On July 18, 2019, about 2100 mountain daylight time, an experimental amateur-built Judd Challenger II airplane, N77YD, sustained substantial damage when it was involved in an accident near Draper, Utah. The pilot was not injured. The airplane was operated by the pilot under the provisions of Title 14 Code of Federal Regulations Part 91 as a personal flight. The pilot reported that during cruise flight, about 800 to 1,000 ft above ground level, he advanced the throttle and the engine immediately lost power. The pilot’s attempt to restart the engine was unsuccessful and he initiated a forced landing to a nearby tree-lined residential road. During the landing sequence, the airplane struck trees and came to rest upright against a fire hydrant. Examination of the airplane by a Federal Aviation Administration inspector revealed that the right side of the fuselage was structurally damaged. The inspector reported that following recovery of the airplane to a secure location, he and the owner examined the Rotax 503 engine. The fuel and carburetor float bowl were free of debris and the spark plugs appeared to be in normal condition. The inspector stated that there was good compression, with no binding noted when the propeller was rotated by hand. The inspector further stated that they conducted two separate engine runs on the airframe at various power settings with no anomalies noted.