Incident Description
During cruise flight at an altitude of 4,500 feet, the pilot observed a slight engine vibration and noted that fuel consumption had increased from 12.5 gallons per hour to 15.7 gallons per hour, with engine settings at 2,300 rpm and manifold pressure of 30.00 inches of mercury. Shortly after, the engine ceased operating, and the pilot executed a forced landing to a field. During the landing rollout, the airplane incurred damage.
Examination
An FAA airframe and powerplant mechanic with an inspection authorization rating responded to the accident scene. He reported finding the B-nut on the inlet side of the fuel flow divider loose by approximately one full turn. Additionally, he observed signatures consistent with a fuel leak that originated at the B-nut and ran down the right front of the engine case. A follow-on examination of the accident airplane revealed that at the connection of the B-nut on the fuel inlet line to the manifold, torque putty was present on the threaded connection on the manifold side, but no putty was observed on the B-nut. When conditions were recreated and the engine given a test run, fuel leaked from around the B-nut when the electric fuel boost pump was activated.
Maintenance History
According to the airplane's engine logbook, the engine had been rebuilt by Teledyne Continental Motors and shipped to Mod Works Inc., Punta Gorda, Florida, which installed it in the accident airplane on March 03, 2003. At the time of the accident, the engine had accumulated a total time of 80 hours since installation and had received two previous oil changes, both performed by Mod Works Inc.