Probable cause
The reciprocating engine's exhaust valve being stuck in the “open” position, which resulted in a partial loss of engine power during initial climb.
NTSB analysis
The student pilot and flight instructor were conducting a personal flight. The flight instructor reported that the pretakeoff checks were "normal" but that, during the takeoff, the engine felt "weak" and that the engine lost power during the initial climb. The flight instructor conducted a forced landing to a field, during which the airplane impacted the top of a tree and then the ground.
Examination of the airplane revealed that the exhaust valve for the No. 4 cylinder was stuck in the "open" position possibly due to excessive deposits from the combustion process. It is likely that the stuck exhaust valve resulted in the partial loss of engine power reported by the flight instructor.
Text from the NTSB. Open the NTSB docket for CEN17LA093 for the full record.
Event
- Date
- Jan 30, 2017
- Type
- Accident
- Place
- Brenham, Texas
- Nearest airport
- Brenham Muni (11R)
- Highest injury
- None
- Weather
- Visual (VMC)
- Light
- Day
Piper J3C
- N-number
- N7039H
- 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.