SEA06LA141

While in a descent from cruise flight the engine sustained a total loss of engine power, resulting in a forced landing to a shoreline consisting of soft sand. A post accident examination of the engine revealed connecting rods 2, 3, 4, 5 and 6 were separated from the crankshaft. There was also evidence of connecting rod bearing heat stress and lack of lubrication, metal observed in the oil pan, and four penetrating holes in the bottom of the crankcase. Prior to preparing the engine for teardown only about one quart of oil was drained from the oil sump. The engine had accumulated a total of 1,956 hours since its most recent major overhaul; recommended time between overhauls is 2,000 hours. The pilot reported fuel and oil levels were normal for the flight and that no anomalies were noted, which would have precluded normal operation.

On July 7, 2006, approximately 1145 mountain daylight time, a Piper PA-32-300 airplane, N56824, sustained substantial damage following a loss of engine power and forced landing near Grantsville, Utah. The airplane was registered to and operated by a private individual. The certificated private pilot and his four passengers were not injured. Visual meteorological conditions prevailed for the personal cross-country flight, which was operated in accordance with 14 CFR Part 91, and a flight plan was not filed. The flight departed the Bend Municipal Airport, Bend, Oregon, about 0730 Pacific daylight time, and its destination was the Salt Lake City International Airport (SLC), Salt Lake City, Utah.

According to the Pilot/Operator Aircraft Accident/Incident Report (NTSB Form 6120.1), the pilot reported that prior to the cross-country flight he conducted a preflight check of the airplane, noting a full fuel load of 84 gallons, engine oil level normal, and engine run up normal. The pilot further reported that about three and one-half hours into the flight while over water and descending through 6,200 feet mean sea level, the engine "shuttered" and quit, necessitating a turn back to the nearest shoreline. The pilot stated that the landing was on very soft sand, and that during the rollout the left main landing gear separated from the airplane, the left wing tip dug into the sand, and the airplane ground looped 180 degrees to the left before coming to rest in an upright position. The pilot further stated that approximately 28 to 30 gallons of fuel remained on the airplane after the accident. A certificated airframe and powerplant mechanic, who assisted in the recovery of the aircraft, reported to the National Transportation Safety Board investigator-in-charge (IIC), that there was substantial damage to the airplane's left wing main spar.

On July 24, 2006, at the facilities of Beegles Aircraft Service, Greeley, Colorado, and under the supervision of a National Transportation Safety Board Senior Air Safety Investigator, the airplane's engine was disassembled and examined. The investigator reported that during the examination the following was observed: after the spark plugs were removed, it was noted that pistons 2, 4, 5 and 6 were at or almost at top dead center; the oil pan was removed with metal observed in the oil; four penetrating holes were observed in the bottom of the crankcase; after cylinders 2 & 3 were removed and the pistons withdrawn, the connecting rod bearings bore evidence of high heat distress and an absence of lubrication. The investigator stated that salvage personnel reported that only about a quart of oil was drained from the oil sump prior to the engine being prepared for teardown. The investigator also reported that connecting rods 2, 3, 4, 5 and 6 were separated from the crankshaft; only connecting rod 1 remained connected. The investigator stated that the airplane was then examined for evidence of oil streaks, and although oily, the accessory case, cowling interior, and fuselage bottom were not remarkable. The investigator also revealed that a tar-like sealant covered the bottom case halves, just aft of the propeller flange.

A review of maintenance records revealed that the engine had been removed for a major overhaul, then reinstalled on N56824 on April 30, 1998, at a tach time of 2,184.3 hours. Records further indicate that the airplane underwent its most recent annual inspection on November 11, 2005, at a tach time of 4,076.6 hours, 1,891.8 hours since the major overhaul. At the time of the accident the airplane's tachometer indicated 4,140.0 hours, or 1,956 hours since the engine's major overhaul. The pilot reported that the recommended Time Between Overhauls for the engine is 2,000 hours.