A spokesperson says pilots did keep passengers updated, all the while landing the plane safely.
But the airline says pilots followed standard operating procedures.
The aircraft had been circling the airport for around an hour.
It's going to be operating five additional A320 services between the city and Auckland.
The plane was forced to turn back to Auckland.
Air NZ is claiming more than just desserts across the Tasman
Two of the airlines 787-9 Dreamliners' engines have to go to Singapore for maintenance.
AirNZ experts tell us exactly what's happening with their engines.
Around 6500 people are thought to be affected.
Further issues with Rolls-Royce engines for Air NZ.
Nine Air NZ planes are affected by an engine issue where more frequent maintenance checks are required than the manufacturer first directed.
It comes just days after the airline's high-profile split from Virgin Australia.
Perhaps unsurprisingly, Air NZ has flown high above most of its much larger competitors.