What happened
During the first takeoff attempt, the pilot observed fluctuations in the Brake Mean Engine Pressure (BMEP) on the number two engine. Following this observation, the pilot decided to abort the takeoff. After performing two subsequent engine run-ups that showed no further irregularities, a second takeoff attempt was initiated.
As the aircraft type climbed through 200 feet MSL, a loud bang or backfire originated from the number two engine. This was followed by a significant drop in BMEP, creating a 150 BMEP discrepancy between the first and second engines. Concurrently, the engine oil pressure decreased while the engine oil temperature increased rapidly, accompanied by heavy vibrations throughout the airframe.
In response to the failure, the first officer reduced the power on the number two engine to 'dry' power, which triggered a second audible backfire from the same engine. The first officer then feathered the propeller on the number two engine. Due to the inability to maintain altitude, the pilot performed a ditching in a salt water lagoon. The flight crew followed the established engine-out emergency procedures and checklists during the event.
Findings
An inspection of the wreckage by an FAA Inspector revealed that the propeller on the right engine had not been fully feathered at the time of the accident. Additionally, the wing flaps were found to be extended at approximately three degrees. The aircraft remained submerged and was not recovered from the water until 70 days after the incident.