HISTORY OF FLIGHT: On May 9, 1993, at 1835 central daylight time, a Cessna 150M, N63574, was destroyed on impact with the ground near at Liberty, Texas. The airline transport rated pilot (ATP) and his passenger sustained fatal injuries. Weather for the local area flight was visual meteorological conditions. Crystal Finger Corporation was the registered owner. Information provided by the owner to the investigator in charge (IIC) indicated that the ATP, who was also a certified flight instructor (CFII), rented the airplane for the purpose of showing his passenger the local area. A witness observed the airplane circling the area and heard the engine "splutter and then go silent." He further reported that the airplane "suddenly dropped its nose and dove to the ground." The airplane impacted approximately 250 yards from the airport and in a large pasture, approximately 100 acres. PERSONNEL INFORMATION: Information provided by friends of the passenger indicated that he was a former military pilot; however, the passenger held no U.S. civilian pilot's certificates or had been issued a medical certificate. Friends of the pilot reported that he had flown in the Iranian Air Force as a fighter pilot. The emergency medical personnel and local law enforcement officials positively placed the pilot in command in the right seat. AIRCRAFT INFORMATION: A review of the records and a physical examination of the aircraft revealed no pre existing conditions that would have contributed to this accident. WRECKAGE AND IMPACT INFORMATION: An examination of the physical evidence at the scene revealed that the airplane was imbedded in the ground nose first and the fuselage was in an erect position 90 degrees from the terrain angle. There was evidence of rotational rubbing on the ground in a clockwise direction. Both wings exhibited folding of the leading edges, the right wing leading edge was folded in an upward motion, and the left wing leading edge was folded in a downward motion. The right wing tip navigation light was found in a hole at the beginning of the rub marks and pieces of glass were scattered along the rub mark. Signatures in the ground were measured; they corresponded with the manufacturer's published dimensions for the aircraft's wing span. It was documented that the engine throttle was in the closed position (full aft) and bent so that it could not be pushed forward. MEDICAL AND PATHOLOGICAL INFORMATION: An autopsy on the pilot was performed by the Travis County, Texas, Medical Examiner. Toxicology testing was performed by the Civil Aeronautical Medical Institute, Oklahoma City, Oklahoma. Their testing established that the pilot in command's urine contained morphine marihuana; however, none was found in the in the blood. The Regional Flight Surgeon's enclosed report does not categorize the pilot as impaired from these drugs. TESTS AND RESEARCH: The engine was examined after removal from the air frame, no anomalies were found.