Probable cause
The failure of the engine’s No. 1 piston connecting rod retaining bolts due to fatigue, which resulted in a total loss of engine power during cruise flight.
NTSB analysis
While in level cruise on the scheduled passenger flight, the airline transport pilot heard a loud "bang," followed by a quieter "bang" and a total loss of engine power. He conducted a forced landing to a densely-wooded area, during which the airplane nosed over, resulting in substantial damage to the wings and horizontal stabilizer. A visual examination of the engine revealed a crack in the crankcase. A subsequent examination of the No. 1 piston assembly revealed fatigue fractures in both connecting rod retaining bolts. Additional internal damage to the engine was found to be consistent with damage caused by the release of the connecting rod from the crankcase.
Text from the NTSB. Open the NTSB docket for ANC14LA040 for the full record.
Event
- Date
- Jun 9, 2014
- Type
- Accident
- Place
- Chitina, Alaska
- Highest injury
- None
- Weather
- Visual (VMC)
- Light
- Day
Cessna U206C
- N-number
- N29137
- Category
- Airplane
- Year built
- 1968
- Damage
- Substantial
- Operating rule
- Part 135 (charter and commuter)
From the NTSB aviation accident database: N-registered aircraft, events since 2008, data through Oct 28, 2026. The file is published monthly, so the latest weeks are incomplete and recent records can change. The official source is the NTSB aviation investigation search. CheckAero is independent and not affiliated with the NTSB.