Cessna 182P N430ML accident near Alachua, Florida

Probable cause

A loss of engine power due to the failure of the camshaft gear teeth and crankshaft gear teeth for undetermined reasons.

NTSB analysis

While the pilot was maneuvering the airplane to set up a visual approach, the engine lost partial power. The pilot attempted to restore full engine power but was unsuccessful. Subsequently, he made a forced landing in a field, and the airplane nosed over. A postaccident examination of the engine revealed that it would only partially rotate by hand with resistance. Further examination revealed that the camshaft gear was missing nine teeth and that one tooth was damaged. The crankshaft gear was missing four consecutive teeth, and one tooth was missing from another location on the gear. A metallurgical evaluation of the camshaft gear, crankshaft gear, an exhaust valve, and a lifter revealed that the components met all the material properties requirements. The fracture surfaces on the camshaft and crankshaft gears were damaged due to post-separation contact. Debris from the oil sump was identified as nitrided gear material and lifter fragments. The engine had accumulated about 12 hours of operating time since its most recent inspection, which included an oil change. At the time of the accident, the engine had accumulated a total time of 750.7 hours. According to the owner and the engine maintenance log, no propeller strikes had occurred since the engine was installed on the airframe.

Text from the NTSB. Open the NTSB docket for ERA11LA190 for the full record.