Accident Summary
On September 1, 2011, at about 1840 Pacific daylight time, a UH-1H helicopter (registration N205PJ), manufactured by Arrow Falcon Exporters, Inc., sustained substantial damage when it rolled over during an emergency landing. The accident occurred near Stockton, California, following a total loss of engine power. The commercial pilot, who was the sole occupant, received minor injuries. The helicopter was being operated by P.J. Helicopters of Red Bluff, California, under 14 Code of Federal Regulations Part 91 as a cross-country repositioning flight. Visual meteorological conditions prevailed. The flight had originated from Tracy, California, about 10 minutes prior to the accident. A company visual flight rules flight plan was on file and had been activated.
Pilot Report
The pilot reported that during cruise flight, he observed a fluctuation in the engine oil pressure followed by the illumination of a red warning light indicating low oil pressure. While performing a precautionary landing, at approximately 10 feet above ground level, the engine experienced a total loss of power. The helicopter subsequently landed hard on uneven terrain and rolled onto its left side.
Postaccident Examination
A postaccident teardown examination of the engine, supervised by a Federal Aviation Administration inspector, revealed that a gear tooth on the starter-generator drive gear had separated. The separated tooth jammed the accessory gear drivetrain, causing failure of the engine oil pump. This led to catastrophic engine failure due to oil starvation. The reason for the failure of the gear tooth was not determined.