What happened
The incident occurred while the aircraft was conducting a swath run. During this phase of flight, the engine began running roughly and failed to produce sufficient power to sustain level flight. Recognizing the imminent loss of control, the pilot elected to execute a forced landing in an adjacent field that had been freshly plowed. The soft and uneven terrain contributed to the aircraft nosing over upon impact.
The investigation
Following the accident, investigators conducted a detailed inspection of the airframe and engine components. The examination revealed a critical mechanical failure within the ignition system. Specifically, one of the magnetos was found to have teeth missing from its drive gear. This damage prevented the magneto from functioning correctly, causing the ignition timing to be significantly off.
Findings
The primary factor leading to the accident was the loss of engine power due to the faulty magneto. The magneto drive gear had sustained damage that disrupted the ignition sequence. This mechanical failure directly resulted in the rough running and subsequent inability to maintain altitude, necessitating the emergency landing. The nose-over was a consequence of the landing surface conditions rather than a structural failure of the aircraft itself.
Safety message
Regular pre-flight inspections are critical for identifying potential ignition system issues before they lead to in-flight emergencies. Ensuring that all magneto components are intact and functioning properly can prevent sudden power loss during flight operations.