ANC04LA059 · Piper PA-31-350
Piper PA-31-350 · Accident: in flight encounter with weather en route
From Goodnews Airport (GNU) to Bethel Airport (PABE)
Event
- NTSB case
- ANC04LA059
- 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
- Unknown
- 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
Piper PA-31-350
- Aircraft type
- Piper PA-31
- 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
- N4105D
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Goodnews Airport (GNU), Goodnews, AKTo Bethel Airport (PABE), Bethel, 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
- 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 › Design stress limits of aircraft, exceeded
- Pilot in command › Weather evaluation, inadequate
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
The airline transport certificated pilot departed a remote airport in a twin-engine airplane. The airport is located on the coast of the Bering Sea, and has an area of low hills that are northwest of the airport. The pilot said the wind conditions were about 070 degrees magnetic at 25 knots, with gusts to 30 knots. After departure, the pilot reported that he initially climbed the airplane to about 1,200 feet, but as he approached the area of low hills, he descended to about 700 feet. At an indicated airspeed of about 185 knots, the pilot said that the airplane encountered severe turbulence for about 30 seconds, during which his radio headset was dislodged. Upon arrival at his destination, the pilot informed the director of maintenance that during the flight, the airplane encountered turbulence and appeared to have received damage to the wings. The director of maintenance reported that the airplane received structural damage that consisted of wrinkling and rippling of both of the upper wing surfaces, extending about 8 feet outboard from each engine nacelle. In addition, the elevator had wrinkling that extended about 6 inches inboard from each of the outboard hinge attach points. The closest official weather observation station is located about 32 nautical miles south of the accident site. An automated weather observation system (AWOS) was reporting in part: Wind, 110 degrees (true) at 17 knots, gusts to 27 knots; visibility, 7 statute miles; clouds and sky condition, 1,200 feet overcast.
Probable cause
The pilot's inadequate weather evaluation which resulted in an in-flight encounter with severe turbulence, and his exceedence of the design stress limits resulting in overstress of the wings. A factor contributing to the accident was the presence of turbulence.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record ANC04LA059
- Event ID
- 20040604X00738
- Case number
- ANC04LA059
- 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, coordinates. Values present in the bulk record are kept.
- The date is the local date; the NTSB stores the UTC date 2004-05-23.
- API snapshot SHA-256: 445fe54810868928d6ec848108ade530808710b1e9b1b51cfa2cb3e290f36065; retrieved 2026-09-22T07:29:19.171Z.