Arctic Circle Air Service Flight 40
Cessna 206 · Accident: total loss of engine power (mechanical failure) en route
From Bethel Airport (BET) to Chevak Airport (VAK)
Event
- NTSB case
- ANC95LA058
- 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
- Charter & commuter
- 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
- N19BR
- Operator
- Arctic Circle Air Service
- Onboard fatalities
- Unknown
- Route
- From Bethel Airport (BET), AKTo Chevak Airport (VAK), Chevak, 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 135: Air Taxi & Commuter
- 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, bearing › Failure, total
- Engine assembly, crankshaft › Fatigue
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
THE COMMERCIAL PILOT DEPARTED ON AN AIR TAXI CARGO FLIGHT TO A REMOTE DESTINATION. ABOUT 20 MINUTES AFTER TAKEOFF, THE ENGINE SUDDENLY QUIT, AND THE PILOT PERFORMED AN EMERGENCY LANDING ON ROUGH TERRAIN IN A STREAM BED. AFTER RECOVERY OF THE AIRPLANE 5 MONTHS LATER, AN EXAMINATION OF THE ENGINE REVEALED THAT THE #2 MAIN BEARING HAD FAILED AND THE CRANKSHAFT HAD FRACTURED THROUGH THE CRANK CHEEK BETWEEN THE #2 ROD AND #2 MAIN BEARING JOURNALS. THE #2 MAIN BEARING WAS SEVERELY FRAGMENTED AND DEFORMED, AND THE NUMBER 2 MAIN BEARING SADDLE WAS SEVERELY DEFORMED. A METALLURGICAL EXAMINATION OF THE CRANKSHAFT INDICATED THAT IT HAD FAILED FROM FATIGUE. THE EXAMINATION ALSO DISCLOSED THAT THE CRANKSHAFT CONFORMED TO THE MANUFACTURER'S MATERIAL SPECIFICATIONS FOR HARDNESS AND NITRIDING. RECORDS SHOWED THE ENGINE HAD BEEN REBUILT BY THE MANUFACTURER ON 7/23/92 AND INSTALLED IN THE AIRPLANE ON 9/3/92. AFTER BEING REBUILT, IT HAD ACCUMULATED 1154 HOURS OF FLIGHT TIME. AT 1004 HOURS, THE OIL PUMP HAD BEEN SERVICED DUE TO LOW OIL PRESSURE. DURING A 100 HOUR INSPECTION AT 1140 HOURS, METAL WAS FOUND IN THE OIL FILTER AND THE #4 CYLINDER WAS CHANGED.
Probable cause
A FAILURE OF THE #2 MAIN ENGINE BEARING AND SUBSEQUENT FATIGUE FAILURE OF THE ENGINE CRANKSHAFT. A FACTOR RELATING TO THE ACCIDENT WAS: THE LACK OF SUITABLE TERRAIN FOR AN EMERGENCY LANDING.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record ANC95LA058
- Event ID
- 20001207X03399
- Case number
- ANC95LA058
- 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: fe43d70e42b25b75bb4c323a6af8d1905c3ce1e98e3e82918d4919801b5cdd2b; retrieved 2026-09-18T18:00:36.946Z.