Probable cause
A total loss of engine power due to the failure of the No. 2 cylinder exhaust valve for reasons that could not be determined.
NTSB analysis
While in cruise flight, the airplane’s engine began to run rough. As the pilot was attempting to restore engine power, the engine experienced a total loss of engine power. The pilot performed a forced landing to a field and the airplane collided with terrain.
A postaccident examination of the engine revealed that the No. 2 cylinder exhaust valve had failed, damaging the piston head and resulting in a loss of engine power. Machining of the fracture surfaces precluded determining the mode of failure. The engine was last overhauled about 32 years before the accident with just over 1,030 hours logged on the components. The engine manufacturer recommends an overhaul every 1,800 hours or 12 years.
Text from the NTSB. Open the NTSB docket for CEN21LA408 for the full record.
Event
- Date
- Aug 15, 2021
- Type
- Accident
- Place
- Heavener, Oklahoma
- Nearest airport
- (n/a)
- Highest injury
- Minor
- Minor injuries
- 1
- Weather
- Visual (VMC)
- Light
- Day
Cessna 150
- N-number
- N50055
- Category
- Airplane
- Year built
- 1968
- 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.