SEA97LA193 · Cessna TU206G
Cessna TU206G · Accident: total loss of engine power (mechanical failure) en route
From Felts Field (SFF) to Grant County International Airport (MWH)
Event
- NTSB case
- SEA97LA193
- 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 TU206G
- 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
- N6620Z
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Felts Field (SFF), Spokane, WATo Grant County International Airport (MWH), Moses Lake, WA
- 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 · climb to 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
- Engine assembly, crankshaft › Fractured
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The private pilot stated that during climb, about 10 minutes after takeoff, he felt a strong vibration in the engine, followed by an abrupt engine stoppage a few seconds later. During the subsequent forced landing onto rolling terrain that was surrounded by obstructions, the airplane struck a fence post, hit a ditch, and flipped over. An examination of the engine revealed that the crankshaft had fractured. The fracture was the result of fatigue cracking that initiated at the surface of the aft radius of the no. 2 main bearing journal. Heavy rubbing damage in the aft radius indicated that the bearing shifted aft and scored the radius resulting in fatigue initiation at the surface. A visual inspection of the crankcase mating surfaces revealed fretting, indicating that there was relative motion between the two crankcase halves. No evidence of heat distress or lack of lubrication was found. The engine, a Continental TSIO-520, had received a 'top' overhaul about 45 operating hours before the accident.
Probable cause
A fatigue failure of the engine crankshaft. Factors contributing to the accident were the rolling terrain, and the fence.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record SEA97LA193
- Event ID
- 20001208X08752
- Case number
- SEA97LA193
- 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: 2b148d28f35593e3e22a1a754f979314cd6f6e8d7fc74cf4caab6c33627c5c48; retrieved 2026-09-22T18:48:07.242Z.