What happened
The aircraft was operating a mail route from Oakland, California, to Auckland, New Zealand, with scheduled stops in Honolulu, Kingman Reef, and Pago Pago. Approximately one hour after departing Pago Pago during the early morning hours, the crew encountered technical difficulties. An oil leak developed on engine number 4, which was subsequently shut down. The captain decided to return to Pago Pago. During this phase, the crew initiated a fuel dump procedure. Shortly after, the seaplane, identified as the 'Samoan Clipper', crashed into the sea approximately 120 kilometers south of Pago Pago. Only minimal debris was recovered from the water surface. All seven occupants on board were killed in the accident.
Findings
Investigations indicated that the crash likely resulted from an in-flight fire or explosion. It is theorized that gasoline vapors became trapped beneath a wing flap after it was extended during the fuel dumping process. This accumulation of vapors led to the catastrophic event that caused the loss of the aircraft.