On December 27, 2003, about 1430 eastern standard time, a Schweizer 269C-1 helicopter, N358SS, was substantially damaged during a practice autorotation in Byron, New York. The certificated private pilot received serious injuries. Visual meteorological conditions prevailed for the local flight that departed from Genesee County Airport (GVQ), Batavia, New York. No flight plan had been filed for the local flight that was conducted under 14 CFR Part 91. The pilot reported that he flew to Le Roy Airport (5G0), and performed practice approaches. He then departed Le Roy Airport to the northwest, and looked for a field to practice autorotations. He further stated: "...I started the autorotation at 1,300 feet msl [600 feet agl]. At approx, 300 feet into the auto, I felt a shudder. I tried using forward cyclic to regain airspeed, but to no avail. I crashed into a farm field that was plowed and completely devoid of all vegetation." According to an inspector from the Federal Aviation Administration (FAA), the landing skids had collapsed. The tail boom was separated from the aft fuselage, and an indentation was found on the tail boom, consistent with main rotor blade strike. The pilot's seat was crushed down. The helicopter was re-examined under the supervision of an FAA airworthiness inspector, with representatives from Schweizer Aircraft Co, and Textron Lycoming. According to the report from a representative of Schweizer Aircraft Co.: "...All three rotor blades were still attached to the rotor hub. One blade (yellow) was bent and deformed significantly, the other two were straight and intact, exhibiting only minor compression buckles at the root end trailing edge...General condition of the rotor system indicates minimal rotor RPM at impact...All [flight] controls showed continuity although the cabin damage restricted the travel of the cyclic...Measurement of the MR [main rotor] Pitch Links indicate they are slightly shorter than nominal length and that the collective rod was long. These measurements are very close to the average aircraft after production flight test and aircraft certification...The engine rotated with signs of compression on all cylinders. The valve train upper end was intact and appeared to operate satisfactorily. The magnetos were removed and spun up with spark seen at all lead ends. The oil screen and filter were checked and found clear of debris. The FAA investigator on site reported a strong fuel smell at the scene and there was residual fuel in the carburetor when it was disconnected...."