A brand new Air New Zealand Airbus plane on a delivery flight from Hamburg did a U-turn approaching the Iranian border and returned to the German city because of a paperwork problem.
The turnaround of the A321neo came after clearance to fly over Iran didn't come through as expected.
Problems with the flight on February 15 came just days after a China-bound Air New Zealand Dreamliner turned back to Auckland - that too was apparently because of a paperwork problem.
Flight NZ6093 was nearly four hours into its flight when it did a 180-turn while travelling at 39,000 feet above Erzincan in Turkey. It returned to Hamburg, one of two European sites where the narrow body planes are assembled.
Air New Zealand says because of a tight schedule the aircraft left Hamburg before clearance paperwork had been received to overfly Iran.
''We had received assurances by our delivery flight planning agent that the Iranian clearance paperwork would come through during the flight. Unfortunately this was not received in time and the decision was made to return to Hamburg,'' a spokeswoman said.
''While the turn back is unfortunate, the nature of obtaining a chain of interlinked clearances means scenarios of this nature are not uncommon.''
The aircraft has since departed Hamburg and is expected to arrive in Auckland late on tomorrow evening after stopping in Oman, Kuala Lumpur and Cairns.
Routine ferry flights have no passengers and typically just a roster of pilots and a handful of other airline staff on board.
Smaller, narrow body aircraft on ferry flights hopscotch their way to their destination because they don't have the range of bigger planes.
This means a series of clearances.
Each process is managed differently and has different application deadlines and parameters, the airline said.
''For instance one jurisdiction may require proof of an existing clearance to land elsewhere, another may outline a set period of time when the aircraft is able to land within that airspace, and some require application within a short window of the flight departing.''
Strict rules cover Iranian air space and the United States issued a new warning to planes flying in the area late last year.
It warned airlines to exercise caution when operating in Iran's airspace, citing concerns over military activity including an unnamed US civil operator being intercepted by fighter jets.
Tension between Iran and New Zealand ally the United States has increased since President Trump ditched a nuclear deal.
Air New Zealand is buying 13 Airbus neo aircraft (seven A321neos and six A320neos) to replace the A320 fleet that currently operates Tasman and Pacific Island services and a further seven Airbus A321neos for expected domestic network growth.