ANC89LA171 · Helio H-250
Helio H-250 · Accident: in flight encounter with weather en route
From TAYLOR MTN, AK to Iliamna Airport (ILI)
Event
- NTSB case
- ANC89LA171
- 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
- 0 · 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
Helio H-250
- Aircraft type
- Helio H-250
- 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
- N5450E
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From TAYLOR MTN, AKTo Iliamna Airport (ILI), ILIAMNA, AK
- 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
- Substantial
Cause areas
- Pilot in command › Preflight planning/preparation, inadequate
- Pilot in command › VFR flight into imc, continued
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
THE PLT DID NOT RECEIVE A WX BRIEFING FOR THE RETURN FLT, BECAUSE HE HAD JUST FLOWN OVER THE AREA. DURING THE RETURN FLT, HE ENCOUNTERED OBSCURED CEILINGS, REDUCED VISIBILITIES, HEAVY RAIN, FREEZING RAIN, & SEVERE TURBULENCE. ACCORDING TO THE PLT, THE ACFT SUBSEQUENTLY LANDED IN A SWAMP & CREEK AT NIGHT. HE STATED HE HAD SLOWED THE ACFT TO 25 TO 30 KTS, WHEN THE ACFT MADE CONTACT WITH THE GROUND. THE AIRPLANE SLID APRX 40 FT TO A STOP. THE FLT VISIBILITY WAS RPRTD TO BE ZERO, WHEN THE ACFT CONTACTED THE GROUND.
Probable cause
INADEQUATE PREFLIGHT PLANNING/PREPARATION BY THE PILOT AND HIS CONTINUED FLIGHT INTO INSTRUMENT METEOROLOGICAL CONDITIONS (IMC). FACTORS RELATED TO THE ACCIDENT WERE: DARKNESS AND ADVERSE WEATHER CONDITIONS.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record ANC89LA171
- Event ID
- 20001213X29280
- Case number
- ANC89LA171
- 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: local date, investigation status. Values present in the bulk record are kept.
- The date is the local date; the NTSB stores the UTC date 1989-09-21.
- API snapshot SHA-256: 48fdb8986e51ff60d02e1fb7e36fd17b922f2f6ee5f7829ba17483546c667882; retrieved 2026-09-22T00:02:10.186Z.