A brand new Air New Zealand A321neo on a delivery flight from Germany was forced to turn back when Iran claimed it have the necessary clearance to fly in its airspace.
It was the fourth A321neo set to be delivered to Air NZ.
The route the aircraft takes to get from Germany to Auckland involves stops in Oman, Kuala Lumpur and Cairns, which requires around a dozen different airspace clearances to be given.
Each clearance is handled differently, by different authorities; but gaining clearance to fly over another country is common practice for all international airlines.
Air NZ said there was a last minute delay in the delivery process, which meant the flight had to leave for Oman before paperwork clearance had been received.
"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," an airline spokesperson said.
The aircraft will arrive in Auckland on Thursday evening.