On November 25, 2008, about 1530 Pacific standard time, a Nickel RV-6 amateur-built experimental airplane, N6TR, sustained substantial damage during a forced landing following a loss of engine power after takeoff from Sierra Sky Park Airport, Fresno, California. The private pilot, the sole occupant, who was the owner and builder of the airplane, was seriously injured. Visual meteorological conditions prevailed, and no flight plan was filed for the local personal flight conducted under 14 Code of Federal Regulations Part 91. The flight was originating when the accident occurred. The pilot reported that prior to takeoff; he performed a high-speed taxi test on the runway with no anomalies noted. The pilot taxied back to the run-up area, performed his preflight checklist uneventfully, and proceeded to takeoff. During the takeoff initial climb, the engine misfired and developed "marginal power." As he executed a left turn towards the airport, the engine lost power. The pilot further stated "to take advantage of relatively good landing opportunities below," he continued the left turn and initiated a forced landing to an open area on a golf course. During the landing roll, the airplane struck a berm and became airborne again. Subsequently, the airplane landed hard and came to rest upright. Examination of the airplane by a Federal Aviation Administration inspector revealed that the airplane came to rest within a golf course about 1 mile northwest of the runway. The engine was partially separated from the airframe, and the firewall was bent and buckled. Examination of the converted Ford engine by the pilot revealed the fuel system was intact and undamaged. The pilot also reported finding "no obvious" anomalies with the ignition system. The reason for the loss of engine power was not determined.