On June 26, 2002, approximately 1930 central daylight time, a Beech BE-V35B single-engine airplane, N1SU, was substantially damaged during a forced landing following a loss of engine power while on final approach to the Baton Rouge Metropolitan Airport, Ryan Field (BTR), Baton Rouge, Louisiana. The private pilot and his passenger, who were co-owners of the airplane, sustained minor and no injuries, respectively. Visual meteorological conditions prevailed, and a flight plan was not filed for the 14 Code of Federal Regulations Part 91 personal flight. The local flight departed BTR approximately 10 minutes prior to the accident. The pilot reported that the airplane had undergone recent maintenance, and he and the co-owner wanted to perform a test flight around the traffic pattern. After a preflight and a 10 minute engine run-up, the airplane departed BTR for a single traffic pattern flight. On downwind abeam the approach end of runway 22L, the pilot reduced the power to 15 inches of manifold pressure. During the turn to final approach to runway 22L, the pilot attempted to increase engine power; however, there was no response from the engine. The pilot applied full throttle with the auxillary fuel pump turned ON; however, there was still no change in engine power. After performing a "safety check," the pilot realized he would not make the runway and initiated a forced landing to a field. During the forced landing, the airplane impacted trees and a roadway ditch, crossed a road, and came to rest upright short of the airport. The engine was removed from the airframe and shipped to the manufacturer's facility for further examination by the National Transportation Safety Board (NTSB). According to an FAA inspector, who responded to the accident site, the nose gear was separated, the firewall was bent, and both wings sustained structural damage. A review of the airframe and engine maintenance records revealed that the engine underwent it's most recent 100-hour inspection on August 13, 2001, at a total time of 5,964.2 hours, and 1,993.2 hours since major overhaul. On June 18, 2002, at a total time of 6,126.3 hours, an air/oil separator was installed in accordance with (IAW) supplemental type certificate (STC) SA02033AT. This installation was the most recent maintenance performed on the airplane. On September 16, 2002, at the facilities of Teledyne Continental Motors (TCM) in Mobile, Alabama, under the supervision of the NTSB, the engine was examined and test run. The engine was test run for 40 minutes at various power settings. During the engine test run, a magneto drop test was performed, and a high drop on one magneto was noted. At the completion of the test run, due to the high magneto drop on the test cell, the the engine timing was check. The timing check revealed that the right magneto was at 20 degrees before top center (BTC), and left magneto was at 22 degrees BTC. According to TCM technicians, the engine developed power on the test cell. "No discrepancy was found on this engine inspection that would have caused a power loss."