19990620046039A

(.4)On June 20, 1999, about 2144 eastern daylight time, a Cessna 182Q, N937FB, was destroyed after impacting the water during a forced landing near Rising Sun, Maryland. The certificated commercial pilot was seriously injured, and three passengers received minor injuries. Night instrument meteorological conditions prevailed at the time of the accident. An instrument flight rules flight plan had been filed from linden municipal airport, linden, new jersey, to montgomery county airpark, gaithersburg, Maryland. The personal flight was conducted under 14 CFR part 91. The pilot stated to the Maryland state police that he departed linden municipal airport about 1845, and was headed for haysfield airport, clarksville, Maryland, when the engine began to run rough. Attempting to land at a nearby airport, utilizing only the airplane's instruments, he noted that the altimeter read zero. The pilot's next recollection was being upside down in the water. According to a narrative included with NTSB form 6120.1/2, supplied by the pilot's attorney, the pilot additionally stated that the airplane was in level flight at 4,000 feet, near Rising Sun, when the engine made a loud noise. Flames and sparks appeared, and the engine lost all power. The pilot contacted baltimore approach control and was advised that the only airport within the airplane's gliding distance was a grass strip to the south. The controller suggested a turn to the south and the pilot complied by turning the airplane to a heading of 180 degrees. The controller kept the pilot informed of the distance between the grass strip and the airplane. The pilot asked if the landing field was lighted and the controller responded yes. The last communication that the pilot recalled receiving from the controller was that the airplane had closed within 1/2 mile from the grass strip. The pilot continued to descend utilizing the airplanes flight instruments, but was unable to make visual contact with the ground. The pilot flew the airplane at the best glide speed until the airplane stopped moving. The airplane came to rest inverted in the susquehanna river. A federal aviation administration (FAA) inspector examined the wreckage on June 21, 1999. The airplane was observed inverted, partially on the western bank of the susquehanna river. The engine and its mount were displaced, and connected to the airplane only by wires and hoses. A large hole was observed on the top of the engine crankcase. The left side of the airplane had oil streaks from the engine cowl rearward to the rudder. The engine was removed and examined on June 23, 1999, under the supervision of a FAA inspector. According to the engine manufacturer representative, the engine had sustained an approximate 3-inch diameter hole in the top center of the case, adjacent to the number four cylinder. A second hole, about 1 1/2-inch in diameter, was observed near the number five cylinder. The heads of three connecting rod bolts and portions of a connecting rod bearing were recovered from the bottom of the oil sump pan. About one pint of oil was also present in the oil sump pan. The engine manufacturer representative additionally stated that, the main bearings were examined and none were observed to have shifted or rotated in place. The number one main bearing at the rear of the engine exhibited heating and accelerated wear. The number two and three main bearings exhibited the bearing surface to be "wiped and torn," blackened from the heat. The number four and five main bearings were not recovered. The number six main bearing also exhibited accelerated wear. The oil pump and filter were also disassembled and absent of debris. The number four and five cylinder connecting rod end caps and five connecting rod bolts were forwarded to the safety board materials lab for examination. All five of the bolts exhibited severe necking at the fracture and deformation in the shafts. The large amount of deformation and necking was consistent with a single deformation event that occurred at a high temperature. The connecting rod caps exhibited similar characteristics, a gross amount of deformation (in at least one case), but with a lack of fracture. This was consistent with deformation at a high temperature. Review of the airplane maintenance records reveal that the engine had been remanufactured by an overhaul facility on March 5, 1990. At the time of the accident, the engine had accumulated about 941 hours since remanufacture. The engines last annual inspection was on November 1, 1998, and the last recorded maintenance was on February 3, 1999. The weather at a nearby airport, reported, winds from 050 at 10 knots, visibility 4 miles, drizzle and mist, a broken layer of clouds at 400 feet, overcast clouds at 900 feet, temperature and dew point at 59 degrees fahrenheit. (-23)pilot reported rough engine to bwi approach at 2144 zulu. Aircraft lost off radar 8 minutes later. Impacted in conowingo reservoir, near western shore, flipped over and came to rest partially on the shore. Engine failed due to #4 and #5 connecting rods breaking. #4 holed engine case in 2 places. Tear down inpsection by tcm on 6/24/99. Specific cause of failures has not been determined. Engine had approximately 900 hours since major over haul. Maintenance did not appear to be a factor.