Sequence of Events
According to the pilot, while flying at 1,000 feet above ground level (AGL), the engine experienced a sudden loss of power and the collective became very heavy. After initiating an autorotation, the pilot observed a split between the rotor revolutions per minute (RPM) and the N2 needle. The pilot then decided to proceed toward a rock pit that had been spotted and continued the autorotation.
At approximately 60 knots and 30 feet AGL, just as the pilot pulled back on the cyclic to slow down, the helicopter impacted the ground with its left skid. The subsequent impact caused the helicopter to roll over onto its left side, during which the main rotor blades severed the tail boom, resulting in substantial damage.
Examination
A post-accident examination of the helicopter failed to reveal any anomalies that would have prevented normal operations.