0n September 9, 1995, at 1417 central daylight time, an Allen Mustang II, N11AA, collided with the ground during a climbout from runway 22 at Marion County-Brown Field in Jasper, Tennessee. The personal flight operated under the provisions of 14 CFR Part 91, with no flight plan filed. Visual weather conditions prevailed at the time of the accident. The aircraft sustained substantial damage; the pilot and passenger were fatally injured. The flight's exact departure time from Collegedale, Tennessee, was not determined. The fixed based operator at Collegedale Airport reported that the aircraft was refueled with eight gallons of aviation fuel before the flight departed for Jasper. There were no reports of the exact time the flight landed at Jasper. During the flight's attempted departure from Jasper, there were several witnesses at the airport. According to witnesses, the pilot executed a steep, left climbing turn after the lift off from runway 22. The witnesses also stated that the climb attitude appeared excessive, and remained excessive until the airplane stalled; the airplane subsequently rolled left and entered a spin. Examination of the airframe failed to disclose a mechanical problem or system malfunction. The examination of the accident site revealed that the aircraft sustained frontal ground impact damage. The engine assembly was displaced rearward into the cockpit area, and the wing assemblies sustained leading edge damage. Further examination revealed that the empennage was torn from the fuselage. An examination of the cockpit area disclosed that the pilot and passenger seat belt and shoulder harness assemblies had failed; both restraint systems were torn apart at the web stitching. An examination of the engine assembly failed to disclose a malfunction. The engine assembly sustained impact damage that also damaged the carburetor assembly. The examination revealed that the engine had been modified with an electronic ignition system that replaced one of the two normally installed magnetos. The one installed magneto was field checked, and produced an ignition spark on all cylinders. Despite the impact damage, the engine assembly was rotated, and no binding was noted. The autopsy on the pilot was conducted by Dr. Robert Harlen, at the Office of Forensic Science in Nashville, Tennessee, on September 9, 1995. Toxicological examinations were negative for drugs and alcohol.