On May 31, 2003, approximately 1030 central daylight time, an Aerotek Pitts S-2A single-engine aerobatic bi-plane, N97DW, sustained substantial damage following a partial in-flight breakup while maneuvering near Grand Prairie Municipal Airport (GPM), Grand Prairie, Texas. The commercial pilot and his passenger were not injured. The airplane was registered to and operated by the pilot. Visual meteorological conditions prevailed, and a flight plan was not filed for the 14 Code of Federal Regulations Part 91 personal flight. The local flight departed GPM at 1020. In an interview with the NTSB investigator-in-charge, the pilot stated that approximately 5 minutes into the flight, he was performing a power-on stall. During the stall, the airplane broke to the left, and then the airplane entered an inverted spin. During the recovery from the spin, an outboard section of the bottom left wing separated. Subsequently, the pilot returned to GPM and landed uneventfully. In an interview with an FAA inspector, the pilot stated that during the spin, the aircraft performed approximately two rotations. To recover the airplane, the pilot reduced power, and the airplane entered a nose low attitude. The pilot "pulled hard" to recover from the nose low attitude, and the airplane again broke to the left. During the recovery from the ensuing dive, the airplane was shuddering and a section of the lower left wing separated. The pilot stated that after the flight, the 'G' meter read +7.2/-2, and the flight lasted a total of 10 minutes. The FAA inspector reported the airplane has a +6/-3 'G' limit load factor, and a +9/-4.5 'G' ultimate load factor. In addition, the pilot reported approximately 30 days prior to the accident flight, during a low altitude pass over some of his property, the airplane impacted the tops of some trees. The pilot repaired the airplane fabric damage with duct tape and did not report what additional inspections and/or repairs had been completed. He also had not received any formal aerobatic instruction and was learning aerobatics on his own. Examination of the airplane by the pilot revealed that a 4-foot portion of the bottom left wing and the left aileron had separated from the aircraft. According to an FAA Airworthiness Inspector who examined the airplane, the forward wooden wing spar was splintered and fractured, and the aileron was separated. The separated section and aileron were not recovered. Numerous attempts to obtain a completed NTSB Pilot/Operator Aircraft Accident Report (NTSB Form 6120.1/2) from the pilot were unsuccessful.