On July 9, 2026, about 1729 central daylight time, a Piper PA-30 airplane, N8154Y, was substantially damaged when it was involved in an accident near Tulsa, Oklahoma. The flight instructor and pilot under instruction were seriously injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 instructional flight. The flight instructor reported that while conducting training maneuverers in the practice area she heard a noise similar to “sputtering” from the right engine and noticed the RPM drop to about 1500 rpms. Shortly after the rpm drop, the noise stopped and the rpm returned to normal. However, due to unexpected right engine issue, she chose to return to the airport. While returning to the airport, the flight instructor reported that all the engine gauges were observed to be within their respective normal ranges. During the approach, the flight instructor took the flight controls from the pilot under instruction as she observed that the airplane was too high and drifting from the runway centerline. However, the flight instructor was unable to correct for the unstable approach and chose to perform a go-around. The flight instructor reported that the airplane suddenly rolled inverted to the right after she applied full engine power to perform the go-around. Video surveillance imagery showed the airplane start an initial climb during the go-around followed by a sudden inverted roll to the right and then impacting terrain in a vertical nose low orientation. The airplane sustained substantial damage to both wings and the fuselage. The airplane owner reported that both propeller governors had been recently removed, overhauled, and reinstalled. The airplane was retained for further examination.