What happened
Shortly after takeoff, while climbing through approximately 130 feet AGL, the aircraft experienced a sudden loss of engine power. The pilot attempted to perform an emergency landing in a nearby open field. During this maneuver, the aircraft struck a power line and nosed over, eventually coming to rest inverted in the field. The pilot noted that the terrain surrounding the airfield was characterized by various obstacles and power lines.
The investigation
A post-accident examination of the engine identified that the center main crankshaft bearing had spun. Investigators also examined the mating surfaces around the bolt holes, as well as both halves of the engine block center main bearing caps, which revealed evidence of fretting. According to the engine manufacturer, improper torque applied to the main bearing through bolts is a condition that results in such fretting.
Findings
Maintenance records showed that the engine had undergone an overhaul in March 1989. At the time of the most recent annual inspection on August 21, 1995, the engine had accumulated 105 hours of use.