ANC05LA018 · Piper PA-28-140
Piper PA-28-140 · Accident: loss of engine power en route
From Lake Hood Airport (Z41) to Bethel Airport (BET)
Event
- NTSB case
- ANC05LA018
- 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-28-140
- Aircraft type
- Piper PA-28
- 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
- N801FS
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Lake Hood Airport (Z41), Anchorage, AKTo Bethel Airport (BET), 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
- Loss of engine power
- 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
- Engine assembly, valve, exhaust › Fractured
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
The commercial certificated pilot reported that while the airplane was in level cruise flight at 5,000 msl, he noted a rough running engine and a slight reduction in engine rpm, which was followed by a rapid loss of engine power, and subsequent loss of altitude. He was unable to restore adequate engine power to maintain level flight, and selected a snow-covered area as a forced landing site. During the landing roll, the airplane's nose landing gear collapsed, and the airplane nosed over. The airplane sustained structural damage to the wings and fuselage. An FAA inspector reported that during his inspection of the accident airplane's engine, he discovered that a significant portion of the exhaust valve had broken free from the exhaust valve stem in the number 1 cylinder. He stated that the broken portion of the valve subsequently entered the number 1 cylinder combustion chamber and damaged the piston.
Probable cause
A loss of engine power during cruise flight due to a fractured exhaust valve, which resulted in a forced landing, and subsequent nose over of the airplane. A factor associated with the accident was the lack of suitable terrain for a successful emergency landing.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record ANC05LA018
- Event ID
- 20050105X00017
- Case number
- ANC05LA018
- 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, coordinates. 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: 230c63b0e67eeaf01e93e1809fa085ab659a1fa99fecb870a919458feeb765da; retrieved 2026-09-21T19:05:57.934Z.