What happened
On July 6, 2002, at approximately 18:45, a Morane Saulnier MS 317, registration F-BBZR, was conducting a private flight from Rouen to Morlaix. The pilot had previously made a stop in Flers and was cruising at roughly 1,000 feet above the Guingamp-Morlaix expressway when a gradual decrease in oil pressure was observed. While the oil temperature remained within normal parameters, the pressure continued to drop until it reached the minimum threshold.
As the engine power progressively declined, the pilot noted smoke and oil droplets emanating from the engine and exhaust area. Because the pilot was not in radio contact with Morlaix at the time, they began searching for a suitable landing site in the countryside. The pilot identified a field that appeared sufficiently long for an emergency landing; however, during the final approach, an electrical line was spotted crossing the intended field. Using the remaining engine power, the pilot applied full throttle to maneuver and successfully landed the aircraft in an alternative field characterized by an upward slope. There were no injuries and no damage to the aircraft.
The investigation
The investigation focused on the mechanical failure of the Continental W-617-6A radial engine. Upon inspection of the engine oil, investigators discovered the presence of metal shavings (swarf) within the oil supply.