# NTSB ANC90LA103: De Havilland DHC-3, N17689, Beaver Village, AK, June 30, 1990

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Limited investigation · Final report
- Date: June 30, 1990, 11:30 local (19:30 UTC)
- Place: Beaver Village, AK
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Minor injuries
- Injuries: 1 minor, 8 uninjured
- Status: Completed, report October 20, 1992
- Report: Approved by Office Director
- NTSB office: Alaska Regional Office
- NTSB case key (mKey): 5393
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC90LA103
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/5393/pdf
- Page: https://openairdocs.org/ntsb/ANC90LA103

## Probable cause

MECHANICAL FAILURE OF AN EXHAUST ROCKER ARM.

## Sequence of events

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

- Loss of engine power(partial) - mech failure/malf, cruise - normal
  - engine assembly,rocker arm/tappet - fractured (cause)
- Forced landing, descent - emergency
- In flight collision with terrain/water, landing
  - object - tree(s)

## Analysis

THE PILOT REPORTED A SUBSTANTIAL LOSS OF POWER WHILE IN CRUISE FLIGHT. HE WAS UNABLE TO MAINTAIN ALTITUDE AND THE AIRCRAFT CRASHED INTO TREES. AN EXAMINATION OF THE RECENTLY OVERHAULED ENGINE REVEALED A FRACTURED EXHAUST ROCKER ARM THAT CAUSED THE LOSS OF POWER.

## Aircraft

- Registration: [N17689](https://openairdocs.org/aircraft/N17689), registered now, S/N 431, built 1961 (OpenAirDocs)
- Reported make and model: DE HAVILLAND DHC-3
- Registry model: [Dehavilland DHC-3](https://openairdocs.org/model/dehavilland-dhc-3) (registry code 2800202) (OpenAirDocs)
- Registry engine: [Pratt & Whitney R1340 series](https://openairdocs.org/engine/pratt-whitney-r1340-series) (registry code 52016, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 431
- Airframe hours: 7111
- Engines: P&W R-1340 600 horsepower reciprocating
- Damage: Substantial damage
- Flight: Part 135
- Registered owner: Wright Air Service
- Airworthiness certificate: Standard, Normal
- Last inspection: 100 hour, June 27, 1990, 9 hours before
- Departed: FAI, FAIRBANKS, AK
- Destination: ARC, ARCTIC VILLAGE, AK
- Flight plan: VFR
- Airport: NONE

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 38; airline transport; airplane ratings: single-engine land, single-engine sea, multi-engine land; instrument ratings: airplane; medical: class 1, valid medical--w/ waivers/lim; seat: left; flight hours: 8,400 total, 165 in this make and model, 8,200 as pilot in command, 20 in the last 90 days, 15 in the last 30 days, 10 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 70° at 8 knots
- Visibility: 50 statute miles
- Lowest ceiling: none
- Temperature: 70 °F

## 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 19900630023029A](https://openairdocs.org/incident/19900630023029A), Jun 30, 1990: Dhav DHC3, Beaver Village, AK, Substantial damage. Engine failed en route, crash landed in trees. Rocker arm shaft bushing area had failed in fatigue. Recent overhaul

## Other investigations on N17689 (1)

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.

- [NTSB ANC89LA156](https://openairdocs.org/ntsb/ANC89LA156), Sep 2, 1989: de Havilland DHC-3 (N17689), Sheenjek River, AK, substantial damage. Probable cause: FAILURE OF THE PILOT TO GO AROUND WHEN HE WAS UNABLE TO ATTAIN THE PROPER TOUCHDOWN POINT AND HIS EXCESSIVE APPLICATION OF BRAKES DURING THE LANDING. CONTRIBUTING FACTORS WERE: THE DOWNDRAFT,…

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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