Probable cause
A total loss of engine power due to the fatigue failure of a retaining circlip in one of the No. 2 crankshaft cheek counterweights, which resulted in liberation of the counterweight.
NTSB analysis
The pilot reported that he was about 15 minutes into the cross-country flight when the engine made a “loud bang,” began to run rough, and eventually seized. Unable to glide to an open field, the pilot conducted a forced landing into trees. He and his passenger were not injured; however, the airplane was substantially damaged.
Examination revealed several holes in the engine case, and one of the No. 2 crankshaft cheek counterweights was missing. Further examination revealed two of the counterweight retaining circlips were fractured. Examination of the fractured circlips revealed that one of the circlip legs failed from fatigue crack propagation. The engine had been disassembled and the crankshaft inspected due to a propeller strike about 130 operating hours before the accident.
Text from the NTSB. Open the NTSB docket for ERA23LA361 for the full record.
Event
- Date
- Sep 2, 2023
- Type
- Accident
- Place
- Rutledge, Tennessee
- Highest injury
- None
- Weather
- Visual (VMC)
- Light
- Day
Beech V35
- N-number
- N5431U
- Category
- Airplane
- Year built
- 1967
- Damage
- Substantial
- Operating rule
- Part 91 (general aviation)
- Purpose of flight
- Personal
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.