Accident Details
During the climb to cruise flight, the aircraft experienced a decrease in fuel flow. Cylinder head temperature and oil temperature increased, and an odor of overheating was detected inside the cockpit. When the engine began to sputter, the fuel pump was engaged. Shortly thereafter, the engine quit entirely. The pilot performed a forced landing in a pasture. During the landing roll, the landing gear collapsed.
Subsequent examination revealed evidence of a fire. The fire resulted from a leak at the main fuel line B-nut located in the engine compartment.
Investigation Findings
Investigation determined that the B-nut on the main fuel line had been loosened and not retightened during replacement of the standby vacuum pump. Additionally, the quality‑control inspector who examined the repair did not inspect the area surrounding the replaced standby vacuum pump. The loosened fitting allowed fuel to leak, leading to the engine malfunction and subsequent fire evidence.