Piper PA 28-161 N8466G accident near Miami, Florida

Probable cause

A partial loss of engine power for reasons that could not be determined because postaccident examination of the airplane revealed no mechanical anomalies that would have contributed to the power loss.

NTSB analysis

The private pilot was flying over the ocean and just off the coast when an air traffic controller asked him to descend to 500 ft. The pilot reduced engine power and applied carburetor heat until he reached the assigned altitude, and he then attempted to increase engine power and level off; however, even with the throttle full forward, the engine power remained at its previous setting. The pilot attempted to resolve the situation, but he was unable to maintain altitude and ditched the airplane in the ocean Although weather conditions were conducive to serious icing at glide power, the pilot had applied carburetor heat during the descent which should have melted any carburetor ice during the descent. A postaccident examination of the airframe and engine revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation. The cause for the partial loss of engine power could not be determined.

Text from the NTSB. Open the NTSB docket for ERA16LA103 for the full record.