CHI93LA371

During cruise flight the pilot noticed a loss of oil pressure and an increase in oil temperature on the left engine. He shut down the engine and diverted to the nearest airport. A VOR approach was made and due to the inability to maintain altitude, the pilot was unable to circle to land on the longer runway. During the landing roll, the airplane overran the end of the runway and contacted rough terrain. Post accident inspection revealed the number 4 main journal bearing had spun. Material from the bearing and the damaged crankcase had clogged the oil suction screen. Washers were found added to the oil pressure relief valve in an attempt to regulate the oil pressure. The engine was overhauled 350 flight hours prior to the accident.

On September 21, 1993, at 0640 central daylight time, a Piper, PA-60-601, N9825Q, registered to New Creations, Inc., overran the runway following a single engine VOR approach to Runway 18 at the Tri-County Airport, Lone Rock, Wisconsin. Visual meteorological conditions existed and an IFR flight plan was filed for the CFR 14 Part 135 cargo flight. The airplane was substantially damaged and the pilot was not injured. The flight originated from Chicago, Illinois, on September 21, 1993, at 0535 cdt.

The pilot reported that when south of Lone Rock while en route to St. Paul, Minnesota, the left engine rpm began to decrease. He reported he increased the propeller control at which time the oil pressure was 3 psi and the oil temperature gauge indicated 130 degrees C. He stated that engine rpm continued to decrease rapidly so he shut the engine down. He stated he informed Air Traffic Control of the situation and requested to go to the nearest suitable airport. The pilot reported he made a heading change toward Lone Rock during which his airspeed dropped to blue line (109 knots), he lost 600' in altitude and entered a 200 foot per minute descent which he could not arrest. He stated he decided to fly the VOR-A approach to runway 18 and circle to land on runway 27 which was 1415' longer.

The pilot reported that during the approach the right engine began to run rough and was 20 degrees over temperature. He stated that once he got sight of the airport during the approach, he decided he could not safely circle to land on runway 27. The pilot stated he was high for the landing so he extended the gear, lowered full flaps and entered a side slip. According to the pilot, the airplane crossed the threshold 5-10 knots too fast and touched down in the first 1/3 of runway. The airplane then traveled off the departure end of the runway into a grass area, crossed over a road and came to rest in a farm field.

Post accident inspection of the left engine revealed the oil suction screen was clogged by metal shavings. A tear down of the engine revealed the number 4 main journal bearing had spun. The bearing had disintegrated to the point where the case was worn. There were no indications of excessive heat inside the engine as a result of the spun bearing. The other main bearings showed signs of surface wear and fretting. The engine had been overhauled 350 hours prior to the accident. Initial post accident inspection of the engine by the Federal Aviation Administration Inspector revealed 2 washers had been placed in the oil pressure relief valve.