On June 7, 2000, at 1455 central daylight time, a Bellanca 17-31ATC airplane, N39827, was substantially damaged during a forced landing following a loss of engine power near Del Rio, Texas. The commercial pilot and his passenger were not injured. The airplane was registered to and operated by the pilot. Visual meteorological conditions prevailed and a flight plan was not filed for the 14 Code of Federal Regulations Part 91 personal flight. The cross-country flight originated from the Stinson Municipal Airport near San Antonio, Texas, at 1330, and was destined for Eloy, Arizona. During a telephone interview conducted by the NTSB investigator-in-charge, the pilot stated that the airplane was in cruise flight at 12,500 feet and he was receiving flight following from the Del Rio Approach Control, when he noticed the manifold pressure drop from 37 inches to 19 inches of mercury. He also noticed the exhaust gas temperature gauge indicate a decrease in temperature. He informed approach control that he was having an engine problem and was given vectors to the Del Rio International Airport and instructions to descend to 4,000 feet. While descending through 5,000 feet, the #3 cylinder, along with the engine cowling, separated from the airplane. The pilot stated that he could not make it to the airport and elected to land the airplane on a highway. He noticed power lines near the highway during the approach and elected to land in a field, located east of the highway. The field was covered with mesquite trees. During the landing roll, the airplane impacted mesquite trees, and the landing gear collapsed. According to the FAA inspector, who responded to the accident site, the wooden wing spars were structurally damaged and the fuselage tubing was bent. The #3 cylinder, piston, and connecting rod were missing from the Textron Lycoming IO-540-KIE5 engine. Small metallic debris remained in the oil sump. Review of the engine maintenance records revealed that the original engine logbook was lost, and on October 1, 1983, it was estimated that the engine had accumulated 1,238 hours (at a tachometer time of 254.9). At that time, the engine underwent a 100-hour inspection and the propeller and turbocharger were replaced. On November 19, 1984, the #1 cylinder was removed and replaced at an engine total time of 1,312.10 hours. On November 6, 1989, after a propeller strike, a top overhaul and crankshaft run-out inspection were conducted on the engine at a total time of 1,615.6 hours. The last annual inspection recorded was on April 1, 1999, at a tachometer time of 835 hours, and the last 100-hour inspection on the engine was completed on March 28, 2000, at a tachometer time of 852.45 hours and an engine time of 1,830.55 hours.