At about 12:20 CST, a Miller/Bell TR-1 amateur-built experimental airplane was substantially damaged when it struck a building during a forced landing near Hiwasse. The two occupants, who built and owned the airplane, were not injured. The pilot told investigators that approximately 45 minutes into the flight the engine noise changed and the oil pressure gauge indicated zero. The pilot elected to make a precautionary landing on a road adjacent to a field and a poultry-house, but during the landing flare the wind pushed the aircraft into the side of the poultry-house. The pilot said that a post-accident inspection revealed that the connector for the oil cooler inlet line had backed off, allowing the oil to spill overboard.