Probable cause
The pilot's improper installation of the propeller bolts, which resulted in the in-flight separation of the propeller.
NTSB analysis
The pilot departed on a local flight during which the airplane experienced an in-flight separation of the propeller. The pilot then performed a forced landing to a field that resulted in substantial damage to the fuselage. Postaccident examination of the airplane revealed that the pilot installed the propeller bolts backwards. The bolts were also found to be improperly torqued.
Text from the NTSB. Open the NTSB docket for CEN12LA539 for the full record.
Event
- Date
- Aug 11, 2012
- Type
- Accident
- Place
- Burlington, Wisconsin
- Highest injury
- Minor
- Minor injuries
- 2
- Weather
- Visual (VMC)
- Light
- Day
Amateur-built MATHES
- N-number
- N31TM
- Category
- Airplane
- 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.