On July 14, 2019, about 1924 central daylight time, a Cessna T188C airplane, N2863J, was substantially damaged when it impacted terrain near Knox, Indiana. The pilot sustained serious injuries. The airplane was registered to and operated by AAA Spraying Solutions, LLC dba Bluebird Ag, as a Title 14 Code of Federal Regulations Part 91 aerial application training flight. Visual meteorological conditions prevailed, and the flight was not operated on a flight plan. The local flight originated from the operator's airstrip about 1900. The pilot reported that he did not have any memory of the events leading up to, or of any portion of, the accident flight. He had not completed any agricultural application work within the previous 2 years and was reestablishing his currency at the time of the accident. The operator stated that the pilot was practicing by spraying water along the operator's airstrip. The pilot completed several takeoffs and landings, and then sprayed 40 gallons of water over the runway. After landing, the pilot commented that the airplane had gotten down to 60 mph in the turns. The pilot was informed that the minimum airspeed in turns was 80 mph. An additional 80 gallons of water were loaded onto the airplane for another practice flight. The pilot conducted a couple more passes over the runway and appeared to be returning for another pass, when the airplane pitched up to clear a group of trees before entering a left turn. The airplane appeared to get "very slow in the turn." The witness "heard the engine go to full power" as the left turn continued. The wings leveled momentarily before the airplane entered a second left turn that "just kept getting steeper." The airplane impacted the ground with a 60° to 70° bank angle. A second witness, who was an agricultural application pilot and familiar with the accident airplane, reported that the initial passes with 40 gallons of water were completed without incident; although, the pilot "seemed to be slightly aggressive in the turns." After the pilot landed, the airplane was loaded with 80 gallons of water. While the airplane was being loaded, the pilot "mentioned something about turning at 60 mph indicated" airspeed. The witness stressed to the pilot his own comfort level of never flying below 80 mph indicated airspeed. The pilot took off and completed three more practice passes. His final pass was from west to east, and he executed a "very steep field exit." The pilot held the airplane in a nose up attitude longer than required to clear the obstacles. The pilot then executed a left 270° turn. The engine sounded as if it was making full power after the pilot rolled wings level. The pilot appeared to begin lowering the nose, but then seemed to begin pulling up before the airplane had regained sufficient energy. The airplane entered an "extremely slow climb;" wings level before abruptly rolling into a 60° plus left bank which continued until it descended behind trees immediately before impact. The witness noted that he was close enough to see the control surfaces and they appeared to be responding to pilot inputs during that final turn. A postaccident examination conducted by a Federal Aviation Administration inspector revealed damage to the forward fuselage, both wings and the empennage. The inspector did not report any anomalies consistent with a preimpact failure or malfunction. The airplane owner's manual noted aerodynamic stall airspeeds of 73 mph at a 0° angle of bank (wings level) and 103 mph at a 60° angle of bank when operating at 4,400 lbs gross weight with wing flaps retracted. The manual added that the airplane stall characteristics are conventional, and the stall warning should sound 5 to 10 mph above the stall speed in all configurations.