Robinson Helicopter Company R44 II N510KJ accident near Calexico, California

Probable cause

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

NTSB analysis

The commercial pilot was conducting an agricultural application flight. He reported that, after reaching a field and during the first turn, the engine experienced a partial loss of engine power. During the subsequent attempt to land, the pilot turned the helicopter to avoid power lines. The helicopter subsequently landed hard and rolled onto its right side.

A postaccident examination of the airframe and engine revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation. The engine was test run with no anomalies noted. The reason for the partial loss of engine power could not be determined.

Text from the NTSB. Open the NTSB docket for WPR15LA096 for the full record.