On November 16, 1997, at 1130 hours mountain standard time, an Adams Sonerai II experimental airplane, N27KF, nosed over during a forced landing in rough desert terrain near Kingman, Arizona. The forced landing was precipitated by a loss of engine power during the takeoff initial climb from the Triangle Airpark Airport. The aircraft was destroyed and the pilot was fatally injured during the impact sequence. The aircraft was owned and operated by the builder/pilot. Visual meteorological conditions prevailed and no flight plan was filed. The flight was originating at the time as the return portion of a personal cross-country flight and was destined for North Las Vegas Airport when the accident occurred. Information concerning the accident circumstances was obtained from Federal Aviation Administration inspectors, witnesses to the accident, and responding Mojave County Sheriff's Department officers. The aircraft was part of a flight of three that flew from North Las Vegas to the Triangle Airpark earlier in the day. After visiting with friends in the nearby trailer park, the three aircraft were departing for the return to Las Vegas. The accident aircraft was the middle one of the three in the takeoff sequence. The pilot of the last aircraft reported that accident aircraft was in the takeoff initial climb when it appeared to loose power and enter a descent toward the desert. The aircraft touched down and then nosed over in the dirt. Responding sheriff's deputies photographed and documented the accident site, which is located about 1-mile northwest of the airport. According to the deputies' report, the impact site is predominantly level, although several small washes traverse the area in a direction perpendicular to the aircraft's direction of travel. Two areas of disturbed dirt and gravel dimensionally close to the main landing gear width were noted on the northern lip of a wash. A large crater was found immediately north of the wash and contained wooden propeller fragments and other debris from the engine compartment. The aircraft was found about 30 feet north of the crater and inverted cockpit-down with the tail raised into the air. The main landing gear, firewall, and engine compartment were found collapsed rearward onto the bottom side of the wing. Federal Aviation Administration (FAA) inspectors examined the airframe and engine with assistance from Teledyne Continental Motors following recovery of the wreckage. Control system continuity was established. The fuel selector valve was found in the off position. An estimated 12 gallons of automotive fuel was in the single fuselage fuel tank. According to the Teledyne Continental representative, no preimpact mechanical malfunctions or failures were identified during a complete disassembly of the engine, magnetos, and carburetor. A complete report of the examinations is appended to this report. A review of the airframe and engine maintenance records disclosed that the airplane was first issued an experimental airworthiness certificate following construction completion on March 27, 1997, and had accumulated approximately 75 hours. The Continental A75-8F engine, serial number 42741-6-8, had accrued a total time in service of 2,405 hours, with 923 hours since major overhaul. An autopsy was conducted on the pilot by the Mojave County Medical Examiner, with samples retained for toxicological tests. The results of the toxicological examinations were negative for alcohol and all screened drug substances.