What happened
The aircraft taxied to the active runway and departed with approximately 15 to 20 gallons of fuel in each main tank and about 5 gallons in each tip tank. While climbing through 2,800 to 3,000 feet above the water, the pilot experienced a sudden loss of engine power. At an altitude between 800 and 1,000 feet, the pilot had retracted the flaps, turned off the electric-driven fuel pump, set the manifold pressure to 25 inches of mercury, reduced propeller RPM to 2,500, and leaned the mixture to 18 GPH.
The pilot noted that the power loss felt as though the propeller RPM had shifted from a low pitch to a high pitch. Although the propeller continued to rotate at 2,300 rpm, the engine manifold pressure stabilized between 15 and 17 inches of mercury. In an attempt to restore power, the pilot set the mixture to full rich and turned the electric-driven fuel pump to the "ON" position, but there was no recovery. The pilot then switched the fuel selector from the right main tank to the left main tank, but the engine remained unresponsive.
During the subsequent descent, engine and system instruments remained within normal operating ranges. The pilot attempted to manipulate the throttle control, which caused manifold pressure to drop to 10 to 12 inches of mercury before returning to 15 to 17 inches. The pilot also cycled the left and right magnetos to the "OFF" position and back to "ON" in a different order, but the engine did not respond. The pilot was unable to select an alternate air source during the descent. Ultimately, the pilot ditched the airplane, and the occupants exited into the water.
The investigation
Approximately one month after the accident, the engine was recovered from the ocean for examination by the Safety Board. During this inspection, investigators identified no preimpact failures or malfunctions.