On September 24, 2020, about 1918 central daylight time (CDT), a Cessna 172 airplane, N108VK, was substantially damaged and a Team Rockets F1 airplane, N540LK, was destroyed when they were involved in a mid-air collision near San Marcos, Texas. The flight instructor onboard the Cessna received minor injuries, the student pilot was seriously injured, and the F1 pilot received minor injuries. The Cessna was operated as a Title 14 Code of Federal Regulations (CFR) Part 91 instructional flight and the F1 was operated as a Title 14 CFR Part 91 personal flight. San Marcos Regional Airport (HYI) was equipped with an air traffic control tower, which was closed at the time of the accident. Aircraft in the traffic pattern were self-reporting on the common traffic advisory frequency (CTAF), and a recording of the radio communications during the time of the accident was obtained. The Cessna was equipped with a GoPro camera mounted in the aft interior of the cockpit that captured video of the pilots and communications during the accident flight. The F1 was a tandem, two-seat, low-wing monoplane which was not equipped with Automatic Dependent Surveillance – Broadcast (ADS-B) equipment. The Cessna was a 4-seat, high-wing monoplane that was equipped with ADS-B. The Cessna entered the left downwind about 1912 for a full-stop landing. The student pilot was flying the airplane when they entered the pattern and there were 6 other airplanes in the traffic pattern or communicating on the CTAF at that time, including the F1. The F1 pilot stated that, when he entered the left downwind for runway 8 from the northeast he noticed an airplane in front of him and abeam the landing threshold. He announced and performed a right 360° turn for spacing and reentered the downwind. The instructor in the Cessna heard the F1 enter the traffic pattern on downwind, but he did not see the F1 perform the 360° turn and he tried to locate it using ADS-B. As the F1 was abeam the runway 8 threshold, the Cessna queried if the airplane that performed the 360° turn had rejoined the traffic pattern. The F1 pilot responded that he had and was about to turn left base, but he saw a Cessna below him on downwind at his 2 o’clock position and 0.7 to 0.9 miles away. The instructor took control of the airplane, announced they were “over the stadium turning left base,” and started a left turn. The “stadium” referenced was the Texas State University football stadium, located 2.9 miles east of the approach end of runway 8. At 19:15:40, the F1 pilot announced he would extend his downwind and “rejoin on the final.” Another airplane announced that they were on a short final a few seconds later. About 15 seconds later, the instructor continued a left turn and reported via radio that he saw another airplane “over the stadium.” At 19:16:24, the F1 pilot reported “over [Interstate 35 (I35)] inbound for landing on final for runway 8.” I35 passes under the flight path to runway 8 about 2.25 miles east of the approach end of the runway. The F1 pilot stated that he visually cleared his flight path at that point and did not see another airplane on final until the collision occurred. Nine seconds later, the Cessna reported that they were on a 2-mile final to runway 8. At 19:17:20 the F1 pilot reported he was on a 1-mile final. The instructor quickly looked outside, including upward and backward, and at 19:17:25 the Cessna radioed they were at 0.8 mile on final. There were no additional radio calls from either airplane for the remainder of the flight. The instructor continued to look outside until 19:17:52, when he focused his attention toward the runway. The Cessna’s altitude indicated 750 ft mean sea level (155 ft above ground level) at that time. The F1 pilot recalled an airplane making position calls on final, which he assumed was the airplane he had seen at his 2 o’clock and that it was behind him. He stated, “I had a clear, clear view of the runway, there was no traffic at all between me and the runway,” and “Obviously, to what I understood they were behind me because obviously they were not between me and the runway.” The F1 pilot said that he felt and saw the other airplane impact from the right side, 5 o’clock position shortly after he made his 1-mile position call and before the impact with the ground. The instructor stated that he felt the F1 impact the Cessna from above and the left, and the F1’s propeller hit the windshield and top of their cowling. He said that he could not control the airplane as it descended, and it hit the ground and flipped over. The Cessna came to rest inverted on the airport perimeter road and the F1 stopped a short distance away against the airport perimeter fence. The F1 pilot exited his airplane and assisted the occupants of the Cessna. The F1 subsequently caught fire and was destroyed. The Cessna sustained substantial damage to the fuselage, empennage, and both wings. The Federal Aviation Administration (FAA) Airplane Flying Handbook (AFH), Chapter 7, provides the following information to pilots: When approaching an airport for landing, the traffic pattern is normally entered at a 45° angle to the downwind leg, headed toward a point abeam the midpoint of the runway to be used for landing. The pilot should ensure that the entry leg is of sufficient length to provide a clear view of the entire traffic pattern and to allow adequate time for planning the intended path in the pattern and the landing approach. Banking from time to time can uncover blind spots. A mid-air collision is most likely to occur between two aircraft going in the same direction.