# NTSB ANC90LA098: De Havilland DHC-2, N5147G, Caribou Lake, AK, June 27, 1990

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: June 27, 1990, 13:30 local (21:30 UTC)
- Place: Caribou Lake, AK
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 3 uninjured
- Status: Completed, report February 12, 1993
- Report: Approved by Office Director
- NTSB office: Alaska Regional Office
- NTSB case key (mKey): 5389
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC90LA098
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/5389/pdf
- Page: https://openairdocs.org/ntsb/ANC90LA098

## Probable cause

A POWER LOSS CAUSED BY THE FAILURE OF A PISTON CYLINDER.

## 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
  - engine assembly,cylinder - separation (cause)
- Forced landing, descent - emergency
- In flight collision with object, approach - vfr pattern - final approach
  - object - tree(s)

## Analysis

THE PILOT REPORTED A COMPLETE LOSS OF POWER SHORTLY AFTER TAKEOFF FROM CARIBOU LAKE. HE SAID THAT HE MADE A CONTROLLED LANDING INTO SMALL SPRUCE TREES, CAUSING SUBSTANTIAL DAMAGE TO THE AIRPLANE. A SUBSEQUENT INSPECTION OF THE AIRPLANE'S ENGINE REVEALED THAT THE NUMBER NINE CYLINDER HAD SEPARATED, CAUSING THE LOSS OF POWER.

## Aircraft

- Registration: [N5147G](https://openairdocs.org/aircraft/N5147G), registered now, S/N 350, built 1951 (OpenAirDocs)
- Reported make and model: DE HAVILLAND DHC-2
- Registry model: [Dehavilland BEAVER DHC-2 MK.1](https://openairdocs.org/model/dehavilland-beaver-dhc-2-mk-1) (registry code 2800102) (OpenAirDocs)
- Registry engine: [Pratt & Whitney R-985 series](https://openairdocs.org/engine/pratt-whitney-r-985-series) (registry code 52008, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 350
- Airframe hours: 8228
- Engines: P&W R985AN4B 450 horsepower reciprocating
- Damage: Substantial damage
- Flight: Part 135
- Registered owner: Alfred M Lee
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, May 22, 1990, 47 hours before
- Flight plan: Company VFR
- Airport: NONE

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 65; commercial; airplane ratings: single-engine land, single-engine sea; medical: class 2, valid medical--w/ waivers/lim; seat: left; flight hours: 18,000 total, 1,000 in this make and model, 35 in the last 90 days, 35 in the last 30 days, 4 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 360° at 5 knots
- Visibility: 50 statute miles
- Lowest ceiling: 10,000 ft broken
- Temperature: 61 °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 19900627025209A](https://openairdocs.org/incident/19900627025209A), Jun 27, 1990: Dhav DHC2MK1, Caribou Lake, AK, Substantial damage. Lost power at power reduction after takeoff. Descended into trees onshore. Found a cracked cylinder.

## Other investigations on N5147G (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 ANC83LA158](https://openairdocs.org/ntsb/ANC83LA158), Sep 1, 1983: de Havilland DHC-2, MK-1 (N5147G), Barrow, AK, substantial damage

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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