On September 9, 2003, about 1200 Hawaiian standard time, an Eurocopter AS 350 BA helicopter, N5206J, collided with the ground during an uncontrolled descent while attempting to turn away from deteriorating weather conditions near Hilo, Hawaii. The helicopter, registered to and owned by Sunshine Helicopters, was being operated under the provisions of 14 CFR Part 135 as an air tour flight. The airline transport pilot and six passengers were uninjured; the helicopter sustained substantial damage. The flight departed Hapuna Heliport, Kamuela, Hawaii, at 1133, on a company visual flight rules (VFR) flight plan. A combination of visual meteorological conditions and instrument meteorological conditions prevailed during the flight. In a written statement, the operator reported that during the flight, the pilot was descending from 9,000 feet mean sea level (msl) through mountainous terrain when he encountered mist and low-level clouds being blown upslope from the east. A turn to the west was made, followed by a slight climb; however, he was unable to maintain a climb. The helicopter settled into terrain. No mechanical malfunctions were reported. Two passengers in the helicopter corresponded with the National Transportation Safety Board investigator-in-charge via email. The passengers stated that they were flying low over the terrain, viewing the lava flows in low visibility and foggy weather conditions. They were not sure why, but the pilot executed a turn. The ground was "getting closer and the helicopter started beeping." The pilot then said, "Oh my gosh," and the helicopter impacted the ground where it bounced across the rocky terrain for approximately 50 to 60 feet. At that point, the pilot was calling out ,"Mayday." The helicopter eventually impacted a pile of rocks, which created a hole in the bottom front window and broke the right skid off the helicopter. The pilot attempted to get the helicopter out of the rocks, but was unsuccessful. He was finally able to wedge it in the rocks upright, he shut the helicopter down, and the passengers got out. The pilot opined that the emergency crews would not be able to rescue them due to the poor weather conditions; as a result, the passengers inquired about an emergency kit. The emergency kit contained bandaids and a roll of gauze. A few hours later, a rescue helicopter was able to land and rescued the passengers and pilot.