What happened
While operating in the cruise phase of flight, the pilot experienced a mechanical failure involving the right engine. The right engine cowling partially detached from the airframe, and the forward cylinder on the left side of the engine separated from the engine block. This structural failure immediately triggered a fire within the engine compartment.
In an attempt to manage the emergency, the pilot tried to feather the propeller, but the mechanism failed to respond. The pilot then began a descent to facilitate fire suppression. Although the crew successfully extinguished the flames, the aircraft became difficult to handle once the pilot leveled off, as directional control could no longer be maintained.
Due to the loss of control, the pilot performed a ditching maneuver. Following the impact with the water, the pilot and the passenger managed to exit the aircraft type (unspecified model). The pilot was able to move the passenger, who sustained serious injuries, to a nearby island. Both individuals were rescued the following day.
Findings
Because the aircraft was not recovered from the site, investigators were unable to determine the specific reason why the cylinder separated from the engine. However, maintenance records for the aircraft revealed that on August 27, 1991, the number five cylinder of the right engine had been replaced. Additionally, the number one cylinder had been removed and reinstalled following a repair. No other entries regarding cylinder work on the right engine were noted in the logbook prior to the incident.