Probable cause
A partial loss of engine power due to the fatigue fracture of the No. 4 exhaust valve.
NTSB analysis
According to the pilot, while conducting a local flight, he heard a "pop" followed by a partial loss of engine power. The airframe started shaking badly, he pulled power to idle, established best glide, and contacted Air Traffic Control (ATC). ATC provided alternate airports and current weather information. Unable to maintain altitude, he initiated a forced landing to a clearing on the beach. During the landing roll, the airplane impacted a rock retaining wall, which resulted in substantial damage to the fuselage and left horizontal stabilizer.
Examination of the engine revealed that the No. 4 exhaust valve was fractured. Metallurgical examination of the fracture surfaces on the exhaust valve revealed that it had fractured due to fatigue. The fatigue fracture of the No. 4 exhaust valve likely led to the partial loss of engine power.
Text from the NTSB. Open the NTSB docket for WPR22LA351 for the full record.
Event
- Date
- Sep 16, 2022
- Type
- Accident
- Place
- Ventura, California
- Nearest airport
- (NA)
- Highest injury
- Minor
- Minor injuries
- 2
- Weather
- Visual (VMC)
- Light
- Day
Cessna 172L
- N-number
- N7917G
- Category
- Airplane
- Year built
- 1970
- 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.