The airline said in a statement it has been operating all regular international schedules since Saturday, after a replacement mechanical part for the Boeing 737 was sourced.
Final mechanical work would take place later this month to replace the loan auxiliary power unit that was currently fitted. This work would be conducted overnight, so it was not expected to affect any flights.
The airline said the backlog of stranded customers had been resolved through recovery flights and assistance from other airlines, including Solomon Airlines, Nauru Airlines and Fiji Airways.