Vietnam-bound Harry Frazer Cranwell, 32, had drunk five cans of beer and another glass of alcohol on MH0130 on Sunday night, Malaysian national news agency Bernama reported.
A Malaysian magistrates court yesterday [Wednesday Malaysia time] heard that an air stewardess saw Cranwell holding the handle of the emergency door of the aircraft and attempting to open it.
Cranwell, reportedly a restaurant manager from Auckland, was moved to another seat and the flight's captain informed.
At the Kuala Lumpur airport transit, Cranwell was arrested and charged with endangering an aircraft and the lives of those onboard by attempting to open the emergency door, Bernama said.
The charge laid under civil aviation rules carries a maximum sentence of three years in jail.
Cranwell, appearing in the dock wearing an orange prison jumpsuit, pleaded guilty to the charge.
His lawyer, Zaflee Pakwanteh, Bernama reported, said Cranwell was flying to Vietnam for a holiday with friends. He was remorseful and apologetic, the court heard.
Two days in police custody had "really taught him a lesson", the lawyer was reported as saying.
Magistrate Mohamad Izwan Mohamed Noh told Cranwell it was a serious offence with the potential to endanger the lives of other passengers and crew members.
He warned him to never repeat his actions.
Bernama reports he had tears rolling down his cheeks as he told the judge: "I promise, sir".
Cranwell was fined 6000 Malaysian Ringgit ($2226) in default of 12 month's jail.
