What happened
A pilot was conducting a routine banner tow flight around the North Myrtle Beach area when the engine began to run rough at an altitude of 500 feet. The engine continued to operate poorly for approximately 45 to 60 seconds before experiencing a complete loss of power. After unsuccessful attempts to restart the engine, the pilot chose to ditch the Cessna (type not specified in source) in the Atlantic Ocean. The aircraft ditched approximately 125 yards from the coast and was subsequently recovered by witnesses at the scene.
The investigation
Post-accident examination of the aircraft revealed that saltwater had entered the engine and engine accessories. Following recovery, the saltwater was drained from the engine, after which the engine was started and a functional run was successfully completed. An analysis of carburetor icing charts indicated that weather conditions were favorable for the formation of carburetor ice. The pilot reported that carburetor heat was not applied during the flight.