ERA11LA242

According to the pilot, during cruise flight the engine began to run rough and lose power. He heard a loud metallic sound; the engine vibrated violently and then lost power. He performed a forced landing to a farm field, and the airplane nosed over in the soft terrain, resulting in substantial damage to the wings. A postaccident inspection revealed that the crankshaft would not rotate. An internal inspection of the cylinders and spark plugs did not reveal a reason for the power loss. The oil system was examined and there were large amounts of metal particles in the oil. Due to a lack of suitable equipment and facilities, further disassembly of the engine was not attempted.

On April 11, 2011, about 1216 central daylight time, a WSK-Meilec AN-2, N122AN, was substantially damaged following a loss of engine power and forced landing near Loxley, Alabama. The certificated commercial pilot and two passengers were not injured. The airplane was registered to and operated by Vertol Systems Company, Inc. under the provisions of 14 Code of Federal Regulations Part 91, as a personal flight. Day, visual meteorological conditions prevailed and no flight plan was filed. The flight originated from Fort Walton Beach, Florida (DTL), about 1118, and was destined for De Ridder, Louisiana (DRI). The pilot reported that, while in cruise flight at 1,000 feet above ground level, the engine began to run rough and lose power. He then heard a loud, "metal-on-metal" sound, the engine vibrated violently, and it subsequently quit completely. The airplane was force landed in a farm field and nosed over in the soft terrain. An inspector with the Federal Aviation Administration responded to the accident site and examined the airplane and engine. Structural damage to the wings was evident. The radial engine was a WSK-PZL model ASZ-621R. The spark plugs were removed and all cylinders were inspected with a borescope. No abnormal characteristics were noted. The engine could not be rotated manually. Examination of the engine oil screens revealed an “extreme” amount of metal particles in the oil supply. Due to a lack of suitable equipment and facilities, a more detailed examination of the engine was not performed.