What happened
The pilot was conducting a flight that included a climbout phase when an unexpected loss of engine power occurred. Unable to maintain altitude or return to the departure airport, the pilot executed a forced landing in a nearby plowed field. The impact forces caused the aircraft to nosed over upon touchdown.
The investigation
A detailed examination of the wreckage was conducted to determine the mechanical cause of the power loss. Investigators discovered that the seal on the carburetor airbox had significantly deteriorated. This degraded material had broken loose and lodged itself in the throat of the carburetor, obstructing airflow and fuel delivery.
Findings
Maintenance records indicated that the last annual inspection was completed 96 flight hours prior to the accident. The deterioration of the carburetor airbox seal appears to have been a latent defect not addressed during the previous maintenance cycle. The obstruction caused by the deteriorated material led directly to fuel exhaustion or engine flameout, resulting in the loss of power during a critical phase of flight.
Safety message
This incident highlights the importance of thorough inspections for aging components within the induction system. Regular checks should specifically look for signs of seal degradation that could potentially detach and cause blockages.