On April 9, 2008, about 1325 central daylight time, a single-engine Hawker Beechcraft G36 airplane, N984W, was substantially damaged during a forced landing following a loss of engine power near El Dorado, Kansas. The airline transport pilot, the sole occupant of the airplane, was not injured. The airplane was registered to and operated by Hawker Beechcraft Corporation, of Wichita, Kansas. Visual meteorological condition prevailed and no flight plan was filed for the 14 Code of Federal Regulations part 91 production test flight. The local flight departed the Beech Factory Airport (BEC), Wichita, Kansas at approximately 1310 for its maiden flight. The pilot reported that while climbing through 5,000 feet, the airplane experienced a total loss of engine power. Following an unsuccessful engine restart attempt, the pilot elected to perform a forced landing on a nearby road. During the landing roll out the airplane's right wing sustained structural damage when it contacted a fence post. The airplane came to rest in an upright position and the pilot was able to exit the airplane unassisted. On April 11, 2008, representatives from Hawker Beechcraft Corporation and Teledyne Continental Motors examined the engine with oversight provided by the Federal Aviation Administration. The examination revealed that brass plug part number 629518-1 had fallen out of the fuel manifold valve which resulted in the loss of engine power. The threads on the brass plug and in the fuel manifold valve were found unremarkable, suggesting that the brass plug was not sufficiently torqued at the time it was last installed. A determination as to the brass plug's last installation could not be established.