A New Zealand Air Force Orion is stranded on Niue after being forced to land there four days ago with an engine problem.
The aircraft was on fisheries surveillance duty.
A replacement engine part was flown to the island by an RNZAF Hercules at the weekend, but test flights found the engine was still faulty.
A second replacement engine part is expected later this week, with the aircraft due back in Auckland by the weekend.
