What happened
Approximately 10 minutes after takeoff, while cruising at an altitude of about 800 feet AGL, the pilot noticed that the right engine's oil pressure was decreasing and the temperature was increasing. Two minutes later, the right engine began running roughly and backfiring, prompting the pilot to shut the engine down.
During the emergency, the pilot mistakenly turned into a small bay instead of heading toward the departure airport. Due to the presence of houses and high terrain on the left side of the aircraft, the pilot attempted a slow turn to the right. As the aircraft entered a low airspeed buffet, the pilot feared the plane was about to go inverted. In response, the pilot cut power to the left engine, leveled the wings, and ditched the aircraft in shallow water near the shoreline. The occupants were not injured.
The investigation
The investigation determined that during the retraction of the landing gear following takeoff, the right main landing gear retraction chain broke. This broken chain punctured the oil tank of the right engine, causing all the engine oil to drain out. Aside from this failure, no mechanical problems were found with either of the two engines.