Incident Summary
Shortly after takeoff, the pilot reported hearing a loud bang. The aircraft then began to vibrate severely, and the engine developed partial power. The aircraft would not climb, and the pilot was able to maintain only a 100 feet per minute descent. Unable to return to the airport, the pilot ditched the aircraft in the ocean.
Findings
Inspection of the propeller blades revealed leading edge damage along the outboard 4 to 5 inches of the blades, with some polishing of the cambered side. One blade was bent forward and missing approximately 4 inches of its tip. About one inch further from that damage, a gouge was found on the leading edge. The other blade was bent rearward, and on its leading edge approximately 4 inches from the tip, a gouge and a crack about one inch long were noted.
The engine contained a considerable amount of rust and corrosion from being in contact with salt water. No other mechanical failures or malfunctions could be identified during the inspection.