Piper PA-28-181 N9160Q accident near Waihee-Waiehu, Hawaii

Probable cause

The loss of engine power for reasons that could not be determined because postaccident examination did not reveal any anomalies due to saltwater immersion.

NTSB analysis

During a cross-country flight, the pilot noticed that the engine had begun running roughly; he then performed a series of troubleshooting procedures, which corrected the problem. About 5 to 10 minutes later, the engine began running roughly again, and the pilot performed the troubleshooting procedures a second time. Shortly thereafter, the pilot noticed that the engine rpm was fluctuating between 1,500 and 2,450 and that the airplane would not maintain altitude. The pilot initiated a forced landing to a field, and, during the landing roll, the airplane struck bushes and trees before it came to rest in a nose-low position. During the recovery of the airplane using a helicopter long-line operation, the wreckage began to spin. The helicopter pilot jettisoned the external load cable attached to the airplane. Subsequently, the wreckage descended and impacted water just offshore from the accident site. The engine and one wing were recovered from the water about 2 days later. Postaccident examination of the recovered engine revealed signatures consistent with salt water submersion and severe corrosion. The saltwater immersion destroyed much of the evidence, and the reason for the loss of engine power could not be determined.

Text from the NTSB. Open the NTSB docket for WPR13LA275 for the full record.