No charges are to be laid against the American passenger whose allegedly verbally aggressive, racist behaviour ended with a New Year's Day San Francisco-bound flight from Sydney being diverted to Auckland.

Passengers said the man embarked on a "racist" rant towards two passengers who'd been seated on either side of him on the United Airlines flight.

Flight UA870 departed Sydney at 1.14pm local time on Sunday and was near Tonga when it was diverted to Auckland.

The 252 passengers were put up in hotels as the cabin crew and pilots got enough rest, before the flight took off more than 24 hours later, on Monday evening.


Aviation expert Irene King told 1news that the disruption would cost the United Airlines around $150,000 for the one flight.

She said New Zealand law can apply when international aircraft land here.

"They've obviously got serious concerns about the safety of the aircraft and obviously the passengers on board," King said.

Despite the delay - which saw many passengers return home, or get to their holiday destination, two days later than planned - no charges are to be laid against the man.

A New Zealand police spokeswoman said the 42-year-old man had been detained until he was to be sent back to his point of origin.

Police attend the incident onboard the United Airlines flight diverted to Auckland. Photo / Supplied
Police attend the incident onboard the United Airlines flight diverted to Auckland. Photo / Supplied

She said the decision on whether to lay charges was made on a case-by-case basis, but she understood that in this instance none was being laid.

This morning one of the passengers, Peter Barrett, wrote into the Herald, hours after he expected to get to the United States.

He described the man, seated near him, as being so aggravated it looked as if he was on a "short path to physical violence" and left many passengers fearful as to where it would end.

"He seemed agitated, scribbling in a dog-eared copy of Catcher in the Rye," Barrett said. "At one point he went to the bathroom for 20 minutes which raised more than a few eyebrows.

"The behaviour seemed more like a pharmacological excess or deficit than simple alcohol."

Barrett said crew did an "exemplary job" of de-escalating the situation despite his neighbour calling them "little 'f******' and 'fat-arse'".

Another passenger, Nathan Urquhart, said seeing the man hole himself up in the bathroom for 20 minutes was a little nerve-racking.

"He continued the name calling on and off for quite a few hours," Urquhart said. "The United reps told me and four other gentlemen about hold-down tactics in case he got physical."

He said they were over Tonga when the decision was made to land.

"I overheard the pilot requested Fiji or American Samoa for us to land, but that was denied, so we back-tracked to Auckland for 2.5 hours and had to burn a tonne of fuel so as not to land heavy."

Footage shared on social media yesterday showed the man in a verbal exchange with one of the cabin crew saying it would be "cool" if the flight was diverted because of him and calling her a "fat-arse".

However, it seemed his happiness at this turn of events would be short-lived. Another video sent to the Herald by a passenger this afternoon showed him being more than a little bit disgruntled once in Auckland.

"Take my picture," he tells the man behind the camera phone. "I'm the guy they stopped the plane for because I complained."

A man was arrested after he allegedly became abusive onboard a New Year's Day flight bound for San Francisco, leading to it being diverted to Auckland.

He's then seen talking loudly on the phone to someone about sending his child to Auckland and getting his father to prepare a lawsuit.

"...I don't even care if you come, send my son to Auckland," he said into his phone.

"Tell my Dad to get his law firm ready, coz United Airlines just diverted the f*****g plane because I complained to some fat c*** who got in my f*****g face."

He then proceeded to abuse the man filming.

"It's not my fault, you ******* f*****t."

Another video posted on social media shows him appearing somewhat calmer as the New Zealand police escorted him off the flight.

Immigration New Zealand said the man was held in police custody until arrangements could be made for him to be flown back to the United States.

United Airlines spokeswoman Erin Benson couldn't say this evening what, if any, further action would be taken against the man.

Despite the encounter, Barrett has chosen to focus on the bright side, saying it had given him the desire to revisit Auckland.

"On the bright side my family and I had a lovely breakfast in North Shore, got a spectacular overview of Auckland from the Sky Tower and met smart and friendly locals.

"We will be back soon for a much longer stay."

Other photos on social media show the passengers making the most of the unexpected stop, sharing a glass of wine together and paying kudos to the attendants for remaining calm.

According to the International Air Transport Association, representing 83 per cent of total air traffic, there have been more than 49,084 reported cases of "unruly passenger incidents" on flights between 2007 and 2015.

However, despite the "serious consequences" the IATA said there were "loopholes in existing laws" that saw many cases go unpunished.

The association said it was working on enhancing the international legal framework to ensure there's a "sufficient deterrent" to such behaviour.

"In addition, IATA has been advocating for a review of the international legal framework, to ensure that Governments have the legal powers they need to deal with unruly passengers."