# NTSB ANC90LA068: Artic Interstate S1B1, N73AR, Talkeetna, AK, May 14, 1990

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: May 13, 1990, 19:00 local (May 14, 1990, 03:00 UTC)
- Place: Talkeetna, AK
- Coordinates: 62.450824, -149.790634 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=62.4508&lon=-149.7906&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed, report September 28, 1992
- Report: Approved by Office Director
- NTSB office: Alaska Regional Office
- NTSB case key (mKey): 5363
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC90LA068
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/5363/pdf
- Page: https://openairdocs.org/ntsb/ANC90LA068

## Probable cause

FUEL CONTAMINATION WHICH PRECLUDED THE ENGINE FROM DEVELOPING THE NECESSARY POWER TO CLEAR THE MOUNTAIN RIDGE.

## Sequence of events

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

- Loss of engine power(partial) - nonmechanical, climb
  - fluid,fuel - contamination (cause)
- Main gear collapsed, landing - roll
  - terrain condition - rough/uneven (contributing factor)

## Analysis

THE PILOT-IN-COMMAND ADDED FULL POWER AND ATTEMPTED TO CLIMB OVER A RIDGE WHEN THE ENGINE BEGAN TO SPUTTER. HE WAS FORCED TO LAND ON UNIMPROVED TERRAIN. EXAMINATION OF THE FUEL IN THE AIRPLANE REVEALED BROWN FLAKES WHICH WERE EXAMINED AND FOUND TO BE FLAKES OF GASOLINE VARNISH. THE PILOT STATED THE AIRPLANE HAD SAT WITHOUT OPERATING FOR A LONG TIME PRIOR TO HIS PURCHASE OF THE AIRPLANE.

## Aircraft

- Registration: [N73AR](https://openairdocs.org/deregistered/N73AR-2014-12-03), registration cancelled 2014-12-03, S/N 1024 (OpenAirDocs)
- Reported make and model: Artic Aircraft Corp. INTERSTATE S1B1 (INTERSTATE)
- Registry model: [Arctic S-1B2](https://openairdocs.org/model/arctic-s-1b2) (registry code 0790208) (OpenAirDocs)
- Category: Airplane
- Serial number: 1024
- Airframe hours: 349
- Engines: LYCOMING O-320-B2B 160 horsepower reciprocating
- Damage: Substantial damage
- Flight: Business, Part 91
- Registered owner: Ralph L. Loper
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, March 17, 1990, 58 hours before
- Departed: Z70, CANTWELL, AK
- Airport: NONE

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 38; private; airplane ratings: single-engine land; medical: class 3, valid medical--no waivers/lim.; seat: front; flight hours: 980 total, 58 in this make and model, 931 as pilot in command, 58 in the last 90 days, 26 in the last 30 days

## Weather

- Conditions: Visual (VMC), Day
- Wind: 170° at 4 knots
- Visibility: 30 statute miles
- Lowest ceiling: 20,000 ft broken
- Temperature: 50 °F, dew point 36 °F
- Altimeter: 30.00 inHg

## 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 19900513060649A](https://openairdocs.org/incident/19900513060649A), May 13, 1990: Arctic S1B2, Talkeetna, AK, Substantial damage. Flying low scouting prey for hunter onboard. Engine quit. Crashed. Aircraft sat extended time. Varnish in fuel.

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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