Mkii Corporation Lancair Legacy 2000 N199L accident near Bend, Oregon

Probable cause

A total loss of engine power due to the fatigue failure of the Number 3 cylinder connecting rod.

NTSB analysis

While at 9,000 feet, the engine lost oil pressure, suddenly oversped (3,560 rpm), and lost power. The pilot made a dead-stick approach to a nearby runway. During the landing flare the airplane's main landing gear impacted a trench and sheared off just short of the runway. The airplane slid down the runway on its nose gear, main mount struts, and tail. The airplane then veered off to the right and departed the runway. Examination of the engine revealed a 4- to 5-inch diameter hole in the top of the engine case above the No. 3 cylinder. Further examination revealed that the No. 3 connecting rod of the engine had failed due to fatigue just below the wrist pin. The loose end of the connecting rod produced metal shavings that obstructed the oil pickup tube as the crankshaft continued to rotate. The blocked tube led to oil starvation, propeller overspeed, and catastrophic engine failure. Material Laboratory testing revealed that the connecting rod fatigue fracture was located in a decarburized region of the rod. The engine manufacturer could not identify the connecting rod as a component supplied by them.

Text from the NTSB. Open the NTSB docket for LAX08LA168 for the full record.