SEA93FA091 · Lake LA-4-200
Lake LA-4-200 · Accident: loss of control in flight while maneuvering
From Lake Stevens, WA to an unrecorded destination
Event
- NTSB case
- SEA93FA091
- 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
- 4 · 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
- Visual Meteorological Cond
Lake LA-4-200
- 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
- N39375
- Operator
- Helgeson, Robert C. · private individual
- Onboard fatalities
- Unknown
- Route
- From Lake Stevens, WATo not recorded
- 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
- Maneuvering
- 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
- Loss of control in flight
- 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
- Stall
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Substantial
Cause areas
- Pilot in command › Airspeed, not maintained
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
THE AIRPLANE WAS FOUND SUBMERGED IN 40 FT OF WATER AND APPROXIMATELY 40 FT FROM SHORE ON THE NE END OF LAKE ISABEL. IMPACT DAMAGE WAS INDICATIVE OF A NEAR-VERTICAL NOSE-DOWN ATTITUDE AT IMPACT. THE MOUNTAINOUS TERRAIN RISES RAPIDLY ON ALL SIDES OF THE LAKE, AND THE LAKE NARROWS TO APPROXIMATELY 530 FT WIDE AT THE NE END. THE PILOT'S FLIGHT INSTRUCTOR STATED THAT THE PILOT HAD BEEN TAUGHT TO CIRCLE THE LAKE A FEW TIMES BEFORE LANDING TO ASSESS THE WATER CONDITIONS.
Probable cause
THE PILOT'S FAILURE TO MAINTAIN ADEQUATE AIRSPEED WHILE MANEUVERING FOR A WATER LANDING.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record SEA93FA091
- Event ID
- 20001211X12241
- Case number
- SEA93FA091
- 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: 085fad458a190baebe4432ebbb4571d2ebca502c058e296b0981014e4ca7577b; retrieved 2026-09-21T00:38:53.745Z.