679I](https://openairdocs.org/incident/20100712051679I), Jul 12, 2010: Bell 206-L4, Patterson, LA, No damage. While on final approach to an offshore platform the pilot reported that he was experiencing a collective pitch control malfunction. The helicopter pilot… ## Docket (9 files) The files NTSB released with the investigation on June 18, 2012, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=76634. 8.2 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 1.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40367549&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Mechanics' Statements (item 2, .PDF, 678 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40367550&FileExtension=.PDF&FileName=Mechanics%27%20Statements-Redacted.PDF - FAA Inspector Comments (item 3, .PDF, 73 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40369263&FileExtension=.PDF&FileName=FAA%20Inspector%20Comments-Master.PDF - Map and Airport Diagram (item 4, .PDF, 1.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40369271&FileExtension=.PDF&FileName=Map%20and%20Airport%20Diagram-Master.PDF - Weather Summary (item 5, .PDF, 246 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40369272&FileExtension=.PDF&FileName=Weather%20Summary-Master.PDF - Photo 1 - Transmission (FAA Photo) (item 6, .PDF, 1.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40369287&FileExtension=.PDF&FileName=Photo%201%20-%20Transmission%20%20(FAA%20Photo)-Master.PDF - Photo 2 - Cyclic Control Tube (FAA Photo) (item 7, .PDF, 1.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40369279&FileExtension=.PDF&FileName=Photo%202%20-%20Cyclic%20Control%20Tube%20%20(FAA%20Photo)-Master.PDF - Photo 3 - Collective Control Tube (FAA Photo) (item 8, .PDF, 1.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40369284&FileExtension=.PDF&FileName=Photo%203%20-%20Collective%20Control%20Tube%20%20(FAA%20Photo)-Master.PDF - Photo 4 - Fasteners (FAA Photo) (item 9, .PDF, 868 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40369285&FileExtension=.PDF&FileName=Photo%204%20-%20Fasteners%20%20(FAA%20Photo)-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.