# NTSB SEA90FA171: Lake LA-4, N68DG, Onalaska, WA, June 9, 1990

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Field investigation · Final report
- Date: June 9, 1990, 13:30 local (20:30 UTC)
- Place: Onalaska, WA
- Coordinates: 46.599651, -122.66996 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=46.5997&lon=-122.6700&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 3 fatal
- Status: Completed, report September 5, 1991
- Report: Approved by Office Director
- NTSB case key (mKey): 41126
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA90FA171
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/41126/pdf
- Page: https://openairdocs.org/ntsb/SEA90FA171

## Probable cause

IMPROPER IN-FLIGHT PLANNING/DECISION BY THE PILOT, AND HIS INADVERTENT FLIGHT INTO INSTRUMENT METEOROLOGICAL CONDITIONS (IMC).  FACTORS RELATED TO THE ACCIDENT WERE: THE ADVERSE WEATHER AND TERRAIN CONDITIONS.

## Sequence of events

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

- In flight encounter with weather, cruise
  - in-flight planning/decision - improper, pilot in command (cause)
  - terrain condition - high terrain (contributing factor)
  - terrain condition - blind/box canyon (contributing factor)
  - terrain condition - rising (contributing factor)
  - weather condition - clouds (contributing factor)
  - weather condition - low ceiling (contributing factor)
  - vfr flight into imc - inadvertent, pilot in command (cause)
- In flight collision with terrain/water, maneuvering
  - terrain condition - mountainous/hilly (contributing factor)

## Analysis

BEFORE DEPG ON A FLT FROM NEWPORT, OR, TO RENTON WA, THE PLT OBTAINED A WX BRIEFING. HE WAS ADZD THAT THE WX WAS MARGINAL VFR & FORECAST TO BE VARIABLE IMC ALONG THE ROUTE. HE DID NOT DECLARE HIS INTENTIONS OR FILE A FLT PLAN, BUT TOOK OFF ABOUT 2 HRS LATER. WHEN THE ACFT DID NOT ARRIVE, A SEARCH WAS MADE. IT WAS NOT FOUND UNTIL 8/24/90. THE PLANE HAD CRASHED ON WOODED/MOUTAINOUS TERRAIN, NEAR THE HEAD OF A CANYON AT AN ELEV OF ABOUT 1800'. IMPACT OCCURRED ON A HEADING OF 165 DEG; ENTRANCE TO THE CANYON WAS SOUTH OF THE CRASH SITE. NO PREIMPACT PART FAILURE OR MALFUNCTION OF THE ACFT OR ENG WAS FOUND. APRX 16 MI SSW AT TOLEDO (ELEV 371'), THE 1345 PDT WX WAS IN PART: 1200' OVC, 8 MI VIS WITH LIGHT RAIN, WIND FROM 330 DEG AT 9 KTS.

## Aircraft

- Registration: [N68DG](https://openairdocs.org/deregistered/N68DG-1991-06-21), registration cancelled 1991-06-21, S/N 382 (OpenAirDocs)
- Reported make and model: LAKE LA-4
- Registry model: [Lake LA-4](https://openairdocs.org/model/lake-la-4) (registry code 5110302) (OpenAirDocs)
- Category: Airplane
- Serial number: 382
- Airframe hours: 1196
- Engines: LYCOMING O-360-A1A 180 horsepower reciprocating
- Damage: Destroyed
- Flight: Personal, Part 91
- Registered owner: Walter D. Gaines
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, June 1, 1989, 77 hours before
- Departed: ONP, NEWPORT, OR
- Destination: RNT, RENTON, WA

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 51; airline transport; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 3, valid medical--w/ waivers/lim; seat: left; flight hours: 7,000 total

## Weather

- Conditions: Instrument (IMC), Day
- Wind: 330° at 9 knots
- Temperature: 55 °F, dew point 52 °F
- Altimeter: 29.00 inHg
- Observed at: T09, 16 nm away

## 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 19900609042269A](https://openairdocs.org/incident/19900609042269A), Jun 9, 1990: Conaer LA4, Onalaska, WA, Destroyed, 3 fatal. Struck trees on cloud obscured mountain slope. Was observed flying low under clouds. Weather brief marginal VFR.

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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