Yoga (illustration)
Yoga (illustration)Nicky Kelvin/Flash 90

A 72-year-old South Korean retired farmer was on his way home from Hawaii with his wife after celebrating their 40th anniversary, when he suddenly decided to do yoga on the plane - things only got worse from there.

Hyongtae Pae forced the United Airlines flight from Honolulu to Narita Airport in Japan to turn back to Hawaii, after he was asked to sit in his seat and instead went on a rampage, according to the FBI criminal complaint published by The Guardian on Thursday.

Pae told the FBI that during the flight last Saturday he didn't want to sit in his seat during the meal service.

Instead, the 72-year-old decided to make his way to the back of the plane where he proceeded to do yoga.

Concerned flight attendants asked him to return to his seat, at which point he began yelling at them - then he started shoving his wife.

"Pae pushed his wife because she was trying to make him stop. He felt that she was siding with the flight crew," revealed the FBI report.

Things went further downhill from there, as the elderly ex-farmer tried to headbutt and bite US Marines who were passengers on the flight and tried to get him to sit down, according to assistant US attorney Darren Ching who spoke at Pae's detention hearing Wednesday.

Aside from assaulting his wife and Marines, he also threatened to kill passengers and yelled "there is no God," according to the complaint.

How did Attorney Jin Tae Kim try to explain his client's midair breakdown? According to the lawyer, intense sleep deprivation was the culprit.

Kim explained that Pae only recently began learning yoga to help him deal with anxiety. He said the retired farmer was sleep deprived during the vacation, noting that Pae told the FBI he hadn't been able to sleep for the previous 11 days.

In the hearing on Wednesday, attorney Ching said that the violent passenger shouldn't be released because he poses a danger to his wife, himself and others. He added that Pae is now on suicide watch at the Honolulu federal detention center.

US magistrate judge Kevin Chang ordered Pae's release on $25,000 bond, stipulating that he could not leave the island of Oahu, and that he must undergo a mental health evaluation.

The judge rejected a request to let Pae return to South Korea, as doing so would allow him back on a plane - possibly setting the stage for another surprise yoga session.