A United Airlines flight had to be turned around after a pensioner started screaming at the crew and wanted to practise yoga instead of sitting in his seat.
Hyongtae Pae refused to sit in his assigned seat during the meal service on the flight from Hawaii to Japan, according to The Independent.
Instead, he went to the back of the plane to do yoga and meditate.
When he was asked to return to his seat, he became angry and started "shoving his wife", the FBI said in a criminal complaint.
Pae refused to sit down and threatened to kill passengers on the flight on 26 March, shouting that "there is no God", the FBI's complaint said.
According to the Indian Express, he also tried to headbutt and bite some Marines who were on the flight and were attempting to get him back into his seat.
Pae was arrested after the pilot decided to divert the plane, which was travelling from Honolulu International Airport to Narita International Airport, back to Hawaii.
“Pae pushed his wife because she was trying to make him stop,” the FBI complaint said. “He felt that she was siding with the flight crew.”
He had only recently took up yoga to help with anxiety, his defense attorney Jin Tae JT Kim said at his detention hearing on Wednesday. Pae told the FBI he hadn’t been able to sleep for 11 days.
Pae is now on suicide watch at the Honolulu Federal Detention Center, according to the Associated Press.
US Magistrate Judge Kevin Chang said he could be released, but with conditions including not leaving the island of Oahu in Hawaii, and undergoing a mental health evaluation.
Chang denied a request for Pae to return to his native Korea, because it would mean him getting on a plane again.