On May 29, 2010, about 1854 central daylight time, a Pitts Aerobatics S-2B airplane, N260PK, was destroyed by fire during a post maintenance flight at the Blue Sky Airfield (2TX0), in Amarillo, Texas. The pilot, the sole occupant, sustained minor injuries. The airplane was registered to and operated by the pilot. Visual meteorological conditions prevailed and no flight plan was filed for the 14 Code of Federal Regulations Part 91 local flight. The flight originated moments before the accident. Reportedly, the purpose for the flight was a test flight following an engine tear down, inspection, and engine reinstallation. During the initial climb, while at an altitude of 700 feet above ground level (agl), the engine experienced a partial loss of power. The pilot initiated a 180 degree turn and performed a downwind landing on the runway he had just departed from. Following the landing, and while taxiing, the pilot observed flames emanating from the engine cowling area. The pilot shut down the engine and exited the airplane. Moments later the airplane was engulfed in flames. An examination of the airplane's engine conducted by a Federal Aviation Administration (FAA) inspector who responded to the accident site, revealed that the engine driven fuel pump housing had fractured where the fuel line fitting had been inserted. The fitting, with its pipe thread, was the correct fitting; however, its pre-accident torque value is unknown. Due to thermal damage to the pump housing, the reason for the failure could not be determined.