What happened
The aircraft was observed decelerating significantly while flying over a parking area. It then proceeded toward an adjacent body of water. Witnesses reported seeing a puff of smoke emanating from the rear section of the engine compartment. As the helicopter approached the water, it exhibited unstable flight characteristics, fishtailing as it nearly lost forward momentum before descending vertically into the lake nose-first. The aircraft sank almost immediately upon impact.
The investigation
Post-accident examination of the airframe revealed a distinct hole in the engine crankcase. Analysis of the fracture surfaces suggested an internal puncture that breached the external casing. Further inspection identified a fatigue failure of a connecting rod cap bolt, which led to the separation of the rod from the crankshaft. This mechanical failure resulted in extensive damage to the internal components of the engine.
Findings
The pilot was identified as having low flight time and reported an inability to swim, along with a fear of water. These personal factors were noted in the context of the accident outcome.