# NTSB ANC83IA089: Boeing Vertol 234ER, N234BV, Mekoryuk, AK, June 1, 1983

- Type: NTSB incident investigation
- Classification: Incident · No injuries · Incident investigation · Final report
- Date: June 1, 1983, 12:58 local (20:58 UTC)
- Place: Mekoryuk, AK
- Coordinates: 60.370185, -166.269638 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=60.3702&lon=-166.2696&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 19 uninjured
- Status: Completed
- Report: Approved by Office Director
- NTSB office: Alaska Regional Office
- NTSB case key (mKey): 4089
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC83IA089
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/4089/pdf
- Page: https://openairdocs.org/ntsb/ANC83IA089

## Sequence of events

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

- Loss of engine power(total) - mech failure/malf, climb - to cruise
  - accessory drive assy - failure,total (cause)
  - precautionary landing - performed, pilot in command
  - fuel system,fuel jettison system - failure,partial (contributing factor)
  - load jettison - performed, pilot in command
  - weather condition - low ceiling
  - weather condition - fog

## Analysis

WHILE CLIMBING IN IFR CONDITIONS AFTER TAKEOFF, THE #1 ENG LOST POWER. THE PLT DUMPED FUEL & LANDED ON AN OIL EXPLORATION PLATFORM. WHILE DUMPING FUEL, THE #1 JETTISON SYS OPERATED NORMALLY, BUT THE CIRUIT BREAKER POPPED ON THE #2 SYS. THE AIRCREW RESET THE CIRCUIT BREAKER & WERE ABLE TO OPEN THE VALVE, BUT THE CIRCUIT BREAKER POPPED AGAIN. THEY WERE ABLE TO CLOSE THE #2 JETTISON VALVE BY HOLDING THE CIRCUIT BREAKER IN. AN INVESTIGATION REVEALED THAT THE LOWER ACCESSORY LEVEL GEAR, PN 2-070-024-01, IN THE #1 ENG, HAD FAILED.

## Aircraft

- Registration: N234BV (not matched to a registry record)
- Reported make and model: BOEING VERTOL 234ER
- Category: Helicopter
- Serial number: MJ016
- Airframe hours: 99
- Engines: LYCOMING AL5512 4075 horsepower turbo shaft
- Damage: No damage
- Flight: Business, Part 91 subpart F
- Operator: Atlantic Richfield Co.
- Registered owner: 234 I Inc.C/O Boeing Vertol
- Airworthiness certificate: Standard, Transport
- Last inspection: Continuous airworthiness, May 29, 1983, 9 hours before
- Departed: 708, BERING SEA, AK
- Destination: OME, NOME, AK
- Flight plan: IFR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 33; airline transport; airplane ratings: multi-engine land, single-engine land; instrument ratings: helicopter, airplane; medical: class 1, valid medical--w/ waivers/lim; seat: right; flight hours: 3,990 total, 30 in this make and model, 30 in the last 90 days, 4 in the last 24 hours

## Weather

- Conditions: Instrument (IMC), Day
- Wind: 290° at 4 knots
- Lowest ceiling: 300 ft overcast
- Temperature: 39 °F, dew point 34 °F

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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