# NTSB ATL89FA116: MBB BK-117-A-3, N39187, Coinjock, NC, March 27, 1989

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Field investigation · Final report
- Date: March 26, 1989, 21:05 local (Mar 27, 1989, 02:05 UTC)
- Place: Coinjock, NC
- Coordinates: 36.340198, -75.949172 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=36.3402&lon=-75.9492&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 2 fatal
- Status: Completed, report May 15, 1992
- Report: Approved by Office Director
- NTSB case key (mKey): 7885
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ATL89FA116
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/7885/pdf
- Page: https://openairdocs.org/ntsb/ATL89FA116

## Probable cause

FAILURE OF THE CELLULAR COMPANY TO PROPERLY INSTALL AN OPERATIONAL LIGHTING SYSTEM ON A NEWLY CONSTRUCTED TRANSMISSION TOWER.  DARKNESS AND THE COMPANY'S FAILURE TO NOTIFY FLIGHT SERVICE OF THE UNLIGHTED TOWER WERE RELATED FACTORS.

## Sequence of events

In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf).

- In flight collision with object, cruise
  - light condition - dark night (contributing factor)
  - object - tower (cause)
  - remedial action - not performed, other person (cause)
  - information - not issued, other person (contributing factor)
- In flight collision with terrain/water, descent - uncontrolled

## Analysis

THE FLT WAS RETURNING TO HOMEBASE ALONG A NORMALLY TRAVELED ROUTE, WHEN THE HELICOPTER COLLIDED WITH A NEWLY CONSTRUCTED ANTENNA FOR A CELLULAR PHONE OPN. THIS TOWER HAD BEEN COMPLETED ON THE SAME DAY AS THE ACDNT. ACCORDING TO THE FIELD SUPERVISOR, THE LAST 100 FT SECTION OF THE 240 FT TOWER WAS COMPLETED NEAR SUNSET & THERE WAS NOT ENOUGH TIME TO COMPLETE THE ELECTRICAL CONNECTION TO THE INSTALLED BEACON. THE SUPERVISOR FAILED TO ADVISE FLIGHT SERVICE OF THE TOWER HEIGHT & THAT THE BEACON WAS NOT IN OPN. A WRECKAGE EXAM INDICATED THAT THE HELICOPTER ROTOR SYSTEM COLLIDED WITH THE TOWER ABOUT 15 FT FROM THE TOP. ACCORDING TO ANOTHER PLT AT THE COUNTY'S FLT OPN, MOST FLTS WERE FLOWN BETWEEN 100 & 500 FT AGL.

## Aircraft

- Registration: [N39187](https://openairdocs.org/deregistered/N39187-2013-06-12), registration cancelled 2013-06-12, S/N S-7010, built 1984 (OpenAirDocs)
- Reported make and model: MBB BK-117-A-3
- Registry model: [Messerschmitt BK 117](https://openairdocs.org/model/messerschmitt-bk-117) (registry code 5626010) (OpenAirDocs)
- Registry engine: [Lycoming LTS-101 series](https://openairdocs.org/engine/lycoming-lts-101-series) (registry code 41560, turbo-shaft) (OpenAirDocs)
- Category: Helicopter
- Serial number: 7010
- Airframe hours: 1090
- Engines: LYCOMING LTS-101-650 650 horsepower turbo shaft
- Damage: Destroyed
- Flight: Public aircraft, Part 91
- Registered owner: Dare County
- Airworthiness certificate: Standard, Transport
- Last inspection: Annual, February 11, 1989, 226 hours before
- Departed: NGH, NORFOLK, VA
- Destination: MANTEO, NC

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 53; commercial; airplane ratings: single-engine land; medical: class 2, valid medical--w/ waivers/lim; seat: right; flight hours: 8,134 total, 658 in this make and model, 19 in the last 90 days

## Weather

- Conditions: Visual (VMC), Night/dark
- Visibility: 7 statute miles
- Lowest ceiling: none
- Temperature: 48 °F, dew point 45 °F
- Observed at: 106H

## 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 19890326064979A](https://openairdocs.org/incident/19890326064979A), Mar 26, 1989: Bolkms BK117A3, Coinjock, NC, Destroyed, 2 fatal. Struck a unlighted newly installed electronic 340 AGL tower. County public aircraft returning from ambulance flight

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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