Piper PA 22-135 N1348C accident near Livermore, California

Probable cause

A loss of control for reasons that could not be determined, because examination of the airframe and engine revealed no anomalies that would have precluded normal operation.

NTSB analysis

The airline transport pilot departed on a local night flight. Shortly after takeoff, he reported a control difficulty to air traffic control tower personnel; he stated that he was going to make a circle, and troubleshoot the issue. There were no further transmissions from the pilot. A witness about 1/2 mile away from the airport said that the airplane caught his attention when he heard the engine cut out. He looked up, but couldn't see the airplane as it was dusk. He finally saw two outboard lights, one on each wing, and realized that the airplane was in a nose dive. According to the witness, it was not spinning, and the engine sounded like it was at full throttle. Radar data indicated that the airplane departed about on runway heading, and about 2 minutes into the flight it began a 180° turn. The airplane lost about 1,100 ft of altitude in 18 seconds during the turn. The radar track continued in a straight line until ground impact. Postaccident examination revealed no anomalies that would have precluded normal operation of the airframe or engine or would have caused a control difficulty.

Text from the NTSB. Open the NTSB docket for WPR15FA174 for the full record.