Probable cause
A partial loss of engine power due to failure of the No. 1 cylinder intake valve head.
NTSB analysis
The pilot reported that while en route he noticed a loss of engine power and the oil pressure decreasing. He performed a forced landing to a road. During the landing rollout the right wingtip struck a sign, which resulted in substantial damage.
Postaccident examination of the engine revealed the No. 1 cylinder was fractured from the engine and remained partially attached by exhaust tubes and the intake manifold. The intake valve stem was fractured about an inch from the interior base of the valve. The piston and intake valve were destroyed by the internal forces in the engine and the fragments were not located.
Text from the NTSB. Open the NTSB docket for ANC23LA051 for the full record.
Event
- Date
- Jul 13, 2023
- Type
- Accident
- Place
- Ninilchik, Alaska
- Nearest airport
- Ninilchik (NIN)
- Highest injury
- None
- Weather
- Visual (VMC)
- Light
- Day
Stinson 108
- N-number
- N97719
- Category
- Airplane
- Year built
- 1946
- 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.