SEA90FA171 · Lake LA-4
Lake LA-4 · Accident: in flight encounter with weather en route
From Newport Municipal Airport (ONP) to Renton Municipal Airport (RNT)
Event
- NTSB case
- SEA90FA171
- Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
- Accident
- InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
- Completed
- API-reported fatalities
- 3 · all aircraft and ground
- Ground fatalities
- 0
- OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
- General aviation
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Instrument Meteorological Cond
Lake LA-4
- Aircraft type
- Lake LA-4
- Category
- Airplane
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- N68DG
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Newport Municipal Airport (ONP), Newport, ORTo Renton Municipal Airport (RNT), Renton, WA
- Aircraft age
- Not recorded
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Part 91: General Aviation
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- En route · cruise
- First occurrenceThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- In flight encounter with weather
- Also codedOther events the NTSB coded in the sequence, such as a wire strike after a loss of power. Flight Findings uses them for its kinds of event. Glossary
- Visual flight rules (VFR) flight into instrument meteorological conditions (IMC)
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Destroyed
Cause areas
- Pilot in command › In-flight planning/decision, improper
- Pilot in command › VFR flight into imc, inadvertent
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
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.
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.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record SEA90FA171
- Event ID
- 20001212X23538
- Case number
- SEA90FA171
- Dataset
- historical-pre2008
- Source SHA-256
- 89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
Source notes (4)
- Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
- Filled from the NTSB case API where the bulk record had no value: investigation status. Values present in the bulk record are kept.
- The date is the local date, which is the same as the UTC date the NTSB stores.
- API snapshot SHA-256: 0d9504f4f6a437545eeddd9af02481ccc48c7425bf0a6259e65218a457c42a9b; retrieved 2026-09-21T02:35:52.977Z.