What happened
Shortly after takeoff, while maintaining an altitude of approximately 100 feet, the engine began to sputter and lose power, according to witnesses. The aircraft was observed banking steeply to the left before descending into a group of trees. A fire erupted at the site following the impact.
The investigation
Investigators examined the engine and found that the No. 3 connecting rod had failed due to fatigue. This fatigue originated within galling marks located in the bearing area on the crankshaft end. While manufacturer data from Lycoming Engines indicates that galling is typically caused by engine overspeed or overboost, no records were found indicating such events had occurred during this flight.
Following the separation of the No. 3 rod, the component jammed into the engine case; however, this did not prevent the engine from continuing to rotate. The propeller exhibited rotational damage, and the blade angle at the time of impact was measured in the 2100 RPM range. Additionally, several large tree limbs at the crash site showed evidence of being cut by the propeller.