The helicopter sustained substantial damage during a forced landing after a total loss of engine power during cruise flight. The helicopter was recently purchased by the left seat pilot, who did not hold a rotorcraft rating, and was being piloted by the right sear pilot at the time of the accident. The right seat pilot stated that he performed an autorotation on a hilltop, which was "sparsely populated" by 7-1/2 to 8 foot high trees. He also stated that the hilltop was the only available landing area, which was surrounded by "hostile" terrain. During the forced landing, the tail boom sustained damage on impact with trees. Examination of the helicopter revealed no usable fuel aboard.