On June 28, 1996, at 1030 central daylight time, a Ryan PT-22, N47621, registered to and operated by a private owner, sustained substantial damage when it impacted the ground following a loss of control while maneuvering near Krum, Texas. The private pilot sustained minor injuries, and his passenger was seriously injured. Visual meteorological conditions prevailed, and a flight plan was not filed for the Title 14 CFR Part 91 local personal flight. According to the pilot, he was practicing touch and go landings at Bird Dog Field Airport. During the turn from the crosswind to the downwind leg, the left wing "stalled and the aircraft turned almost inverted." The pilot "righted" the airplane prior to its impact in a field on the airport. The empennage and the engine separated from the fuselage, and the right wing sustained substantial damage. The pilot reported that he had accumulated a total of 30 flight hours in the Ryan PT-22; however, he had flown only 1 hour in this make and model of airplane during the 90 days preceding the accident.