On July 16, 2001, approximately 0315 central daylight time, a Piper PA-28-180, single-engine airplane, N8454W, sustained substantial damage during a hard landing at the Bridgeport Municipal Airport, Bridgeport, Texas. The airplane was owned by a private individual. It had been stolen and was being operated by a non-certificated pilot under 14 Code of Federal Regulations Part 91. The pilot and his passenger received serious injuries. Night visual meteorological conditions prevailed for the flight, and a flight plan was not filed. The flight originated from Weatherford, Texas, at an unknown time, and the flight was possibly en route to Durant, Oklahoma. The owner of the airplane reported to the local authorities and the NTSB investigator-in-charge (IIC) that the airplane was stolen. At 1900, on the evening prior to the accident, the owner had last seen his airplane tied down in his open "T" hangar at the Parker County Airport in Weatherford, approximately 25 nautical miles south of Bridgeport. Local authorities, the FAA inspector, and the engine and airframe manufacturer representatives, who responded to the site, found the airplane resting on the approach end of runway 17. The initial impact scraps and gouges on the runway contained white paint consistent with the color of the aircraft. Physical evidence found at the accident site indicated the airplane impacted the runway at about a 20-30 degree nose down attitude then slid about 90 feet before coming to rest approximately 5 feet to the right of the runway centerline. The integrity of both fuel tanks was compromised and fuel stains from an estimated 10 gallons of fuel were found spread over the runway. One propeller blade had rotational scoring and leading edge gouging and displayed rotational twisting approximately one-foot inboard from the blade tip. Control continuity was established via the cables. The flaps were in the retracted position, and the fuel selector was on the right fuel tank. The cockpit throttle control was at idle and the mixture control was full forward. According to the airframe manufacturer's representative, there were no discrepancies with the airframe "that would preclude normal operation prior to the impact." Local authorities reported dark night conditions with 1/8 moon. The runway lights and rotating beacon were "ON." On July 18, 2001, the engine was examined at Air Salvage of Dallas by the engine manufacturer's representative, under the supervision of the NTSB IIC. The carburetor was removed from the engine and hand operation of the accelerator pump expelled fuel from the carburetor bowl. The carburetor fuel screen was clean and clear of debris. The engine crankshaft was rotated and continuity was noted from the propeller flange through the accessory case. Thumb suction and compression were verified on all cylinders and all valves operated. The magnetos were removed and sparked at all terminals when rotated. According to the engine manufacturer's representative, there were no discrepancies with the engine "that would preclude normal operation prior to the impact." According to the FAA inspector, the non-certificated pilot had never held a pilot certificate. Local authorities reported that the non-certificated pilot had 6 hours of previous flight time.