ANC97LA112 · Cessna 206
Cessna 206 · Accident: total loss of engine power (mechanical failure) en route
From Anchorage, AK to an unrecorded destination
Event
- NTSB case
- ANC97LA112
- 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
- Visual Meteorological Cond
Cessna 206
- Aircraft type
- Cessna 206
- 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
- N9412Z
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Anchorage, AKTo 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
- 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
- Total loss of engine power (mechanical failure)
- 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, crankshaft › Fatigue
- Other maintenance personnel › Maintenance, replacement, inadequate
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
While in cruise flight at 3,000 feet MSL over remote terrain, the engine suddenly quit. The pilot selected a flat area for an emergency landing. After touchdown, the float assemblies were torn off the fuselage, and the airplane nosed over. During the postaccident examination of the engine, one cylinder bolt was found loose, and the engine case displayed evidence of fretting. The crankshaft was broken. A metallurgical examination of the crankshaft revealed a fracture pattern typical of fatigue cracking. The number one engine cylinder had been replaced about 585 service hours before the accident.
Probable cause
A fatigue failure of the engine crankshaft, and an inadequate engine cylinder replacement by maintenance personnel. A factor in the accident was unsuitable terrain for a forced landing.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record ANC97LA112
- Event ID
- 20001208X08285
- Case number
- ANC97LA112
- 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 1997-07-26.
- API snapshot SHA-256: 4f02828c78e298f252fd3fe097c6272ed42ba9d05ab13a6aabc50cd92ef19e91; retrieved 2026-09-21T11:56:47.564Z.