Airline staff first gave him some snacks but Thede allegedly got up and demanded more. As passengers and crew became alarmed at the man's erratic behavior, the pilot decided to touch down in Belfast, after first dumping 50,000 liters of aviation fuel to make the stop.

The passenger, Jeremiah Mathis Thede, from California, allegedly got out of his seat 15 minutes into the flight from Rome and demanded "nuts or crackers" and refused to sit down again until he got a snack.

A United Airlines Rome-Chicago flight on Saturday had to be diverted to Belfast, Northern Ireland, because an unruly passenger repeatedly demanded bags of nuts.

An argument on a transatlantic United Airlines flight over a bag of nuts could run up a bill of £350,000 ($553,000) for the airline, according to a report on U.K. news site The Telegraph.

Once grounded, the 282 passengers had to wait almost 24 hours to take off again because getting under way immediately would have broken the crew's legal flying limit. Almost all the passengers had to sleep on the terminal floor.

On Monday, Thede appeared at Coleraine Magistrates' Court in Northern Ireland on Monday charged with endangering the safety of the aircraft, disruptive behaviour on board and common assault against a stewardess. Thede denies the charges against him, saying the pilot overreacted, however.

A constable with the airport constabulary told the court the trouble began when Mr Thede allegedly got up 15 minutes after take-off, with the seat belt lights still on, and demanded snacks. He said Thede refused to sit back down again until he obtained a snack.

Asked by a prosecution barrister in the court to assess the cost of the incident, the constable replied: "It would be upwards of £300,000 to £350,000. There is compensation for passengers. There were 269 passengers lying sleeping on the floor of the terminal because there were no hotel rooms found for them."

It's not the first time that nuts on a plane have caused a massive headache for both airlines and passengers. In December, the daughter of the chairman of Korean Air forced the plane she was travelling in to return to an airport gate in New York and offload one of the airline's stewards -- because she didn't like the way she had been served some macadamia nuts.

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- By CNBC's Holly Ellyatt, follow her on Twitter @HollyEllyatt. Follow us on Twitter: @CNBCWorld

