MIA04LA013

According to the pilot the engine lost oil pressure, and seized, at 2000 feet. The pilot notified ATC and was given a heading to the nearest airport. The pilot reported he could not make to the original airport, and was given a heading to a private airport, 4 to 5 miles closer. The pilot realized he was not going to make to the airport, and elected to land in a pasture. The pilot avoided power lines by flying under them, and while clearing a fence, the tail of the airplane struck the fence, impacted in a field, skidded until impacting another fence, and came to a stop. Examination of the engine revealed a hole in the crankcase near the number 4 cylinder, the number 4 connecting rod partially protruded the hole, and showed signs of heat distress. Internal examination of the engine showed high heat distress due to lack of lubrication. The oil pump was found intact and the oil passages were clear. The source of the loss of lubrication could not be determined.

On October 27, 2003, about 1615 eastern standard time, a Mooney M20J, N4103H, registered to and operated by a private individual, impacted with a fence during a forced landing about 7 miles northeast of Ocala, Florida. Visual meteorological conditions prevailed at the time and an instrument flight rules flight plan was filed for the Title 14 CFR Part 91 personal flight. The airplane was substantially damaged. The private-rated pilot reported no injuries, and one passenger reported minor injuries. The flight had departed Franklin, North Carolina, about 1330, and was enroute to Orlando, Florida.

According to the pilot, the airplane was functioning "normally" until about 20 miles southwest of Jacksonville, Florida. At that time he informed air traffic control (ATC) that the oil pressure gauge indicated that the engine was losing oil pressure. Oil pressure was slightly "below normal at that point." He requested the nearest airport, and Ocala, Florida, appeared to be the closest airport that was clear of any weather. As he headed towards' Ocala, oil pressure continued to drop. About 10 miles out, the oil pressure started to dip below the warning line. About 7 miles out, there was only a slight indication of oil pressure, and the "engine seized." The flight was at an altitude of 2,000 feet at that time. He informed ATC that he had lost an engine. ATC gave him a heading for a private strip 4 to 5 miles closer than Ocala. After realizing he would not make that airport, he selected a pasture for landing. He said the pasture required a right turn to line up for landing. After completing the turn, he identified a power line in the flight path. He elected to "go under" the power line rather than risking a stall going over it. After going under the power line, he lifted the nose to miss a fence, but struck the fence with the tail, and landed on the belly in the pasture, then skidded about 200 feet into a double fencerow, and came to a stop.

Examination of the engine, by an FAA Inspector and a representative of Lycoming engines revealed a hole in the crankcase near the number 4 cylinder assembles. A part of the number 4 connecting rod was found protruding through the hole, and the exposed connecting rod exhibited high heat distress. Disassembly of the engine revealed extruded bearing material from the number 4 rod in the oil sump and the suction screen. The oil filter contained fine metal particles. Fragments of the number 4 connecting rod cap, yoke, bolts were partially removed and the surfaces showed overload and high heat distress due to lack of lubrication. About 1 1/2 quarts of oil was found in the oil sump, there were signs of oil wetness down the lower right quadrant and near the engine stand. The number 1, 2, and 3 rod bearings showed signs of dirt and particles embedded. Secondary internal damage was found in the reciprocating power section, and at the accessory drive gears. A single steel ball, diameter 0.185 inch, was found in the oil sump, which was not part of the engine. The oil pump was intact and the oil passages were found clear. According to the FAA the connecting rod overload, and heat distress was caused by an undetermined lubrication problem.