# NTSB ERA09LA194: Hughes 369D, N369RT, Lee, MA, March 10, 2009 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Limited investigation · Final report - Date: March 10, 2009, 15:07 local (19:07 UTC) - Place: Lee, MA - Coordinates: 42.284999, -73.238609 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=42.2850&lon=-73.2386&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering-hover: Low altitude operation/event](https://openairdocs.org/ntsb-events/220) - Highest injury: Serious injuries - Injuries: 3 serious - Status: Completed, report March 23, 2010 - Report: Approved by Office Director - NTSB office: Eastern Region Aviation - Parties: FAA/FSDO - NTSB case key (mKey): 73472 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA09LA194 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/73472/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=73472 - Page: https://openairdocs.org/ntsb/ERA09LA194 ## Probable cause The pilot's failure to maintain clearance from the overhead wire. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Attention/monitoring: monitoring environment](https://openairdocs.org/ntsb-findings/02021545): Personnel issues › Psychological · Pilot (probable cause); cases with it: [Hughes Helicopters HUGHES 369D, 9 cases](https://openairdocs.org/ntsb-findings/02021545/cases.md?model=4470706), [All aircraft, 809 cases](https://openairdocs.org/ntsb-findings/02021545/cases.md) - [Object/animal/substance: wire](https://openairdocs.org/ntsb-findings/03022032): Environmental issues › Physical environment · Awareness of condition (probable cause); cases with it: [Hughes Helicopters HUGHES 369D, 11 cases](https://openairdocs.org/ntsb-findings/03022032/cases.md?model=4470706), [All aircraft, 588 cases](https://openairdocs.org/ntsb-findings/03022032/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Maneuvering-hover: Low altitude operation/event](https://openairdocs.org/ntsb-events/220) (defining event); cases with it: [Hughes Helicopters HUGHES 369D, 10 cases](https://openairdocs.org/ntsb-events/220/sequence.md?model=4470706), [All aircraft, 780 cases](https://openairdocs.org/ntsb-events/220/sequence.md) ## Analysis While hovering the helicopter during the installation of a transmission wire about 70 feet above the ground, the pilot inadvertently allowed the left horizontal stabilizer to move laterally until it was beneath the wire. When the pilot attempted to climb the helicopter away from the wire, the wire hooked the stabilizer. The helicopter subsequently pitched forward and the main rotor blades and rotor mast also became entangled with the wire. The main rotor blades and tail boom then broke away from the helicopter, which spun once or twice before hitting the ground. There were no mechanical anomalies noted with the helicopter and no appreciable wind. ## Factual narrative On March 10, 2009, at 1507 eastern daylight time, a Hughes 369D, N369RT, operated by Air2 LLC, was substantially damaged when it became entangled in a transmission wire in Lee, Massachusetts. The certificated airline transport pilot and two onboard linemen were seriously injured. Visual meteorological conditions prevailed, and no flight plan had been filed for the local flight which began near an electrical substation close to the transmission lines. The flight was conducted under the provisions of 14 Code of Federal Regulations Part 133. According to an employee of the power company that had contracted the helicopter, the crew was involved with the installation of an overhead optical ground wire (OPGW). The OPGW was being installed on "H-frame" wood structures, about 70 feet above the ground. The employee began to take photographs of the aerial work, and noticed that as the helicopter began to move away from a newly installed OPGW, it appeared that the wire was hooked onto the left horizontal stabilizer. A photograph that he took at the same time also revealed that that the OPGW wire was hooked, in the vicinity of, and inboard the left vertical fin located on the outboard edge of the stabilizer. According to a police officer providing security at the site, he observed the helicopter take off and land numerous times from an electric substation about 500 feet west of his location. While in flight, the helicopter would fly to, and assist as necessary with the installation of the OPGW line. About 1220, the police officer observed two linemen climb the utility pole nearest the accident site "apparently to fix a pulley problem." The repair was made without assistance of the helicopter. The helicopter subsequently flew near this site several times after that, but the police officer was not sure if any linemen were onboard. About 1450, the police officer observed the helicopter again fly near the utility pole, and two linemen exited the helicopter, on to the pole. The helicopter then moved away from the pole while the linemen did some more work. The police officer also noted no mechanical anomalies with the helicopter, and no "appreciable" wind. The helicopter then returned to the pole, and the pilot positioned the left skid either against, or very close to the pole. The linemen then transitioned from the pole to the left skid. Immediately afterwards, the police officer noticed that the "tail section" of the helicopter moved laterally, to where "a small section of tail fin" was positioned under the same wire that the linemen had been working on. Then, as the helicopter slowly climbed away from the pole, a piece of the "tail section" was hooked by the wire. There was initially some slack in the wire; however, when the slack played out, the helicopter pitched forward, and the main rotor then became entangled in the wire. The main rotor blades then broke away from the helicopter, which spun one or two times before hitting the ground. Additionalphotographs of the wreckage revealed a mid-span cut, beginning at the leading edge of the left horizontal stabilizer, and wire segments wrapped multiple times around one of the main rotor blades as well as the rotor mast. The rotor blades were separated from the mast, and the tail boom was separated from the main wreckage. Weather, recorded at the airport in Pittsfield, Massachusetts, about 8 nautical miles to the north, at 1454, included overcast skies and winds from 190 degrees true at 4 knots. ## Aircraft - Registration: [N369RT](https://openairdocs.org/deregistered/N369RT-2012-09-04), registration cancelled 2012-09-04, S/N 1000819D, built 1980 (OpenAirDocs) - Reported make and model: HUGHES 369D - Registry model: [Hughes Helicopters HUGHES 369D](https://openairdocs.org/model/hughes-helicopters-hughes-369d) (registry code 4470706) (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: 1000819D - Airframe hours: 1345 - Engines: ALLISON 250 SER 250HP 250 horsepower turbo shaft - Damage: Substantial damage - Flight: Other work use, Part 133 - Operator: Air2 LLC - Registered owner: Air2 LLC - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, February 10, 2009, 9 hours before - Departed: Lee, MA - Destination: Lee, MA ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 40; injuries: serious; airline transport; instrument ratings: helicopter; medical: class 1; last flight review August 13, 2008; seat: left; flight hours: 5,708 total, 286 in this make and model, 4,542 as pilot in command, 54 in the last 90 days, 12 in the last 30 days, 3 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 190° at 4 knots - Visibility: 10 statute miles - Lowest ceiling: 2,200 ft overcast - Temperature: 37 °F, dew point 30 °F - Altimeter: 30.00 inHg - Observed at: PSF, 8 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 20090310004269A](https://openairdocs.org/incident/20090310004269A), Mar 10, 2009: Hughes 369D, Lee, MA, Destroyed. (-23) The tail boom of the helicopter became tangled with the wire that the helicopter crew was working with. The wire became caught in the rotor blades and… ## Docket (5 files) The files NTSB released with the investigation on October 21, 2009, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=73472. 11.4 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 467 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40319177&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Witness Statements (item 2, .PDF, 241 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40319179&FileExtension=.PDF&FileName=Witness%20Statements-Redacted.PDF - Private Photo: Wire Hooked on Horizontal Stabilizer (item 3, .PDF, 36 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40319689&FileExtension=.PDF&FileName=Private%20Photo%3A%20Wire%20Hooked%20on%20Horizontal%20Stabilizer-Master.PDF - FAA Photo: Helicopter Main Wreckage (item 4, .PDF, 5.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40319688&FileExtension=.PDF&FileName=FAA%20Photo%3A%20Helicopter%20Main%20Wreckage-Master.PDF - FAA Photo: Wire Wrapped Around Mast (item 5, .PDF, 5.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40319687&FileExtension=.PDF&FileName=FAA%20Photo%3A%20Wire%20Wrapped%20Around%20Mast-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.