On October 5, 2017, at 1053 Pacific daylight time, an experimental amateur-built Glasair Super II RG, N248ST, was substantially damaged when it was involved in an accident near Santa Ynez, California. The pilot was not injured. The airplane was operated as a 14 Code of Federal Regulations Part 91 personal flight. The pilot reported his intent for the flight was to practice touch-and-go takeoffs and landings. The first takeoff and landing to a full stop was normal. The pilot taxied back, and the pilot initiated a full throttle takeoff. Shortly after lifting off at 70 knots, the pilot noticed that the engine stopped producing power and the airplane started to descend. The pilot reduced the throttle and initiated a forced landing to a grass field. The airplane traveled through the airport perimeter fence and continued to a road where it contacted a dirt berm. The wings were substantially damaged. The pilot reported that the engine continued to run, and the propeller continued to turn throughout the landing roll until the propeller hit the dirt berm and the engine stopped. An inspector from the Federal Aviation Administration responded to the accident site. He verified that fuel was present in the fuel tanks. The pilot told him that he had refueled the airplane with 15 gallons of fuel in each wing, about 2 weeks before the accident. The engine was not examined, and the reason for the partial loss of engine power was not determined.