On September 30, 2001, at 1750 eastern daylight time, a homebuilt Rotorway Exec 162F helicopter, N25GR, was substantially damaged during a forced landing in Whitehouse, Ohio. The certificated airline transport pilot was not injured. Visual meteorological conditions prevailed for the local personal flight that originated at the pilot/owner's home in Whitehouse. No flight plan was filed for the flight conducted under 14 CFR Part 91. According to the pilot, he conducted a 20-minute flight over his farm and was on final approach for his landing pad at the time of the occurrence. The engine started "missing and backfiring" and losing power at approximately 400 feet altitude. The pilot performed an autorotation to a soybean field, and as the helicopter touched down, it slid forward a few feet, then rolled over on its left side. The pilot also stated: "As far as controllability during the autorotation, everything worked the way it's supposed to. It wasn't until I got into the soybeans that the skid sunk in. Speed-wise it was all but stopped. The skid sunk in and the helicopter rolled onto its left side." The pilot reported 11,500 hours of flight experience, 65 hours of which were in helicopters. The pilot reported 20 hours of flight experience in the Rotorway Exec 162F. The pilot's most recent biennial flight review was completed June 29, 2001. The pilot's most recent first class medical certificate was issued on February 2, 2001. The helicopter was examined at the scene by a Federal Aviation Administration (FAA) inspector. According to the inspector's statement, the helicopter came to rest on its left side with the tailboom severed. The aft portion of the tailboom, with the tail rotor and tail rotor gearbox attached, was located about 25 feet from the main wreckage. The helicopter was equipped with a Rotorway International Fully Automatic Digital Engine Control (FADEC) system. According to the FAA inspector, the FADEC unit indicated an ignition failure code. The FADEC system was removed from the helicopter, and shipped to the manufacturer for examination under the supervision of another FAA inspector. According to the inspector's report, data downloaded from the FADEC revealed that for a 40-second period near the end of the accident flight, the engine temperature increased to 123 degrees centigrade, 22 degrees above the redline limit, before the engine stopped producing power. The FADEC system consisted of a primary and secondary Engine Control Unit (ECU). The FADEC was installed on an engine in a test cell, and the #1 and #2 ECUs operated the engine through its full operational range independently and together without an engine malfunction. The weather at Toledo, Ohio, 4 miles north of the accident site was clear skies with winds from 060 degrees at 3 knots.