On November 21, 2002, about 1455 Pacific standard time, an experimental helicopter, an Asmus Rotorway Exec 162F, N162LC, rolled over on touchdown during an autorotation after a loss of engine power near Monterey, California. The pilot was operating the helicopter under the provisions of 14 CFR Part 91. The pilot, who held a private pilot certificate for helicopters, was not injured. The helicopter sustained substantial damage. The local flight departed Marina Municipal Airport (OAR) about 1345 Pacific standard time for the local area flight. Day visual meteorological conditions prevailed and no flight plan had been filed. The pilot, who was the builder of the helicopter, stated the purpose of the flight was a sightseeing trip to build his flight time. The helicopter developed engine problems during cruise flight along the coastline. The pilot said the engine "failed as if someone turned off the ignition switches." The pilot initiated an autorotation from 600 feet above ground level (agl) to a beach. The helicopter rolled over during the landing. The pilot stated the rollover was "probably due to tailwind and pilot technique." The pilot reported he held an airline transport pilot certificate for airplane multiengine land, a commercial pilot certificate for airplane single-engine land, a flight engineer certificate for jets, and an airframe and powerplant mechanic certificate. His total flight time was 18,000 hours, with 150 hours total time in helicopters. A post accident examination of the full authority digital engine control (FADEC) was performed at Rotorway International under the supervision of a Federal Aviation Administration inspector. Normal operating rpm for the engine is 4,180 to 4,250 with idle rpm at 1,700 to 1,800. After approximately 58 minutes of flight, the engine rpm went below normal operating rpm. In the last 25 seconds of flight, the engine rpm varied below operating rpm with the throttle at minimum openings. For 1 second, the engine was recorded at 1,100 rpm. There was no time thoroughout the flight that the FADEC system recorded a fault from engine operation.