On June 6, 2006, about 1750 central daylight time, a Schweizer 269C helicopter, N54LC, operated by the Lake County Sheriff's Department, sustained substantial damage when it impacted terrain following a practice autorotation and subsequent loss of engine power near Schererville, Indiana. The helicopter was operating as a public-use instructional flight. The flight was conducted under 14 Code of Federal Regulations Part 91 and was operating in visual meteorological conditions. No flight plan was on file. The pilot reported no injuries and the co-pilot sustained minor injuries. The local flight originated from the Griffith-Merrillville Airport, near Griffith, Indiana, about 1700. The pilot's accident report, in part, stated: I was acting as a more experienced safety pilot for a certified helicopter pilot that was conducting a refresher flight after being recently reassigned to the Sheriff's department Aviation Division. After approximately a half hour of flight operations in the form of hover work, pedal turns, normal take off in the traffic pattern and return to normal approach to landing, I requested and received positive control of the aircraft from the less experienced pilot and was flying and controlling the aircraft from the co-pilot seat with the dual controls that were installed. I have flown this particular aircraft from the co-pilot side on previous flights so this presented no unknown challenges. The aircraft had recently been re-configured in that, floats (permanent, not pop out) had been installed after they had been removed approximately 5 years earlier. I have previously flown this aircraft in this float equipped configuration so this presented no unknown challenges to during this flight. Since the [floats] had been recently installed and since it had been some time since they were attached to the aircraft, I felt that it was necessary to conduct emergency procedure training for myself in the form of a practice autorotation to refresh my experience in this aircraft configuration. ... The aircraft was configured for the practice autorotation in that the aircraft was at 1200 MSL [mean sea level] or approximately 500 feet AGL [above ground level] and the airspeed was indicating 75 mph. The heading was approximately SW or 230 degrees. I have practiced hundreds of autorotations from this initial configuration and in the same geographical location, to the point that the point of intended touchdown was the same as nearly all other practice autorotations. Upon determining the point of entry or the practice autorotation, I flew to that point and started the maneuver. Immediately upon reducing the throttle and lowering the collective, the engine of the helicopter stopped. This was confirmed by the indication of the "split" needles and engine RPM indicating zero RPM. This was further confirmed by the manifold pressure gauge which was rising to atmospheric pressure. This practice autorotation had turned into a real total loss of engine power autorotation to touchdown. I monitored the rotor RPM and established best autorotation airspeed at 60 mph to maintain the autorotation decent. Upon nearing the ground at a height of approximately 30-50 feet, I flared the helicopter to slow the forward airspeed. I then leveled the aircraft and pulled up on the collective, using the stored energy in the rotor system to help control the vertical airspeed from a height of approximately 5-6 feet. The aircraft came to rest in an upright position and both pilot occupants remained inside and were not ejected. The main rotor blade flex downward and came in contact with the tail boom section causing the tail rotor to separate. Federal Aviation Administration inspectors examined the wreckage. No pre-impact anomalies were detected. The engine, a Lycoming HIO-360-D1A, serial number L-25796-51A, was operational during a subsequent test run. At 1745, the recorded Lansing Municipal Airport, near Lansing, Illinois, weather was: Wind 220 degrees at 13 knots gusting to 19 knots; visibility 10 statute miles; sky condition scattered 7,500 feet broken 10,000 feet; temperature 27 degrees C; dew point 11 degrees C; altimeter 29.84 inches of mercury.