Probable cause
The partial loss of engine power due to an improperly installed sparkplug.
NTSB analysis
Approximately 3 minutes after departure, at an altitude of 1,500 ft, the airplane’s engine experienced a partial loss of power, and the pilot initiated a return to the airport. During the landing roll, the airplane bounced, veered off the runway, and ground looped.
A postaccident examination of the airplane revealed the No. 2 cylinder bottom spark plug was laying loose in the engine compartment with the ignition lead still attached. The spark plug threads and corresponding threads in the cylinder displayed no signs of damage, which was consistent with the improper installation of the spark plug.
The engine was repaired about 11 months before the accident, which is likely when the spark plug was improperly installed. The airplane accumulated approximately 8 hours since the maintenance.
Text from the NTSB. Open the NTSB docket for WPR21LA071 for the full record.
Event
- Date
- Nov 17, 2020
- Type
- Accident
- Place
- Compton, California
- Nearest airport
- Compton/Woodley (CPM)
- Highest injury
- Minor
- Minor injuries
- 1
- Weather
- Visual (VMC)
- Light
- Day
Amateur-built COZY
- N-number
- N82V
- Category
- Airplane
- Year built
- 2004
- 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.