Incident Summary
After departing from Mammoth Lakes Airport (elevation 7,128 feet), the aircraft's engine power began to deteriorate, and the climb rate was slow. The flight took place during dark conditions.
Emergency Landing
The pilot, unable to return to the departure airport, decided to conduct an emergency landing on the northbound lanes of Highway 395. In that area, all vehicular traffic was moving southbound, and the pilot had difficulty seeing the northbound lanes. During the landing, the right wing of the aircraft struck a snowbank located on the right side of the road.
Investigation
An investigation into the engine malfunction did not identify a specific cause. The engine was examined, but no reason for the power deterioration could be determined.