Cessna P210N N732JL accident near Glendale, California

Probable cause

The partial loss of engine power during descent for reasons that could not be determined because postaccident examination of the engine did not reveal any anomalies that would have precluded normal operation.

NTSB analysis

The pilot reported that during a cross-country flight, as he descended below 9,000 feet mean sea level, he encountered a severe surging of the engine and a reduction in power. The pilot declared an emergency, and he was advised by air traffic control of the two nearest airports. The pilot maneuvered the airplane towards one of the airports. Due to the reduction in power and loss of altitude, the pilot determined that he would be unable to land at the airport, and, therefore, he elected to land on a city street. The airplane impacted trees and a telephone pole before coming to rest inverted in the front yard of a residence.

Postaccident examination of the airframe revealed no pre-impact mechanical malfunctions or failures that would have precluded normal operation. The engine was removed from the airframe and prepared for an engine test run. The engine was started and operated for several minutes at various power settings. Further testing of components from the turbocharger system revealed no anomalies that would have precluded normal operation. The cause of the surging and partial loss of engine power could not be determined.

Text from the NTSB. Open the NTSB docket for WPR12FA222 for the full record.