A Convair C-131B Samaritan cargo plane was destroyed when it ditched in the Atlantic Ocean about 32 miles east of the Miami-Opa Locka Executive Airport (OPF), Florida, USA. The captain was fatally injured, and the co-pilot was seriously injured. The airplane was operated by Conquest Air Cargo on a cargo flight from Opa Locka to Nassau, Bahamas and back. The flight to Nassau was normal until the co-pilot had to adjust the left engine propeller control to adjust speed for cruise flight. When he manipulated the control, there was no movement on the gauge and the power was stuck at 2,400 RPM. He tried to re-set the propeller control circuit breaker, but to no avail. The captain equalized power on both engines and the flight was uneventful to Nassau. Once on the ground, the captain asked the co-pilot to send a text message to maintenance control, but the message never transmitted. The captain told the co-pilot not worry about it and if they were unable to re-set the propeller control on the ground during the engine run-up then they would shut down and call maintenance. The co-pilot stated to the NTSB that before they began the accident flight, the engines started normally and both propellers were cycled. The left propeller control had re-set itself and they departed for Opa Locka. The co-pilot was Pilot Flying on the return leg and everything was normal until climbing through 4,000 ft when the left engine propeller control stopped working and the power was stuck at 2,400 RPM. The captain tried to adjust the control and bumped the power up to 2,700 RPM. The captain took control of the airplane and tried to stabilize the power on both engines. He leveled off at 4,500 ft, cancelled their instrument flight rules flight plan, and flew via visual flight rules direct to Opa Locka. The flight was normal until they began their descent down to 1,500 ft. The right engine suddenly backfired and began to surge. The flight crew used the checklist to feather the propeller and shut down the engine. Shortly after the left engine backfired and began to surge. As the captain flew the airplane, the co-pilot attempted to handle the emergency. Once he realized they were too low and were going to ditch, he asked the captain what he wanted to do. The captain told him to declare a May Day and brace for impact. The co-pilot said the impact with the water was violent and the tail had separated from the empennage. The fuselage was filling up rapidly with water. He unbuckled his seat belt/shoulder harness, grabbed the life raft and exited the airplane. Probable Cause: “The captain’s decision to continue with the flight with a malfunctioning left engine propeller control and the subsequent loss of engine power on both engines for undetermined reasons, which resulted in ditching into the ocean. Contributing to the accident was the first officer’s failure to challenge the captain’s decision to continue with the flight.”