On February 21, 2003, at about 1430 eastern standard time, a Beech A45, N34MR, registered to a private individual, overran the runway during a forced landing at the Merritt Island Airport, Merritt Island, Florida. Visual meteorological conditions prevailed at the time and no flight plan was filed for the 14 CFR Part 91 personal flight. The airplane was substantially damaged, and the commercial-rated pilot, and pilot-rated passenger were not injured. The flight originated from Merritt Island, about 1 hour before the accident. The pilot stated they were cruising at around 3,000 feet, when they decided to return to the airport for landing. He reduced engine power and pushed the nose over to start the descent. At around 2,000 feet, oil and grease covered the windscreen and the engine lost power due to the propeller separating. He performed emergency procedures, and at about 1 mile from runway 29, he had to sideslip the aircraft in order to see out in front and to lose airspeed. The aircraft touched down at around the midpoint of the runway and was going too fast to stop. The airplane rolled off the end of the runway into a ditch causing the nose landing gear to collapse. Examination of the aircraft revealed both propeller blades were separated and not located. The propeller hub which remained attached to the engine was retained for further examination. Metallurgical examination of the propeller hub by the NTSB Materials Laboratory, Washington, D.C., revealed no evidence of cracking in the sockets or anywhere else on the hub. Both sockets exhibited damage to the threads to the same depth (about 2 or 3 threads from the internal end of the threads). Damage to varying degrees to both sockets was noted circumferentially. A few remnants of what appeared to be blade threads were found in the socket threads. No evidence of corrosion deterioration of the socket threads was noted. Review of the maintenance records revealed that the propeller was last overhauled on January 3, 1996, and was installed on March 10, 1998. The pilot later reported that following the return to service of the airplane after installation of the overhauled propeller, it would overspeed occasionally during takeoff or cruise. The rpm would never go more than 200 rpm greater than red line. When that occurred, he would put a load on the propeller to reduce the rpm. He also reported intentionally accelerating the airplane on at least three occasions to the velocity never exceed speed (Vne) of the airframe in an attempt to induce propeller overspeed, the results were unsuccessful. The propeller governor was then removed and checked, no discrepancies were reported. On August 5, 1999, the maintenance records reflect an entry which indicates the propeller was disassembled and the seals were replaced and the blades were backed off 1 notch. The work was performed by the facility that had overhauled the propeller in 1996. The propeller was reinstalled and dynamically balance checked on June 8, 2002; the vibration was recorded to be .135 inches per second (IPS) and no weight was required. The pilot also reported that following the propeller disassembly in August 1999, the overspeed condition did not occur again. The airplane minus the retained propeller hub was released to Dr. Kerwin, on March 8, 2004. The retained propeller hub was also released to Dr. Kerwin, on March 8, 2004.