An Air New Zealand flight that had to turn around because it did not have permission to land in China was the fault of the airline, say aviation commentators.
The flight of the NZ289 to Shanghai from Auckland late last night was returned approximately five hours after the trip after it was discovered that the plane was not allowed to land.
A statement from Air New Zealand said: "It is a normal process to obtain a flight plan approved by local authorities before departure and this was done on this occasion and approved by the Chinese authorities.
"Unfortunately, during the flight it was discovered that this particular aircraft did not, in fact, have the necessary permission to land."
Independent aviation commentator Irene King said that such an incident was highly unusual and that she only knew of another case of this happening with an Air New Zealand plane.
He said it was likely that, even if the airline had requested that a plane land, suddenly a different plane would be included to land on the other side, something that the Chinese authorities would not have accepted.
"China is very restrictive in submitting applications for the landing slots." Normally, airlines are obsessed with their systems, as they submit applications for landing slots days, weeks, months before.
"Clearly, there has been a serious administrative problem 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 a mistake for the airline to commit it.
"It's very unusual, basically, it should not have happened.
"Under the Civil Aviation Law, under compensation, passengers can request up to 10 times the amount of compensation because this is not an act of God or an engineering or technical problem.
"This is clearly an administrative matter, well, I call it a robbery and the passengers have to submit an application and they are entitled to compensation, it should not have happened."
Veteran flight instructor Warren Sattler reiterated his comments; saying that the Chinese authorities were fans of following the rules.
"It may have been included in the list as a 777 and it could have taken a 787 instead.
"The Chinese, because of all the military airspace there, are very, very particular.
"This is just an assumption on my part, that Air New Zealand, for whatever reason, may have decided instead of putting a 777, putting a 787."
Eric Hundman, assistant professor at the Shanghai campus of the University of New York (NYU), told the Herald the flight took off from Auckland as scheduled near midnight the night before, but "halfway through our flight, the pilot informed us that the Chinese authorities had not given this plane permission to land, so we had to give the return".
"A problem of permits, supposedly," he said.
The flight returned to Auckland around 9:30 this morning, said Hundman.
Shortly after 11.30 this morning, Hundman was sent a text message from Air NZ that read: "As advised on board, the aircraft operating your flight did not have the regulatory approval to land in China and had to return to Auckland. "
A small compensation package included a $ 30 coupon for the meal.
The prime minister, Jacinda Ardern, did not receive information about the situation when she was asked about it at the Big Gay Out event in Auckland.
She said it sounded like an operational issue for the airline.
Foreign Minister Winston Peters refused to comment on the matter or was informed by the Ministry of Foreign Affairs and Trade (Mfat), and forwarded all questions to the ministry.
"The government is aware of this issue," said a Mfat spokeswoman.
"Air New Zealand has clearly explained that this was caused by a technicality in the flight plan permitting process, and any questions should be directed to the airline."