# NTSB ANC91GAMS1: Gulfstream Aerospace 690C, N45Q, Deadhorse, AK, October 12, 1990

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Final report
- Date: October 11, 1990, 17:30 local (Oct 12, 1990, 01:30 UTC)
- Place: Deadhorse, AK
- Coordinates: 70.333335, -150.933334
- Nearby events: https://openairdocs.org/map.md?lat=70.3333&lon=-150.9333&mi=10
- Phase of flight: [Unknown](https://openairdocs.org/ntsb-phases/990) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 3 fatal
- Status: Completed, report May 30, 2003
- Report: Approved by Office Director
- NTSB office: Alaska Regional Office
- Parties: Federal Aviation Administration
- NTSB case key (mKey): 56460
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC91GAMS1
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/56460/pdf
- Page: https://openairdocs.org/ntsb/ANC91GAMS1

## Probable cause

Missing aircraft.

## Sequence of events

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

- Missing aircraft, unknown
  - reason for occurrence undetermined

## Analysis

The airplane with a certificated airline transport pilot and two passengers aboard departed on a US Department of the Interior, public use flight over the Arctic Ocean.  The purpose of the flight was to locate radio collared polar bears.  Radar contact with the airplane was lost while it was maneuvering at 22,000 feet msl about 200 miles from shore.  The airplane did not reach the intended destination, and neither the airplane nor its occupants were located during an extensive search.

## Factual narrative

On October 11, 1990, about 1730 Alaska daylight time, a wheel-equipped Gulfstream Aerospace 690C Turbine Commander airplane, N45Q, is presumed to have crashed in the Arctic Ocean about 200 miles north-northwest of Deadhorse, Alaska.  Neither the airplane nor its occupants have been located.  The airplane was being operated by the US Department of the Interior, as a visual flight rules (VFR) public use local game management flight, for the purpose of locating radio collared polar bears, when the accident occurred.  The airplane, registered to Bowhead Equipment Company of Seattle, Washington, and operated by Alaska Helicopters, Inc. of Anchorage, Alaska, is presumed to have been destroyed.  The certificated airline transport pilot, and the two passengers, are presumed to have received fatal injuries.  Visual meteorological conditions prevailed at the point of departure.  A VFR flight plan was filed by the pilot for a 5.5 hour flight orginating and terminating at Deadhorse.  The accident flight originated at the Deadhorse Airport about 1429.

According to information received from the Federal Aviation Administration's (FAA), Air Route Traffic Control Center, radar contact was lost with the accident airplane while it was maneuvering at 22,000 feet msl, about 200 miles north-northwest of Deadhorse.

The accident airplane did not reach the intended destination of Deadhorse, and was not located at any airport.  The FAA issued an alert notice (ALNOT) at 2221.  Search personnel began an extensive search effort that included a high altitude, special radar-equipped airplane, surface vessels, and ground search personnel.  The search was suspended on October 26, 1990.

## Aircraft

- Registration: [N45Q](https://openairdocs.org/deregistered/N45Q-1994-04-26), registration cancelled 1994-04-26, S/N 11623 (OpenAirDocs)
- Reported make and model: Gulfstream Aerospace 690C
- Registry model: [Gulfstream AM Corp Comm Div 690C](https://openairdocs.org/model/gulfstream-am-corp-comm-div-690c) (registry code 3970404) (OpenAirDocs)
- Category: Airplane
- Serial number: 11623
- Airframe hours: 3115
- Engines: Garrett TPE331-5-254K 718 horsepower turbo prop
- Damage: Destroyed
- Flight: Public aircraft, Public use
- Operator: Alaska Helicopters Inc
- Registered owner: Bowhead Equipment Comapny
- Airworthiness certificate: Standard, Normal
- Last inspection: Continuous airworthiness, October 1, 1991, 13.8 hours before
- Departed: PALP, Deadhorse, AK
- Destination: PALP, Deadhorse, AK
- Flight plan: VFR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 50; injuries: fatal; airline transport; airplane ratings: single-engine sea, single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; last flight review October 2, 1991; seat: left; flight hours: 17,500 total, 1,200 in this make and model, 16,000 as pilot in command, 153 in the last 90 days, 10 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day

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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