What happened
The pilot reported that the aircraft engine began to run rough while the aircraft was at 4,500 feet mean sea level. Shortly thereafter, the engine lost power completely. In response to the emergency, the pilot attempted to execute a forced landing on a nearby roadway. During the approach, the aircraft struck trees before ultimately impacting the terrain adjacent to the road.
The investigation
A physical examination of the engine was conducted following the accident. The inspection revealed that the fuel injector diaphragm and its associated 'O' ring were leaking. This mechanical failure is identified as the primary reason for the loss of engine power.
Findings
The investigation determined that the fuel injector diaphragm leak was the critical factor leading to the accident. The sequence of events began with rough running, progressed to total power loss, and resulted in a collision with trees during the attempted emergency landing. No other mechanical anomalies were cited as contributing factors.
Safety message
Regular inspection of fuel system components, particularly diaphragms and seals, is essential to prevent in-flight engine failures. Pilots should be aware that rough running can precede total power loss and must be addressed immediately.