About four and half hours into its flight early on Sunday NZ789 had to turn around over the Coral Sea after it was discovered it didn't have regulatory clearance to land in China.
Passengers were put up for the day at hotels or at the airport's Strata Lounge before they departed for Shanghai on a special service at 11pm last night.
A statement from Air New Zealand yesterday said: "It is normal process to get a flight plan cleared by local authorities prior to departure and this was done on this occasion and was approved by Chinese authorities.
"Unfortunately, it was discovered during the flight that this particular aircraft did not, in fact, have the necessary permit to land.''
Independent aviation commentator Irene King said such an incident was highly unusual and knew of only one other instance of this happening with an Air New Zealand aircraft.
She said yesterday it was likely that although the airline would have filed for an aircraft to land, a different aircraft was suddenly listed to land on the other side - something Chinese authorities would not have accepted.
"China's very restrictive to filing applications for landing slots. Normally, the airlines are obsessive with their systems - filing landing slots applications days, weeks, months in advance.
"Clearly, there's been a serious administrative cock-up for this to happen."
King said it was well-known among airlines and the aviation world that the Chinese were "very particular'' and strict about their airspace; so it was the airline's mistake to make.
"It's just highly unusual. Basically, it should not have happened.''
