# NTSB CEN21LA165: Hughes 369D, N41AJ, Lake City, KS, March 25, 2021

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Class 4 · Limited · Final report
- Date: March 25, 2021, 12:30 local (17:30 UTC)
- Place: Lake City, KS
- Coordinates: 37.362358, -98.812263
- Nearby events: https://openairdocs.org/map.md?lat=37.3624&lon=-98.8123&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Defining event: [Maneuvering-low-alt flying: Low altitude operation/event](https://openairdocs.org/ntsb-events/220)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed
- Report: Approved by Office Director
- Investigation class: Class 4 - Basic report with no Prelim publish
- NTSB office: Central Region
- NTSB case key (mKey): 102806
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN21LA165
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/102806/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=102806
- Page: https://openairdocs.org/ntsb/CEN21LA165

## Probable cause

The pilot’s failure to maintain clearance from power lines during power line maintenance.

## 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)
- [Performance/control parameters: altitude](https://openairdocs.org/ntsb-findings/01062012): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Hughes Helicopters HUGHES 369D, 10 cases](https://openairdocs.org/ntsb-findings/01062012/cases.md?model=4470706), [All aircraft, 1,310 cases](https://openairdocs.org/ntsb-findings/01062012/cases.md)

## Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event best describes what happened.

- [Maneuvering-low-alt flying: 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

The pilot reported that while hovering near power lines, for the purpose of installing bird diverters, a gust of wind pushed the helicopter “into the OPGW wire.” The pilot repositioned the helicopter away from the wire and then saw it fly up and into the rotor system. He immediately started a controlled landing and safely landed the helicopter. The helicopter sustained substantial damage to all five rotor blades. The pilot reported that there were no mechanical anomalies with the helicopter before the wire strike that would have precluded normal operation. The pilot reported that the helicopter operator is adding local weather stations to augment reported weather when the flight crews are working in remote areas. Additionally, for skid operations, the operator has restricted the steady state wind and gust spreads by zone for the helicopter.

## Aircraft

- Registration: [N41AJ](https://openairdocs.org/aircraft/N41AJ), registered now, S/N 480299D, built 1978 (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: [Rolls-Royce 250-C20](https://openairdocs.org/engine/rolls-royce-250-c20) (registry code 54178, turbo-shaft) (OpenAirDocs)
- Category: Helicopter
- Serial number: 480299D
- Year built: 1978
- Airframe hours: 2579
- Engines: Rolls Royce 250-C20 400 horsepower turbo shaft
- Damage: Substantial damage
- Flight: External load, Part 133
- Operator: English Air Service LLC
- Registered owner: English Air Service LLC
- Airworthiness certificate: Standard, Normal
- Last inspection: 100 hour, February 26, 2021
- Departed: PTT, Pratt, KS
- Destination: Same as departure
- Airport: N/A
- Equipment: ADS-B

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 66; injuries: none; airline transport; airplane ratings: single-engine land; medical: class 2, with waivers/limitations; last flight review October 13, 2020; seat: left; restraint: 4-point; flight hours: 22,704 total, 880 in this make and model, 22,350 as pilot in command

## Weather

- Conditions: Visual (VMC), Day
- Wind: 345° at 8 knots
- Visibility: 10 statute miles
- Temperature: 44 °F, dew point 43 °F
- Altimeter: 27.78 inHg
- Observed at: PTT, 25 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 20210325006839A](https://openairdocs.org/incident/20210325006839A), Mar 25, 2021: Hughes 369D, Lake City, KS, Substantial damage. The pilot of the helicopter was flying a strapped in lineman attaching bird diverters to opgw wire (fiber optic cable) with 6-9 knot winds with VMC conditions.…

## Docket (2 files)

The files NTSB released with the investigation on August 27, 2021, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=102806. 4.3 MB in all.

- Photo array (item 1, PDF, 6 pages, 544 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12525188&FileExtension=pdf&FileName=Photo%20Array-Rel.pdf
- Pilot/operator aircraft accident report, NTSB form 6120.1 (item 2, PDF, 9 pages, 3.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12525278&FileExtension=pdf&FileName=6120_Redacted-Rel.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.

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