NTSB Identification: NYC00LA050.
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Accident occurred Saturday, December 11, 1999 in READING, PA
Probable Cause Approval Date: 08/13/2001
Aircraft: Mooney M20-C, registration: N6715U
Injuries: 1 Minor,2 Uninjured.

NTSB investigators may not have traveled in support of this investigation and used data provided by various sources to prepare this aircraft accident report.

Shortly after takeoff, the pilot experienced a loss of engine power, and performed a forced landing. Examination of the engine revealed a 1-inch by 6-inch hole, in the engine crankcase adjacent to the number two cylinder, and a fractured number two cylinder connecting rod. Additionally, the crankshaft installed in the engine, required the installation of sludge tubes in the crank-pins. Examination of the crankshaft revealed that the sludge tubes had not been installed. According to a representative of the engine manufacturer, the crankshaft installed in the engine was not approved for use in that model engine. Additionally, the absence of the crankshaft sludge tubes would not allow pressure oil to reach the connecting rod bearings and the connecting rod bearings would only receive splash, vapor and centrifugal force oil. The engine had been operated for about 940 hours since it was overhauled on April 16, 1990 and there were no logbook entries which indicated the crankshaft had been removed or replaced since the overhaul.

The National Transportation Safety Board determines the probable cause(s) of this accident to be:

The failure of the number two connecting rod after an improper overhaul by maintenance personnel.

Full narrative available

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