On July 30, 2022, at 0911 mountain daylight time, a Cessna 172N, N6587E, sustained substantial damage when it was in involved in an accident near Broomfield, Colorado. The flight instructor and student pilot were uninjured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 instructional flight. The flight instructor stated that during the fifth touch-and-go landing, the student pilot’s landing approach was unstable. While the airplane was 20 ft above the runway, the airplane’s right main landing gear wheel was about 5 ft from the runway edge. The instructor told the student pilot to go around. The student pilot applied full engine power, but there was no “major increase of thrust from the engine.” The flight instructor then took the controls from the student. He said the airplane climbed very slowly out of ground effect and the flaps were at 40°. He retracted flaps, one notch at a time, and knew that upon incrementally retracting flaps, the airplane would sink to the ground. The instructor stated that he retracted flaps to 20° to reduce drag, but the airplane sank and was not accelerating with full engine power. The airplane then impacted the grass/ditch area on the left side of runway 29. The airplane sustained substantial damage to the left and right wings. The flight instructor stated he believed that the engine was not producing full power. Postaccident examination of the airframe revealed no mechanical anomalies that would have precluded normal operation. Postaccident engine testing revealed that the engine met the engine manufacturer’s test specifications.