On October 15, 2024, at 1514 central daylight time, a Rans S12S, N912RS, was involved in an accident near Church Point, Louisiana. The airline transport pilot sustained fatal injuries. The airplane was destroyed. The airplane was operated under Title 14 Code of Federal Regulations as a Part 91 maintenance test flight. The airplane had not flown for about three years before it was purchased by the current owner whose intent was to learn how to fly using the accident airplane. The airplane owner, the pilot, and two other individuals performed maintenance on the airplane during the previous two months in preparation for the test flight that was flown by the pilot. During the test flight, the pilot performed maneuvers that included aerodynamic stalls, steep turns, and glide ratios. The pilot reported via radio that there were no issues with the airplane, and it was outstanding in its flying. The pilot then reported that he was returning to the departure airstrip. The airplane entered a downwind landing followed by a base leg for landing. During the turn from the base leg to the final leg of the approach, the airplane snapped over and entered an aerodynamic spin. The airplane descended while spinning and the engine sound increased and then decreased, which was consistent with an application followed by a reduction of engine power. The airplane impacted a field and was destroyed by impact forces. Postaccident examination of the airplane revealed no mechanical malfunction/failure that would have precluded normal airplane operation. The airplane was not equipped nor was it required to be equipped with a stall warning system due its experimental categorization.