Schweizer 269C N2099S accident near Titusville, Florida

Probable cause

An engine failure due to the separation of the engine crankcase, which resulted from the lateral movement of the center main bearing and the subsequent blocking of the oil feed hole that supplied oil to the No. 2 connecting rod, which then led to its failure due to oil starvation.

NTSB analysis

Shortly after takeoff, the student pilot notified an air traffic controller that the helicopter was vibrating and requested to return to the airport. The flight instructor reported that, about 1/2-mile east of the airport, he and the pilot heard a loud "bang." In response, the student pilot lowered the collective and then the flight instructor took over the controls and entered an autorotation. The helicopter touched down hard on a road, which resulted in substantial damage to the tailboom and diagonal strut. Postaccident examinations revealed that the engine crankcase was breached and that the No. 2 cylinder rod had failed. Further examinations of the engine revealed evidence that the center main bearing had spun in the bore and moved laterally. This movement covered the oil feed hole that supplied oil to the No. 2 connection rod and led to its failure due to oil starvation.

Text from the NTSB. Open the NTSB docket for ERA13LA180 for the full record.