Robert John Coppack, 40, of La Verne, California, will remain in custody until a detention and probable cause hearing Monday in federal court.
According to an FBI affidavit, two women sitting with Coppack complained about his behavior on the overnight US Airways flight Tuesday, prompting the crew to steer him toward the back of the plane. Coppack then groped a retired flight attendant as he walked down the aisle, the affidavit said.
Coppack, who told his seatmates he had been drinking vodka, was also aggressive and verbally abusive, the affidavit said. He was detained on board by an air marshal on the flight, and later charged with intimidating the crew and interfering with their work.
Neither a public defender assigned to his case nor relatives listed at his California address returned calls for comment Wednesday.
The plane arrived at Heathrow Airport in London about four hours late, airline spokeswoman Michelle Mohr said.
Coppack was traveling on a British passport, and told officials he has dual citizenship, the affidavit said.