On June 22, 2010, at 1430 Pacific daylight time, a Hughes 369HS helicopter, N8305F, was substantially damaged by fire subsequent to a precautionary landing near Paicines, California. The private pilot and his three passengers were not injured. Del Rio Aviation, Inc., was operating the helicopter under the provisions of 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed for the personal cross-country flight, which had originated from Paso Robles, California, approximately 1315. A flight plan had not been filed. The pilot reported that he had been airborne for a little over an hour and was at an altitude of 3,000 feet, and cruising at 100 knots on a 335-degree course. The pilot stated that he smelled smoke and felt a "different" vibration. The pilot immediately made a precautionary landing in a parking lot. As he and his passengers were exiting the helicopter, the pilot noted a fire. The pilot was unable to put the fire out with a fire extinguisher and the helicopter was subsequently consumed. Due to the extensive thermal damage, postaccident examination of the helicopter by two Federal Aviation Administration inspectors could not determine the source of the fire.