On March 27, 1995, at 1700 hours Pacific standard time, a Robinson R-22B helicopter, N8320A, landed in soft soil and rolled over during a local instructional flight at Byron, California. The aircraft was substantially damaged and the two pilots were not injured. Visual meteorological conditions prevailed at the time. The flight originated at Concord, California, at 1640. Information from the operator, Helicopter Adventures, Inc., of Concord, indicated that the accident occurred when the aircraft skids sank in soft ground during a practice autorotation. The aircraft pitched forward until the blades struck the ground. The helicopter then rolled over on its right side. The pilot stated in his report that the area appeared suitable for touchdown; however, a dry crust was on the surface and the ground beneath was soft and wet. The pilot did not report any mechanical malfunctions.