Incident
The pilot reported a normal preflight and takeoff. After leveling off at about 1,100 feet above ground level to remain below Class B airspace, he activated the standby vacuum pump and noted it operating properly. Approximately 1–2 seconds later, the alternator annunciator light illuminated. The two passengers smelled something burning about 2 seconds after the annunciator light came on. The pilot stated that about 2 seconds after that, the engine lost power abruptly, without any roughness or surging. He elected to perform a forced landing to a river. The airplane sustained substantial damage.
Examination Findings
Examination of the engine compartment revealed an area of heat and fire damage near the top of the engine. Bare wires on the P-leads were found in the area of the heat damage. When the magnetos were checked, the P-leads were observed to be grounded, and no electrical current was reaching the magnetos. Further examination disclosed that a B-nut fuel line connector on the fuel line running from the engine-driven fuel pump through the engine baffling was loose. The loose fuel connector was located adjacent to the burned area where the P-leads had burned through.
Recent Maintenance
The engine logbook indicated that prior to the accident flight, the oil and oil filter had been changed, and the standby vacuum pump had been replaced. The fuel line with the loose B-nut was situated directly above the standby vacuum pump.